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Reilly PT, van Eps A, Stefanovski D, Pfau T. The influence of different horseshoes and ground substrates on mid-stance hoof orientation at the walk. Equine Vet J 2024; 56:598-606. [PMID: 37589397 DOI: 10.1111/evj.13990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 07/27/2023] [Indexed: 08/18/2023]
Abstract
BACKGROUND Horseshoes with modified contact surfaces combined with deformable ground substrates are used to change hoof orientation during mid-stance, for example, for therapeutic reasons. OBJECTIVES To measure the effect of horseshoes and ground substrates on sagittal and transverse plane hoof orientation at mid-stance using a dorsal hoof wall mounted triaxial accelerometer. STUDY DESIGN In vivo experiment, randomised crossover design. METHODS Differences in sagittal and transverse plane angles between standing and mid-stance of the left front hoof of six horses walking with regular horseshoes, egg bar, toe-wide, medial-wide, lateral-wide and three-degree egg bar shoes on turf, sand and hard ground substrates were assessed with linear mixed models with horseshoe and substrate type as fixed factors (p < 0.05) for each animal. RESULTS Hoof angles were significantly affected by horseshoe (p < 0.001), surface (p < 0.001) and the combination (p < 0.001). The sagittal plane angle increased in deformable ground substrates at walk-in mid-stance on turf [mean (±standard deviation): 2.6° (±3.8°)] and on sand [2.6° (±4.1°)] across all shoes. The greatest increase was observed with egg bar shoes [turf: 4.37° (±3.82°); sand 4.69° (±3.83°)]. There was a tendency for the hoof to sink laterally into deformable ground substrates among all shoes [turf: 1.11° (±1.49°); sand: 0.93° (±1.93°)]. Medial-wide shoes increased the lateral sinking [turf: 2.00° (±1.63°); sand: 1.79° (±1.58°)]. Lateral-wide shoes reduced the lateral sinking on turf [0.62° (±1.26°)] and induced a marginal medial sinking on sand [-0.007° (±2.03°)]. MAIN LIMITATIONS The substrate properties were not quantitatively assessed, and observations were limited to front hooves at the walk. A larger sample size would be preferable. CONCLUSIONS Mid-stance hoof orientation changes with specific combinations of shoes and ground substrates in the walking horse.
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Affiliation(s)
- Patrick T Reilly
- Department of Clinical Sciences, New Bolton Center, University of Pennsylvania, Kennett \Square, Pennsylvania, USA
| | - Andrew van Eps
- Department of Clinical Sciences, New Bolton Center, University of Pennsylvania, Kennett \Square, Pennsylvania, USA
| | - Darko Stefanovski
- Department of Clinical Sciences, New Bolton Center, University of Pennsylvania, Kennett \Square, Pennsylvania, USA
| | - Thilo Pfau
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
- Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
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Unnikrishnan G, Ilzhöfer P, Scholz A, Hölzl C, Götzelmann A, Gupta RK, Zhao J, Krauter J, Weber S, Makki N, Büchler HP, Pfau T, Meinert F. Coherent Control of the Fine-Structure Qubit in a Single Alkaline-Earth Atom. Phys Rev Lett 2024; 132:150606. [PMID: 38682979 DOI: 10.1103/physrevlett.132.150606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 03/11/2024] [Indexed: 05/01/2024]
Abstract
We report on the first realization of a novel neutral atom qubit encoded in the spin-orbit coupled metastable states ^{3}P_{0} and ^{3}P_{2} of a single ^{88}Sr atom trapped in an optical tweezer. Raman coupling of the qubit states promises rapid single-qubit rotations on par with the fast Rydberg-mediated two-body gates. We demonstrate preparation, readout, and coherent control of the qubit. In addition to driving Rabi oscillations bridging an energy gap of more than 17 THz using a pair of phase-locked clock lasers, we also carry out Ramsey spectroscopy to extract the transverse qubit coherence time T_{2}. When the tweezer is tuned into magic trapping conditions, which is achieved in our setup by tuning the tensor polarizability of the ^{3}P_{2} state via an external control magnetic field, we measure T_{2}=1.2 ms. A microscopic quantum mechanical model is used to simulate our experiments including dominant noise sources. We identify the main constraints limiting the observed coherence time and project improvements to our system in the immediate future. Our Letter opens the door for a so-far-unexplored qubit encoding concept for neutral atom-based quantum computing.
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Affiliation(s)
- G Unnikrishnan
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - P Ilzhöfer
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - A Scholz
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - C Hölzl
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - A Götzelmann
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - R K Gupta
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - J Zhao
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - J Krauter
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - S Weber
- Institute for Theoretical Physics III and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - N Makki
- Institute for Theoretical Physics III and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - H P Büchler
- Institute for Theoretical Physics III and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Pfau
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - F Meinert
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
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Pfau T, Bruce OL, Sawatsky A, Leguillette R, Edwards WB. Dirt Track Surface Preparation and Associated Differences in Speed, Stride Length, and Stride Frequency in Galloping Horses. Sensors (Basel) 2024; 24:2441. [PMID: 38676058 PMCID: PMC11054522 DOI: 10.3390/s24082441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 04/05/2024] [Accepted: 04/09/2024] [Indexed: 04/28/2024]
Abstract
In racehorses, the risk of musculoskeletal injury is linked to a decrease in speed and stride length (SL) over consecutive races prior to injury. Surface characteristics influence stride parameters. We hypothesized that large changes in stride parameters are found during galloping in response to dirt racetrack preparation. Harrowing of the back stretch of a half-mile dirt racetrack was altered in three individual lanes with decreasing depth from the inside to the outside. Track underlay compaction and water content were changed between days. Twelve horses (six on day 2) were sequentially galloped at a target speed of 16 ms-1 across the three lanes. Speed, stride frequency (SF), and SL were quantified with a GPS/GNSS logger. Mixed linear models with speed as covariate analyzed SF and SL, with track hardness and moisture content as fixed factors (p < 0.05). At the average speed of 16.48 ms-1, hardness (both p < 0.001) and moisture content (both p < 0.001) had significant effects on SF and SL. The largest difference in SL of 0.186 m between hardness and moisture conditions exceeded the 0.10 m longitudinal decrease over consecutive race starts previously identified as injury predictor. This suggests that detailed measurements of track conditions might be useful for refining injury prediction models.
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Affiliation(s)
- Thilo Pfau
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada; (A.S.); (W.B.E.)
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada;
| | - Olivia L. Bruce
- Department of Biomedical Engineering, Schulich School of Engineering, University of Calgary, Calgary, AB T2N 1N4, Canada;
- McCaig Institute for Bone and Joint Health, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Andrew Sawatsky
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada; (A.S.); (W.B.E.)
| | - Renaud Leguillette
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada;
| | - W. Brent Edwards
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada; (A.S.); (W.B.E.)
- Department of Biomedical Engineering, Schulich School of Engineering, University of Calgary, Calgary, AB T2N 1N4, Canada;
- McCaig Institute for Bone and Joint Health, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
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Forbes B, Ho W, Parkes RSV, Sepulveda Caviedes MF, Pfau T, Martel DR. Associations between Racing Thoroughbred Movement Asymmetries and Racing and Training Direction. Animals (Basel) 2024; 14:1086. [PMID: 38612325 PMCID: PMC11011192 DOI: 10.3390/ani14071086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 03/27/2024] [Accepted: 03/28/2024] [Indexed: 04/14/2024] Open
Abstract
BACKGROUND Racehorses commonly train and race in one direction, which may result in gait asymmetries. This study quantified gait symmetry in two cohorts of Thoroughbreds differing in their predominant exercising direction; we hypothesized that there would be significant differences in the direction of asymmetry between cohorts. METHODS 307 Thoroughbreds (156 from Singapore Turf Club (STC)-anticlockwise; 151 from Hong Kong Jockey Club (HKJC)-clockwise) were assessed during a straight-line, in-hand trot on firm ground with inertial sensors on their head and pelvis quantifying differences between the minima, maxima, upward movement amplitudes (MinDiff, MaxDiff, UpDiff), and hip hike (HHD). The presence of asymmetry (≥5 mm) was assessed for each variable. Chi-Squared tests identified differences in the number of horses with left/right-sided movement asymmetry between cohorts and mixed model analyses evaluated differences in the movement symmetry values. RESULTS HKJC had significantly more left forelimb asymmetrical horses (Head: MinDiff p < 0.0001, MaxDiff p < 0.03, UpDiff p < 0.01) than STC. Pelvis MinDiff (p = 0.010) and UpDiff (p = 0.021), and head MinDiff (p = 0.006) and UpDiff (p = 0.017) values were significantly different between cohorts; HKJC mean values indicated left fore- and hindlimb asymmetry, and STC mean values indicated right fore- and hindlimb asymmetry. CONCLUSION the asymmetry differences between cohorts suggest that horses may adapt their gait to their racing direction, with kinematics reflecting reduced 'outside' fore- and hindlimb loading.
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Affiliation(s)
- Bronte Forbes
- Hong Kong Jockey Club, Hong Kong, China; (B.F.); (W.H.)
- Singapore Turf Club, Singapore 738078, Singapore
| | - Winnie Ho
- Hong Kong Jockey Club, Hong Kong, China; (B.F.); (W.H.)
- Department of Veterinary Clinical Sciences, City University of Hong Kong, Hong Kong, China;
| | - Rebecca S. V. Parkes
- Department of Veterinary Clinical Sciences, City University of Hong Kong, Hong Kong, China;
| | | | - Thilo Pfau
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada;
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Daniel R. Martel
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada;
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Persson-Sjodin E, Hernlund E, Pfau T, Andersen PH, Forsström KH, Byström A, Serra Bragança FM, Hardeman A, Greve L, Egenvall A, Rhodin M. Withers vertical movement symmetry is useful for locating the primary lame limb in naturally occurring lameness. Equine Vet J 2024; 56:76-88. [PMID: 37226583 DOI: 10.1111/evj.13947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 05/04/2023] [Indexed: 05/26/2023]
Abstract
BACKGROUND During orthopaedic assessment of lame horses, a head nod is commonly present in both primary forelimb and hindlimb lame horses. Additional motion metrics that could assist clinicians in correctly differentiating between these two scenarios would be of great clinical value. OBJECTIVES The primary objective of this study was to examine whether withers movement asymmetry can be used in a clinical setting to distinguish primary forelimb lameness from compensatory head movement asymmetry due to primary hindlimb lameness. STUDY DESIGN Retrospective, multicentre study. METHODS Movement asymmetry of head, withers and pelvis was measured using multi-camera optical motion capture, as part of routine lameness investigations at four European equine hospitals. Vertical movement asymmetry parameters from 317 horses trotting in a straight line were compared before and after successful diagnostic analgesia of a single limb. Descriptive statistics, t-tests and linear models were used to analyse the data. RESULTS In forelimb lame horses, 80%-81% showed head and withers asymmetry both indicating lameness in the same forelimb. In hindlimb lame horses, 69%-72% showed head asymmetry ipsilateral to the lame hindlimb and withers asymmetry diagonal to the lame hindlimb, thus, head and withers asymmetry indicated lameness in different forelimbs. A large (>15 mm) compensatory head nod was seen in 28%-31% of the hindlimb lame horses. In 89%-92% of these, head and withers asymmetry indicated lameness in different forelimbs. Withers asymmetry decreased linearly with reduced head or pelvic asymmetry for both forelimb and hindlimb lame horses. MAIN LIMITATIONS Compensatory strategies were evaluated on group level to identify common patterns, potentially ignoring uncommon individual strategies. CONCLUSIONS Withers vertical movement asymmetry metrics can be useful in helping to locate the primary lame limb during quantitative lameness assessment. Head and withers movement asymmetry parameters generally indicate the same forelimb in forelimb lame horses, but different forelimbs in hindlimb lame horses.
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Affiliation(s)
- Emma Persson-Sjodin
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Elin Hernlund
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Thilo Pfau
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
- Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Pia Haubro Andersen
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Karin Holm Forsström
- Equine Clinic, University Animal Hospital, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Anna Byström
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Filipe M Serra Bragança
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Aagje Hardeman
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
- DataHorse, Wierden, The Netherlands
| | - Line Greve
- Evidensia Specialist Equine Hospital Helsingborg, Helsingborg, Sweden
| | - Agneta Egenvall
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Marie Rhodin
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
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Pfau T, Clark KS, Bolt DM, Lai JS, Perrier M, Rhodes JB, Smith RK, Fiske-Jackson A. Changes in Head and Pelvic Movement Symmetry after Diagnostic Anaesthesia: Interactions between Subjective Judgement Categories and Commonly Applied Blocks. Animals (Basel) 2023; 13:3769. [PMID: 38136806 PMCID: PMC10740945 DOI: 10.3390/ani13243769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 11/29/2023] [Accepted: 12/05/2023] [Indexed: 12/24/2023] Open
Abstract
Limited evidence is available relating gait changes to diagnostic anaesthesia. We investigated associations between specific movement patterns and diagnostic anaesthesia of different anatomical structures in a retrospective analysis. Referral-level lameness cases were included with the following criteria: presence of diagnostic anaesthesia of a forelimb and/or hind limb; subjective efficacy classified as "negative", "partially positive", or "positive"; quantitative gait data available from inertial measurement units. Gait changes were calculated for three forelimb (palmar digital, abaxial sesamoid, low 4-point nerve block) and five hind limb diagnostic blocks (tarso-metatarsal, metatarsophalangeal joint block, deep branch of lateral plantar, low 6-point, abaxial sesamoid nerve block). Mixed models (random factor "case", fixed factors "diagnostic anaesthesia type" and "efficacy", two-way interaction) assessed the head and pelvic movement (p < 0.05, Bonferroni correction). Four parameters were significantly affected by forelimb anaesthesia (N = 265) (all p ≤ 0.031) and six by hind limb anaesthesia (N = 342) efficacy (all p ≤ 0.001). All head movement parameters and pelvic push-off asymmetry were significantly affected by the two-way interaction after forelimb anaesthesia (all p ≤ 0.023) and two pelvic movement symmetry parameters by the two-way interaction after hind limb anaesthesia (all p ≤ 0.020). There are interactions between block efficacy and type resulting in changes in weight-bearing and push-off-associated head and pelvic movement symmetry after diagnostic anaesthesia.
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Affiliation(s)
- Thilo Pfau
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Kaitlyn Sophia Clark
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, Hatfield AL9 7TA, UK
| | - David M. Bolt
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, Hatfield AL9 7TA, UK
| | - Jaclyn Samantha Lai
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, Hatfield AL9 7TA, UK
| | - Melanie Perrier
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, Hatfield AL9 7TA, UK
| | - Jessica Bryce Rhodes
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, Hatfield AL9 7TA, UK
| | - Roger K. Smith
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, Hatfield AL9 7TA, UK
| | - Andrew Fiske-Jackson
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, Hatfield AL9 7TA, UK
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Pfau T, Landsbergen K, Davis BL, Kenny O, Kernot N, Rochard N, Porte-Proust M, Sparks H, Takahashi Y, Toth K, Scott WM. Comparing Inertial Measurement Units to Markerless Video Analysis for Movement Symmetry in Quarter Horses. Sensors (Basel) 2023; 23:8414. [PMID: 37896509 PMCID: PMC10610735 DOI: 10.3390/s23208414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 10/07/2023] [Accepted: 10/10/2023] [Indexed: 10/29/2023]
Abstract
BACKGROUND With an increasing number of systems for quantifying lameness-related movement asymmetry, between-system comparisons under non-laboratory conditions are important for multi-centre or referral-level studies. This study compares an artificial intelligence video app to a validated inertial measurement unit (IMU) gait analysis system in a specific group of horses. METHODS Twenty-two reining Quarter horses were equipped with nine body-mounted IMUs while being videoed with a smartphone app. Both systems quantified head and pelvic movement symmetry during in-hand trot (hard/soft ground) and on the lunge (left/right rein, soft ground). Proportional limits of agreement (pLoA) were established. RESULTS Widths of pLoA were larger for head movement (29% to 50% in-hand; 22% to 38% on lunge) than for pelvic movement (13% to 24% in-hand; 14% to 24% on lunge). CONCLUSION The between-system pLoAs exceed current "lameness thresholds" aimed at identifying the affected limb(s) in lame horses. They also exceed published limits of agreement for stride-matched data but are similar to repeatability values and "lameness thresholds" from "non-lame" horses. This is encouraging for multi-centre studies and referral-level veterinary practice. The narrower pLoA values for pelvic movement asymmetry are particularly encouraging, given the difficulty of grading hind limb lameness "by eye".
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Affiliation(s)
- Thilo Pfau
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada (W.M.S.)
| | - Kiki Landsbergen
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada (W.M.S.)
| | - Brittany L. Davis
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Olivia Kenny
- Faculty of Biomedical Engineering, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Nicole Kernot
- School of Agricultural, Environmental and Veterinary Sciences, Charles Sturt University, North Wagga, NSW 2650, Australia
| | - Nina Rochard
- Ecole Nationale Vétérinaire de Toulouse, 31300 Toulouse, France
| | | | - Holly Sparks
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada (W.M.S.)
| | - Yuji Takahashi
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada
- Japan Racing Association, Tokyo 105-0003, Japan
| | - Kasara Toth
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada (W.M.S.)
| | - W. Michael Scott
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada (W.M.S.)
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Turner A, Masters N, Pfau T, Hutchinson JR, Weller R. DEVELOPMENT AND EVALUATION OF A STANDARDIZED SYSTEM FOR THE ASSESSMENT OF LOCOMOTOR HEALTH IN ELEPHANTS UNDER HUMAN CARE. J Zoo Wildl Med 2023; 54:529-537. [PMID: 37817618 DOI: 10.1638/2022-0110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/18/2023] [Indexed: 10/12/2023] Open
Abstract
Although lameness is a common problem in elephants (Asian elephant [Elephas maximus] and African elephants Loxodonta africana and Loxodonta cyclotis) under human care, there has not been a standardized lameness assessment system to date. This study developed and evaluated a standardized system for the assessment of locomotion in elephants under human care regardless of husbandry system. In total, 72 elephants out of a possible 73 in the United Kingdom and Ireland were filmed from behind, from in front, and from both sides. Using a questionnaire and a select panel of elephant specialists, a zoo veterinarian, and a locomotion expert, a numerical rating scoring (NRS) system was proposed. Locomotion was scored on a 4-point scale with numerical values 0-4 corresponding to specific criteria as follows: 0 = clinically sound, 1 = stiffness, 2 = abnormal tracking, and 4 = reluctance to bear weight. The intra- and interobserver repeatability of five veterinary surgeons using this system was determined and compared with a visual analog scale (VAS) expressed as a 100-mm line. Overall intraobserver reliability was moderate (Cohen's kappa [κ] = 0.676) and interobserver reliability was fair (κ = 0.37) for the presence of lameness. Interobserver agreement improved from the first scoring to second scoring from slight agreement to fair agreement for stiffness and reluctance to bear weight. Abnormal tracking had moderate intraobserver agreement for both scoring sessions. There were wide widths of agreement for the VAS interobserver (67 mm); however, they were narrower for the intraobserver (33 mm). The developed NRS can be used on freely moving elephants to evaluate elephant locomotion, regardless of husbandry methods, and has been shown to be more reliable than a VAS.
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Affiliation(s)
- Abigail Turner
- Royal Veterinary College, Hatfield, AL9 7TA, United Kingdom,
| | - Nic Masters
- Veterinary Department, ZSL Whipsnade Zoo, Dunstable, Bedfordshire, LU6 2LF, United Kingdom
| | - Thilo Pfau
- Royal Veterinary College, Hatfield, AL9 7TA, United Kingdom
| | | | - Renate Weller
- Royal Veterinary College, Hatfield, AL9 7TA, United Kingdom
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Horan K, Price H, Day P, Mackechnie-Guire R, Pfau T. Timing Differences in Stride Cycle Phases in Retired Racehorses Ridden in Rising and Two-Point Seat Positions at Trot on Turf, Artificial and Tarmac Surfaces. Animals (Basel) 2023; 13:2563. [PMID: 37627354 PMCID: PMC10451298 DOI: 10.3390/ani13162563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/24/2023] [Accepted: 08/05/2023] [Indexed: 08/27/2023] Open
Abstract
Injuries to racehorses and their jockeys are not limited to the racetrack and high-speed work. To optimise racehorse-jockey dyads' health, well-being, and safety, it is important to understand their kinematics under the various exercise conditions they are exposed to. This includes trot work on roads, turf and artificial surfaces when accessing gallop tracks and warming up. This study quantified the forelimb hoof kinematics of racehorses trotting over tarmac, turf and artificial surfaces as their jockey adopted rising and two-point seat positions. A convenience sample of six horses was recruited from the British Racing School, Newmarket, and the horses were all ridden by the same jockey. Inertial measurement units (HoofBeat) were secured to the forelimb hooves of the horses and enabled landing, mid-stance, breakover, swing and stride durations, plus stride length, to be quantified via an in-built algorithm. Data were collected at a frequency of 1140 Hz. Linear Mixed Models were used to test for significant differences in the timing of these stride phases and stride length amongst the different surface and jockey positions. Speed was included as a covariate. Significance was set at p < 0.05. Hoof landing and mid-stance durations were negatively correlated, with approximately a 0.5 ms decrease in mid-stance duration for every 1 ms increase in landing duration (r2 = 0.5, p < 0.001). Hoof landing duration was significantly affected by surface (p < 0.001) and an interaction between jockey position and surface (p = 0.035). Landing duration was approximately 4.4 times shorter on tarmac compared to grass and artificial surfaces. Mid-stance duration was significantly affected by jockey position (p < 0.001) and surface (p = 0.001), speed (p < 0.001) and jockey position*speed (p < 0.001). Mean values for mid-stance increased by 13 ms with the jockey in the two-point seat position, and mid-stance was 19 ms longer on the tarmac than on the artificial surface. There was no significant difference in the breakover duration amongst surfaces or jockey positions (p ≥ 0.076) for the ridden dataset. However, the mean breakover duration on tarmac in the presence of a rider decreased by 21 ms compared to the in-hand dataset. Swing was significantly affected by surface (p = 0.039) and speed (p = 0.001), with a mean swing phase 20 ms longer on turf than on the artificial surface. Total stride duration was affected by surface only (p = 0.011). Tarmac was associated with a mean stride time that was significantly reduced, by 49 ms, compared to the turf, and this effect may be related to the shorter landing times on turf. Mean stride length was 14 cm shorter on tarmac than on grass, and stride length showed a strong positive correlation with speed, with a 71 cm increase in stride length for every 1 m s-1 increase in speed (r2 = 0.8, p < 0.001). In summary, this study demonstrated that the durations of the different stride cycle phases and stride length can be sensitive to surface type and jockey riding position. Further work is required to establish links between altered stride time variables and the risk of musculoskeletal injury.
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Affiliation(s)
- Kate Horan
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, Brookmans Park AL9 7TA, Hertfordshire, UK;
| | - Haydn Price
- Little Pastures, Gwehelog, Usk NP15 1RD, Gwent, UK;
| | - Peter Day
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, Brookmans Park AL9 7TA, Hertfordshire, UK;
| | | | - Thilo Pfau
- Faculties of Kinesiology and Veterinary Medicine, University of Calgary, 2500 University Dr NW, Calgary, AB T2N 1N4, Canada;
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10
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Pfau T, Bruce O, Brent Edwards W, Leguillette R. Stride frequency derived from GPS speed fluctuations in galloping horses. J Biomech 2022; 145:111364. [PMID: 36343415 DOI: 10.1016/j.jbiomech.2022.111364] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 10/10/2022] [Accepted: 10/27/2022] [Indexed: 11/06/2022]
Abstract
Changes in gallop stride parameters prior to injury have been documented previously in Thoroughbred racehorses. Validating solutions for quantification of fundamental stride parameters is important for large scale studies investigating injury related factors. This study describes a fast Fourier transformation-based method for extracting stride frequency (SF) values from speed fluctuations recorded with a standalone GPS-logger suitable for galloping horses. Limits of agreement with SF values derived from inertial measurement unit (IMU) pitch data are presented. Twelve Thoroughbred horses were instrumented with a GPS-logger (Vbox sport, Racelogic, 10 Hz samplerate) and a IMU-logger (Xsens DOT, Xsens, 120 Hz samplerate), both attached to the saddlecloth in the midline caudal to the saddle and time synchronized by minimizing root mean square error between differentiated GPS and IMU heading. Each horse performed three gallop trials with a target speed of 36miles per hour (16.1 ms-1) on a dirt racetrack. Average speed was 16.48 ms-1 ranging from 16.1 to 17.4 ms-1 between horses. Limits of agreement between GPS- and IMU-derived SF had a bias of 0.0032 Hz and a sample-by-sample precision of +/-0.027 Hz calculated over N = 2196 values. The stride length uncertainty related to the trial-by-trial SF precision of 0.0091 Hz achieved across 100 m gallop sections is smaller than the 10 cm decrease in stride length that has been associated with an increased risk of musculoskeletal injury. This suggests that the described method is suitable for calculating fundamental stride parameters in the context of injury prevention in galloping horses.
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Affiliation(s)
- Thilo Pfau
- Faculty of Kinesiology, University of Calgary, 2500 University Dr NW, Calgary T2N 1N4, Alberta, Canada; Faculty of Veterinary Medicine, University of Calgary, 2500 University Dr NW, Calgary T2N 1N4, Alberta, Canada.
| | - Olivia Bruce
- Department of Biomedical Engineering, Schulich School of Engineering, University of Calgary, 2500 University Dr NW, Calgary T2N 1N4, Alberta, Canada; McCaig Institute for Bone and Joint Health, Cumming School of Medicine, University of Calgary, 2500 University Dr NW, Calgary T2N 1N4, Alberta, Canada
| | - W Brent Edwards
- Faculty of Kinesiology, University of Calgary, 2500 University Dr NW, Calgary T2N 1N4, Alberta, Canada; Department of Biomedical Engineering, Schulich School of Engineering, University of Calgary, 2500 University Dr NW, Calgary T2N 1N4, Alberta, Canada; McCaig Institute for Bone and Joint Health, Cumming School of Medicine, University of Calgary, 2500 University Dr NW, Calgary T2N 1N4, Alberta, Canada
| | - Renaud Leguillette
- Faculty of Veterinary Medicine, University of Calgary, 2500 University Dr NW, Calgary T2N 1N4, Alberta, Canada
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Rhodin M, Smit IH, Persson-Sjodin E, Pfau T, Gunnarsson V, Björnsdóttir S, Zetterberg E, Clayton HM, Hobbs SJ, Serra Bragança F, Hernlund E. Timing of Vertical Head, Withers and Pelvis Movements Relative to the Footfalls in Different Equine Gaits and Breeds. Animals (Basel) 2022; 12:ani12213053. [PMID: 36359178 PMCID: PMC9657284 DOI: 10.3390/ani12213053] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 10/31/2022] [Accepted: 10/31/2022] [Indexed: 11/09/2022] Open
Abstract
Simple Summary Movement symmetry of the head and pelvis are used to measure lameness in horses in trot. Although head, pelvis and limb movements have been described, less is known about the temporal relationships between them. This information is needed to understand how the movements change with lameness. This is particularly relevant in gaited horses, such as the Icelandic horse that perform gaits such as tölt and pace, which are challenging to evaluate. This study used inertial measurement units to investigate head, withers and pelvis motion relative to limb movements in Icelandic, Warmblood and Iberian horses. Limb movements, together with vertical movements and lowest/highest positions of the head, withers and pelvis were calculated, and the relative timing of the events was compared across breeds. Additionally, data for tölt and pace were collected and evaluated in ridden Icelandic horses. For all gaits except walk and pace, the lowest/highest positions of the head/withers/pelvis were closely temporally related to midstance and hoof-off, respectively. Pelvic and withers total range of motion differed between all breeds. The Icelandic horses showed shorter stride duration and smaller movements of the upper body than the other breeds at trot, which may explain why lameness evaluation in this breed is challenging. Abstract Knowledge of vertical motion patterns of the axial body segments is a prerequisite for the development of algorithms used in automated detection of lameness. To date, the focus has been on the trot. This study investigates the temporal synchronization between vertical motion of the axial body segments with limb kinematic events in walk and trot across three popular types of sport horses (19 Warmbloods, 23 Iberians, 26 Icelandics) that are known to have different stride kinematics, and it presents novel data describing vertical motion of the axial body segments in tölting and pacing Icelandic horses. Inertial measurement unit sensors recorded limb kinematics, vertical motion of the axial body at all symmetrical gaits that the horse could perform (walk, trot, tölt, pace). Limb kinematics, vertical range of motion and lowest/highest positions of the head, withers and pelvis were calculated. For all gaits except walk and pace, lowest/highest positions of the pelvis and withers were found to be closely related temporally to midstance and start of suspension of the hind/fore quarter, respectively. There were differences in pelvic/withers range of motion between all breeds where the Icelandic horses showed the smallest motion, which may explain why lameness evaluation in this breed is challenging.
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Affiliation(s)
- Marie Rhodin
- Department of Anatomy Physiology and Biochemistry, Swedish University of Agricultural Sciences, S-750 07 Uppsala, Sweden
- Correspondence: ; Tel.: +461-867-2194
| | - Ineke H. Smit
- Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 112-114, NL-3584 CM Utrecht, The Netherlands
| | - Emma Persson-Sjodin
- Department of Anatomy Physiology and Biochemistry, Swedish University of Agricultural Sciences, S-750 07 Uppsala, Sweden
| | - Thilo Pfau
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | | | - Sigridur Björnsdóttir
- Faculty of Agricultural Sciences, Agricultural University of Iceland, 311 Hvanneyri, Iceland
| | - Ebba Zetterberg
- Department of Anatomy Physiology and Biochemistry, Swedish University of Agricultural Sciences, S-750 07 Uppsala, Sweden
| | | | - Sarah J. Hobbs
- Research Centre for Applied Sport, Physical Activity and Performance, University of Central Lancashire, Preston PR1 2HE, UK
| | - Filipe Serra Bragança
- Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 112-114, NL-3584 CM Utrecht, The Netherlands
| | - Elin Hernlund
- Department of Anatomy Physiology and Biochemistry, Swedish University of Agricultural Sciences, S-750 07 Uppsala, Sweden
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12
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Marunova E, Hoenecke K, Fiske-Jackson A, Smith RK, Bolt DM, Perrier M, Gerdes C, Hernlund E, Rhodin M, Pfau T. Changes in Head, Withers, and Pelvis Movement Asymmetry in Lame Horses as a Function of Diagnostic Anesthesia Outcome, Surface and Direction. J Equine Vet Sci 2022; 118:104136. [DOI: 10.1016/j.jevs.2022.104136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 09/20/2022] [Accepted: 09/30/2022] [Indexed: 11/08/2022]
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Pfau T, Bolt DM, Fiske-Jackson A, Gerdes C, Hoenecke K, Lynch L, Perrier M, Smith RKW. Linear Discriminant Analysis for Investigating Differences in Upper Body Movement Symmetry in Horses before/after Diagnostic Analgesia in Relation to Expert Judgement. Animals (Basel) 2022; 12:ani12060762. [PMID: 35327159 PMCID: PMC8944550 DOI: 10.3390/ani12060762] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 03/14/2022] [Accepted: 03/16/2022] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Identifying the anatomical structures involved in causing pain and an associated lameness in a horse typically requires assessment in straight lines and circles and using regional administration of local anesthetic drugs (diagnostic analgesia). Visual assessment of changes in movement are affected by bias, i.e., expected changes influence decisions. Quantitative measurements with inertial sensors aim at removing this bias. The current study is aimed at investigating how a specific data-driven method, linear discriminant analysis (LDA), may be useful for aiding veterinary decision making about perceived changes in lameness. Changes in movement data after diagnostic analgesia and expert judgements from 53 lame horses were used to study (a) the accuracy of LDA-based decision making, (b) differences between straight-line and circular movement and (c) which commonly used movement features are most useful in this context. Accuracy was comparatively low and varied considerably between 36% and 57%, indicating considerable overlap between movement symmetry data of the diagnostic analgesia categories. The best data-driven separation between categories was observed when the limb in which perineural anaesthesia had been performed was on the inside of the circle (on hard ground for forelimb and on soft ground for hindlimb diagnostic analgesia). Movement features of all three landmarks (head, withers, pelvis) were important for data-driven classification, emphasizing the complexity of the movement pattern changes after diagnostic analgesia observed in lame horses. Abstract Diagnostic analgesia and lunging are parts of the equine lameness examination, aiding veterinarians in localizing the anatomical region(s) causing pain-related movement deficits. Expectation bias of visual assessment and complex movement asymmetry changes in lame horses on the lunge highlight the need to investigate data-driven approaches for optimally integrating quantitative gait data into veterinary decision-making to remove bias. A retrospective analysis was conducted with inertial sensor movement symmetry data before/after diagnostic analgesia relative to subjective judgement of efficacy of diagnostic analgesia in 53 horses. Horses were trotted on the straight and on the lunge. Linear discriminant analysis (LDA) applied to ten movement asymmetry features quantified the accuracy of classifying negative, partial and complete responses to diagnostic analgesia and investigated the influence of movement direction and surface type on the quality of the data-driven separation between diagnostic analgesia categories. The contribution of movement asymmetry features to decision-making was also studied. Leave-one-out classification accuracy varied considerably (38.3–57.4% for forelimb and 36.1–56.1% for hindlimb diagnostic analgesia). The highest inter-category distances (best separation) were found with the blocked limb on the inside of the circle, on hard ground for forelimb diagnostic analgesia and on soft ground for hindlimb diagnostic analgesia. These exercises deserve special attention when consulting quantitative gait data in lame horses. Head and pelvic upward movement and withers minimum differences were the features with the highest weighting within the first canonical LDA function across exercises and forelimb and hindlimb diagnostic analgesia. This highlights that movement changes after diagnostic analgesia affect the whole upper body. Classification accuracies based on quantitative movement asymmetry changes indicate considerable overlap between subjective diagnostic analgesia categories.
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Affiliation(s)
- Thilo Pfau
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield AL9 7TA, UK; (D.M.B.); (A.F.-J.); (K.H.); (L.L.); (M.P.); (R.K.W.S.)
- Faculty of Veterinary Medicine, University of Calgary, 2500 University Dr NW, Calgary, AB T2N 1N4, Canada
- Faculty of Kinesiology, University of Calgary, 2500 University Dr NW, Calgary, AB T2N 1N4, Canada
- Correspondence:
| | - David M. Bolt
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield AL9 7TA, UK; (D.M.B.); (A.F.-J.); (K.H.); (L.L.); (M.P.); (R.K.W.S.)
| | - Andrew Fiske-Jackson
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield AL9 7TA, UK; (D.M.B.); (A.F.-J.); (K.H.); (L.L.); (M.P.); (R.K.W.S.)
| | | | - Karl Hoenecke
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield AL9 7TA, UK; (D.M.B.); (A.F.-J.); (K.H.); (L.L.); (M.P.); (R.K.W.S.)
| | - Lucy Lynch
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield AL9 7TA, UK; (D.M.B.); (A.F.-J.); (K.H.); (L.L.); (M.P.); (R.K.W.S.)
| | - Melanie Perrier
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield AL9 7TA, UK; (D.M.B.); (A.F.-J.); (K.H.); (L.L.); (M.P.); (R.K.W.S.)
| | - Roger K. W. Smith
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield AL9 7TA, UK; (D.M.B.); (A.F.-J.); (K.H.); (L.L.); (M.P.); (R.K.W.S.)
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14
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Pfau T, Scott WM, Sternberg Allen T. Upper Body Movement Symmetry in Reining Quarter Horses during Trot In-Hand, on the Lunge and during Ridden Exercise. Animals (Basel) 2022; 12:ani12050596. [PMID: 35268165 PMCID: PMC8909210 DOI: 10.3390/ani12050596] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 02/22/2022] [Accepted: 02/25/2022] [Indexed: 12/20/2022] Open
Abstract
Veterinary lameness examinations often comprise assessing ridden horses. Quantitative movement symmetry measurements can aid evidence-based decision making. While these are available for ‘English’ style riding, they are not for ‘Western’ style riding. This quantitative observational study quantified movement symmetry in reining Quarter Horses (QHs). Movement symmetry of the head, withers and sacrum (differences between minima, maxima and upward amplitudes) were quantified with inertial sensors in N = 30 medium/high level reining QHs during trot in-hand, on the lunge and ridden by one experienced rider (straight-line/circles) on reining-purpose riding surfaces. Mixed linear models for movement symmetry assessed the effects of ridden exercise and movement direction (fixed factors), stride time (covariate) and horse (random factor): single factors and two-way interactions with Bonferroni correction at p < 0.05. Three withers and pelvic parameters showed marginally more symmetrical movement when ridden (p ≤ 0.044; 1−5 mm differences). Three withers, three sacrum and one head parameter were significantly affected by movement direction (all p ≤ 0.026), five showed increased asymmetry on the inside rein, and two, quantifying vertical displacement maximum difference, showed the opposite. Riding QHs in ‘Western’ style showed small movement symmetry differences. Circular exercise confirmed increases in weight bearing asymmetry on the inside rein and in pushoff asymmetry on the outside rein. This should be further investigated for differentiating between different causes of lameness.
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Affiliation(s)
- Thilo Pfau
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield AL9 7TA, UK;
- Faculty of Veterinary Medicine, University of Calgary, 2500 University Dr NW, Calgary, AB T2N 1N4, Canada;
- Faculty of Kinesiology, University of Calgary, 2500 University Dr NW, Calgary, AB T2N 1N4, Canada
- Correspondence:
| | - W. Michael Scott
- Faculty of Veterinary Medicine, University of Calgary, 2500 University Dr NW, Calgary, AB T2N 1N4, Canada;
| | - Tabitha Sternberg Allen
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield AL9 7TA, UK;
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15
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Horan K, Kourdache K, Coburn J, Day P, Carnall H, Harborne D, Brinkley L, Hammond L, Millard S, Lancaster B, Pfau T. The effect of horseshoes and surfaces on horse and jockey centre of mass displacements at gallop. PLoS One 2021; 16:e0257820. [PMID: 34813584 PMCID: PMC8610270 DOI: 10.1371/journal.pone.0257820] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 09/12/2021] [Indexed: 11/18/2022] Open
Abstract
Horseshoes influence how horses' hooves interact with different ground surfaces, during the impact, loading and push-off phases of a stride cycle. Consequently, they impact on the biomechanics of horses' proximal limb segments and upper body. By implication, different shoe and surface combinations could drive changes in the magnitude and stability of movement patterns in horse-jockey dyads. This study aimed to quantify centre of mass (COM) displacements in horse-jockey dyads galloping on turf and artificial tracks in four shoeing conditions: 1) aluminium; 2) barefoot; 3) GluShu; and 4) steel. Thirteen retired racehorses and two jockeys at the British Racing School were recruited for this intervention study. Tri-axial acceleration data were collected close to the COM for the horse (girth) and jockey (kidney-belt), using iPhones (Apple Inc.) equipped with an iOS app (SensorLog, sample rate = 50 Hz). Shoe-surface combinations were tested in a randomized order and horse-jockey pairings remained constant. Tri-axial acceleration data from gallop runs were filtered using bandpass Butterworth filters with cut-off frequencies of 15 Hz and 1 Hz, then integrated for displacement using Matlab. Peak displacement was assessed in both directions (positive 'maxima', negative 'minima') along the cranio-caudal (CC, positive = forwards), medio-lateral (ML, positive = right) and dorso-ventral (DV, positive = up) axes for all strides with frequency ≥2 Hz (mean = 2.06 Hz). Linear mixed-models determined whether surfaces, shoes or shoe-surface interactions (fixed factors) significantly affected the displacement patterns observed, with day, run and horse-jockey pairs included as random factors; significance was set at p<0.05. Data indicated that surface-type significantly affected peak COM displacements in all directions for the horse (p<0.0005) and for all directions (p≤0.008) but forwards in the jockey. The largest differences were observed in the DV-axis, with an additional 5.7 mm and 2.5 mm of downwards displacement for the horse and jockey, respectively, on the artificial surface. Shoeing condition significantly affected all displacement parameters except ML-axis minima for the horse (p≤0.007), and all displacement parameters for the jockey (p<0.0005). Absolute differences were again largest vertically, with notable similarities amongst displacements from barefoot and aluminium trials compared to GluShu and steel. Shoe-surface interactions affected all but CC-axis minima for the jockey (p≤0.002), but only the ML-axis minima and maxima and DV-axis maxima for the horse (p≤0.008). The results support the idea that hoof-surface interface interventions can significantly affect horse and jockey upper-body displacements. Greater sink of hooves on impact, combined with increased push-off during the propulsive phase, could explain the higher vertical displacements on the artificial track. Variations in distal limb mass associated with shoe-type may drive compensatory COM displacements to minimize the energetic cost of movement. The artificial surface and steel shoes provoked the least CC-axis movement of the jockey, so may promote greatest stability. However, differences between horse and jockey mean displacements indicated DV-axis and CC-axis offsets with compensatory increases and decreases, suggesting the dyad might operate within displacement limits to maintain stability. Further work is needed to relate COM displacements to hoof kinematics and to determine whether there is an optimum configuration of COM displacement to optimise performance and minimise injury.
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Affiliation(s)
- Kate Horan
- The Royal Veterinary College, Hatfield, Hertfordshire, United Kingdom
- The Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Easter Bush Campus, Midlothian, United Kingdom
- * E-mail:
| | | | - James Coburn
- James Coburn AWCF Farriers Ltd, Newmarket, United Kingdom
| | - Peter Day
- The Royal Veterinary College, Hatfield, Hertfordshire, United Kingdom
| | - Henry Carnall
- James Coburn AWCF Farriers Ltd, Newmarket, United Kingdom
| | - Dan Harborne
- James Coburn AWCF Farriers Ltd, Newmarket, United Kingdom
| | - Liam Brinkley
- James Coburn AWCF Farriers Ltd, Newmarket, United Kingdom
| | - Lucy Hammond
- The British Racing School, Newmarket, United Kingdom
| | - Sean Millard
- The Royal Veterinary College, Hatfield, Hertfordshire, United Kingdom
| | - Bryony Lancaster
- The Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Easter Bush Campus, Midlothian, United Kingdom
| | - Thilo Pfau
- The Royal Veterinary College, Hatfield, Hertfordshire, United Kingdom
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16
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Hertkorn J, Schmidt JN, Guo M, Böttcher F, Ng KSH, Graham SD, Uerlings P, Büchler HP, Langen T, Zwierlein M, Pfau T. Supersolidity in Two-Dimensional Trapped Dipolar Droplet Arrays. Phys Rev Lett 2021; 127:155301. [PMID: 34678009 DOI: 10.1103/physrevlett.127.155301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 09/03/2021] [Indexed: 06/13/2023]
Abstract
We theoretically investigate the ground states and the spectrum of elementary excitations across the superfluid to droplet crystallization transition of an oblate dipolar Bose-Einstein condensate. We systematically identify regimes where spontaneous rotational symmetry breaking leads to the emergence of a supersolid phase with characteristic collective excitations, such as the Higgs amplitude mode. Furthermore, we study the dynamics across the transition and show how these supersolids can be realized with standard protocols in state-of-the-art experiments.
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Affiliation(s)
- J Hertkorn
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - J-N Schmidt
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - M Guo
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - F Böttcher
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - K S H Ng
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - S D Graham
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - P Uerlings
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - H P Büchler
- Institute for Theoretical Physics III and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Langen
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - M Zwierlein
- MIT-Harvard Center for Ultracold Atoms, Research Laboratory of Electronics, and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - T Pfau
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
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17
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Horan K, Coburn J, Kourdache K, Day P, Harborne D, Brinkley L, Carnall H, Hammond L, Peterson M, Millard S, Pfau T. Influence of Speed, Ground Surface and Shoeing Condition on Hoof Breakover Duration in Galloping Thoroughbred Racehorses. Animals (Basel) 2021; 11:ani11092588. [PMID: 34573553 PMCID: PMC8472780 DOI: 10.3390/ani11092588] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 08/30/2021] [Accepted: 08/31/2021] [Indexed: 11/17/2022] Open
Abstract
Simple Summary In the stride cycle of a horse, there is a period of time when the hoof pushes off from the ground surface and rotates through an angle of approximately 90 degrees before it is lifted off. This time period is known as hoof breakover. Using slow-motion video footage, this study measured breakover duration in retired Thoroughbred racehorses galloping at a range of speeds on two surfaces (artificial and turf) in four shoeing conditions (aluminium, barefoot, GluShu and steel). Hooves from different limbs were assessed separately in this asymmetric gait. Increasing speed was correlated with decreasing breakover duration, and this trend was more enhanced in the hindlimbs than in the forelimbs at high gallop speeds. Breakover duration was faster on the artificial surface compared to the turf surface for all limbs, under the ground conditions studied. The first limb to contact the ground surface after the suspension phase (the ‘non-leading’ hindlimb), was additionally influenced by shoeing condition and an interaction that occurred between shoeing condition and speed. Determining parameters that alter breakover duration will be important for lowering the risk of musculo-skeletal injuries, optimising gait quality and improving performance in galloping racehorses during both training and racing. Abstract Understanding the effect of horseshoe–surface combinations on hoof kinematics at gallop is relevant for optimising performance and minimising injury in racehorse–jockey dyads. This intervention study assessed hoof breakover duration in Thoroughbred ex-racehorses from the British Racing School galloping on turf and artificial tracks in four shoeing conditions: aluminium, barefoot, aluminium–rubber composite (GluShu) and steel. Shoe–surface combinations were tested in a randomized order and horse–jockey pairings (n = 14) remained constant. High-speed video cameras (Sony DSC-RX100M5) filmed the hoof-ground interactions at 1000 frames per second. The time taken for a hoof marker wand fixed to the lateral hoof wall to rotate through an angle of 90 degrees during 384 breakover events was quantified using Tracker software. Data were collected for leading and non-leading forelimbs and hindlimbs, at gallop speeds ranging from 23–56 km h−1. Linear mixed-models assessed whether speed, surface, shoeing condition and any interaction between these parameters (fixed factors) significantly affected breakover duration. Day and horse–jockey pair were included as random factors and speed was included as a covariate. The significance threshold was set at p < 0.05. For all limbs, breakover times decreased as gallop speed increased (p < 0.0005), although a greater relative reduction in breakover duration for hindlimbs was apparent beyond approximately 45 km h−1. Breakover duration was longer on turf compared to the artificial surface (p ≤ 0.04). In the non-leading hindlimb only, breakover duration was affected by shoeing condition (p = 0.025) and an interaction between shoeing condition and speed (p = 0.023). This work demonstrates that speed, ground surface and shoeing condition are important factors influencing the galloping gait of the Thoroughbred racehorse.
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Affiliation(s)
- Kate Horan
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, Brookmans Park, Hertfordshire AL9 7TA, UK; (P.D.); (S.M.); (T.P.)
- Correspondence:
| | - James Coburn
- James Coburn AWCF Ltd., 14 Church Lane Close, Barton Mills, Bury St Edmunds IP38 6AX, UK; (J.C.); (D.H.); (L.B.); (H.C.)
| | - Kieran Kourdache
- The British Racing School, Snailwell Road, Newmarket CB8 7NU, UK; (K.K.); (L.H.)
| | - Peter Day
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, Brookmans Park, Hertfordshire AL9 7TA, UK; (P.D.); (S.M.); (T.P.)
| | - Dan Harborne
- James Coburn AWCF Ltd., 14 Church Lane Close, Barton Mills, Bury St Edmunds IP38 6AX, UK; (J.C.); (D.H.); (L.B.); (H.C.)
| | - Liam Brinkley
- James Coburn AWCF Ltd., 14 Church Lane Close, Barton Mills, Bury St Edmunds IP38 6AX, UK; (J.C.); (D.H.); (L.B.); (H.C.)
| | - Henry Carnall
- James Coburn AWCF Ltd., 14 Church Lane Close, Barton Mills, Bury St Edmunds IP38 6AX, UK; (J.C.); (D.H.); (L.B.); (H.C.)
| | - Lucy Hammond
- The British Racing School, Snailwell Road, Newmarket CB8 7NU, UK; (K.K.); (L.H.)
| | - Mick Peterson
- Biosystems and Agricultural Engineering, University of Kentucky, Lexington, KY 40506-0503, USA;
| | - Sean Millard
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, Brookmans Park, Hertfordshire AL9 7TA, UK; (P.D.); (S.M.); (T.P.)
| | - Thilo Pfau
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, Brookmans Park, Hertfordshire AL9 7TA, UK; (P.D.); (S.M.); (T.P.)
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Cameron A, Longland A, Pfau T, Pinnegar S, Brackston I, Hockenhull J, Harris PA, Menzies-Gow NJ. The Effect of Strip Grazing on Physical Activity and Behavior in Ponies. J Equine Vet Sci 2021; 110:103745. [PMID: 34972031 DOI: 10.1016/j.jevs.2021.103745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 08/11/2021] [Accepted: 08/13/2021] [Indexed: 11/30/2022]
Abstract
This work aimed to determine the effect of strip grazing on physical activity in ponies using behavioral observations alongside accelerometers positioned at the poll. In study one, ten British native breed ponies were randomly assigned to paddock A (50 × 110 m) or B (50 × 110 m divided into seven equal strips with access to one additional strip per day) for seven days (n = 5/paddock). In study two, ten different British native breed ponies were randomly assigned for 14 days individually to (1) a control field where the animal was allowed complete access to their allotted area (n = 4); (2) a field that increased in size daily by moving a lead fence (n = 2); and (3) a field that was strip grazed using lead and back fences moved the same distance daily (n = 4). Accelerometer data were sorted into twenty-four-hour periods; each 10-second epoch was categorized as standing, grazing or locomoting using previously validated cut-off points; and time spent in each category for each day calculated. Behavioral monitoring was undertaken by direct observation on days 12-14 (study two only). Accelerometer and behavioral data were compared between grazing methods within each study. Strip grazing had no significant effect on the time spent in each physical activity category in either study. Behavioral observation revealed all ponies spent most time grazing ≤4 hours after fence moving and strip grazed ponies spent significantly more time grazing the newly available grass than elsewhere. Thus, strip grazing did not alter physical activity in ponies, but did result in preferential grazing of new grass.
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Affiliation(s)
- Amelia Cameron
- Animal Welfare and Behavior Group, Bristol Vet School, University of Bristol, Bristol, UK
| | | | | | | | | | - Joanna Hockenhull
- Animal Welfare and Behavior Group, Bristol Vet School, University of Bristol, Bristol, UK
| | | | - Nicola J Menzies-Gow
- Animal Welfare and Behavior Group, Bristol Vet School, University of Bristol, Bristol, UK.
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19
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Pfau T, Persson-Sjodin E, Gardner H, Orssten O, Hernlund E, Rhodin M. Effect of Speed and Surface Type on Individual Rein and Combined Left-Right Circle Movement Asymmetry in Horses on the Lunge. Front Vet Sci 2021; 8:692031. [PMID: 34322537 PMCID: PMC8311175 DOI: 10.3389/fvets.2021.692031] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 05/27/2021] [Indexed: 11/13/2022] Open
Abstract
Differences in movement asymmetry between surfaces and with increasing speed increase the complexity of incorporating gait analysis measurements from lunging into clinical decision making. This observational study sets out to quantify by means of quantitative gait analysis the influence of surface and speed on individual-rein movement asymmetry measurements and their averages across reins (average-rein measurements). Head, withers, and pelvic movement asymmetry was quantified in 27 horses, identified previously as presenting with considerable movement asymmetries on the straight, during trot in hand and on the lunge on two surfaces at two speeds. Mixed linear models (p < 0.05) with horse as the random factor and surface and speed category (and direction) as fixed factors analyzed the effects on 11 individual-rein and average-rein asymmetry measures. Limits of agreement quantified differences between individual-rein and average-rein measurements. A higher number of individual-rein asymmetry variables-particularly when the limb that contributed to movement asymmetry on the straight was on the inside of the circle-were affected by speed (nine variables, all p ≤ 0.047) and surface (three variables, all p ≤ 0.037) compared with average-rein asymmetry variables (two for speed, all p ≤ 0.003; two for surface, all p ≤ 0.046). Six variables were significantly different between straight-line and average-rein assessments (all p ≤ 0.031), and asymmetry values were smaller for average-rein assessments. Limits of agreement bias varied between +0.4 and +4.0 mm with standard deviations between 3.2 and 12.9 mm. Fewer average-rein variables were affected by speed highlighting the benefit of comparing left and right rein measurements. Only one asymmetry variable showed a surface difference for individual-rein and average-rein data, emphasizing the benefit of assessing surface differences on each rein individually. Variability in straight-line vs. average-rein measurements across horses and exercise conditions highlight the potential for average-rein measurements during the diagnostic process; further studies after diagnostic analgesia are needed.
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Affiliation(s)
- Thilo Pfau
- Department of Clinical Science and Services, The Royal Veterinary College, London, United Kingdom
| | - Emma Persson-Sjodin
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Harriet Gardner
- Department of Clinical Science and Services, The Royal Veterinary College, London, United Kingdom
| | - Olivia Orssten
- Department of Clinical Science and Services, The Royal Veterinary College, London, United Kingdom
| | - Elin Hernlund
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Marie Rhodin
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
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20
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Schmidt JN, Hertkorn J, Guo M, Böttcher F, Schmidt M, Ng KSH, Graham SD, Langen T, Zwierlein M, Pfau T. Roton Excitations in an Oblate Dipolar Quantum Gas. Phys Rev Lett 2021; 126:193002. [PMID: 34047619 DOI: 10.1103/physrevlett.126.193002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 04/02/2021] [Indexed: 06/12/2023]
Abstract
We observe signatures of radial and angular roton excitations around a droplet crystallization transition in dipolar Bose-Einstein condensates. In situ measurements are used to characterize the density fluctuations near this transition. The static structure factor is extracted and used to identify the radial and angular roton excitations by their characteristic symmetries. These fluctuations peak as a function of the interaction strength indicating the crystallization transition of the system. We compare our observations to a theoretically calculated excitation spectrum allowing us to connect the crystallization mechanism with the softening of the angular roton modes.
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Affiliation(s)
- J-N Schmidt
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - J Hertkorn
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - M Guo
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - F Böttcher
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - M Schmidt
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - K S H Ng
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - S D Graham
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Langen
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - M Zwierlein
- MIT-Harvard Center for Ultracold Atoms, Research Laboratory of Electronics, and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - T Pfau
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
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21
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MacKechnie-Guire R, Fisher M, Mathie H, Kuczynska K, Fairfax V, Fisher D, Pfau T. A Systematic Approach to Comparing Thermal Activity of the Thoracic Region and Saddle Pressure Distribution beneath the Saddle in a Group of Non-Lame Sports Horses. Animals (Basel) 2021; 11:ani11041105. [PMID: 33924326 PMCID: PMC8068952 DOI: 10.3390/ani11041105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 04/05/2021] [Accepted: 04/07/2021] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Thermography is a non-invasive method for measuring surface temperatures. Due to its ease of use, it may be a convenient way of identifying hypo/hyperthermic areas under a saddle that may be related to saddle pressures. A thermal camera quantified temperatures at specific locations (left/right) of the thoracic region at three-time points; a Pliance (Novel) pressure mat determined the mean/peak saddle pressures (kPa) during a period of exercise. Differences between saddle widths in the cranial/caudal mean and peak saddle pressures were found. The maximum thermal temperatures increased post lunge and post ridden compared to the baseline. No difference between post lunge and post ridden exercise were found. The thermal activity does not appear to be representative of increased saddle pressure values. The sole use of thermal imaging for saddle fitting should be applied with caution. Abstract Thermography is a non-invasive method for measuring surface temperatures and may be a convenient way of identifying hypo/hyperthermic areas under a saddle that may be related to saddle pressures. A thermal camera quantified minimum/maximum/mean temperatures at specific locations (left/right) of the thoracic region at three-time points: (1) baseline; (2) post lunging; (3) post ridden exercise in eight non-lame sports horses ridden by the same rider. A Pliance (Novel) pressure mat determined the mean/peak saddle pressures (kPa) in the cranial and caudal regions. General linear mixed models with the horse as the random factor investigated the time point (fixed factor: baseline; lunge; ridden) and saddle fit (fixed factor: correct; wide; narrow) on thermal parameters with Bonferroni post hoc comparison. The saddle pressure data (grouped: saddle width) were assessed with an ANOVA and Tukey post hoc comparison (p ≤ 0.05). Differences between the saddle widths in the cranial/caudal mean (p = 0.05) and peak saddle pressures (p = 0.01) were found. The maximum temperatures increased post lunge (p ≤ 0.0001) and post ridden (p ≤ 0.0001) compared to the baseline. No difference between post lunge and post ridden exercise (all p ≥ 0.51) was found. The thermal activity does not appear to be representative of increased saddle pressure values. The sole use of thermal imaging for saddle fitting should be applied with caution.
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Affiliation(s)
- Russell MacKechnie-Guire
- Centaur Biomechanics, 25 Oaktree Close, Moreton Morrell, Warwickshire CV35 9BB, UK
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, Brookman’s Park, Hatfield AL9 7TA, UK;
- Correspondence:
| | - Mark Fisher
- Woolcroft Saddlery, Mays Lane, Wisbech PE13 5BU, UK; (M.F.); (D.F.)
| | - Helen Mathie
- Helen Mathie Physiotheraphy, Estate House, Matfen NE20 0RP, UK;
| | | | - Vanessa Fairfax
- Fairfax Saddles, The Saddlery, Fryers Road, Bloxwich, Walsall, West Midlands WS3 2XJ, UK;
| | - Diana Fisher
- Woolcroft Saddlery, Mays Lane, Wisbech PE13 5BU, UK; (M.F.); (D.F.)
| | - Thilo Pfau
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, Brookman’s Park, Hatfield AL9 7TA, UK;
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22
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MacKechnie-Guire R, Pfau T. Differential Rotational Movement of the Thoracolumbosacral Spine in High-Level Dressage Horses Ridden in a Straight Line, in Sitting Trot and Seated Canter Compared to In-Hand Trot. Animals (Basel) 2021; 11:ani11030888. [PMID: 33804702 PMCID: PMC8003829 DOI: 10.3390/ani11030888] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 03/09/2021] [Accepted: 03/17/2021] [Indexed: 11/16/2022] Open
Abstract
Assessing back dysfunction is a key part of the investigative process of "loss of athletic performance" in the horse and quantitative data may help veterinary decision making. Ranges of motion of differential translational and rotational movement between adjacent inertial measurement units attached to the skin over thoracic vertebrae 5, 13 and 18 (T5, T13, T18) lumbar vertebra 3 (L3) and tuber sacrale (TS) were measured in 10 dressage horses during trot in-hand and ridden in sitting trot/canter. Straight-line motion cycles were analysed using a general linear model (random factor: horse; fixed factor: exercise condition; Bonferroni post hoc correction: p < 0.05). At T5-T13 the differential heading was smaller in sitting trot (p ≤ 0.0001, 5.1° (0.2)) and canter (p ≤ 0.0001, 3.2° (0.2)) compared to trotting in-hand (7.4° (0.4)). Compared to trotting in-hand (3.4° (0.4)) at T18-L3 differential pitch was higher in sitting trot (p ≤ 0.0001, 7.5° (0.3)) and canter (p ≤ 0.0001, 6.3° (0.3)). At L3-TS, differential pitch was increased in canter (6.5° (0.5)) compared to trotting in-hand (p = 0.006, 4.9° (0.6)) and differential heading was higher in sitting trot (4° (0.2)) compared to canter (p = 0.02, 2.9° (0.3)). Compared to in-hand, reduced heading was measured in the cranial-thoracic area and increased in the caudal-thoracic and lumbar area. Pitch increased with ridden exercise from the caudal-thoracic to the sacral area.
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Affiliation(s)
- Russell MacKechnie-Guire
- Centaur Biomechanics, 25 Oaktree Close, Moreton Morrell, Warwickshire CV35 9BB, UK
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, Brookman’s Park, Hatfield AL9 7TA, UK;
- Correspondence:
| | - Thilo Pfau
- Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, Brookman’s Park, Hatfield AL9 7TA, UK;
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23
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Dieterle T, Berngruber M, Hölzl C, Löw R, Jachymski K, Pfau T, Meinert F. Transport of a Single Cold Ion Immersed in a Bose-Einstein Condensate. Phys Rev Lett 2021; 126:033401. [PMID: 33543963 DOI: 10.1103/physrevlett.126.033401] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 11/12/2020] [Indexed: 06/12/2023]
Abstract
We investigate transport dynamics of a single low-energy ionic impurity in a Bose-Einstein condensate. The impurity is implanted into the condensate starting from a single Rydberg excitation, which is ionized by a sequence of fast electric field pulses aiming to minimize the ion's initial kinetic energy. Using a small electric bias field, we study the subsequent collisional dynamics of the impurity subject to an external force. The fast ion-atom collision rate, stemming from the dense degenerate host gas and the large ion-atom scattering cross section, allow us to study a regime of frequent collisions of the impurity within only tens of microseconds. Comparison of our measurements with stochastic trajectory simulations based on sequential Langevin collisions indicate diffusive transport properties of the impurity and allows us to measure its mobility. Our results open a novel path to study dynamics of charged quantum impurities in ultracold matter.
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Affiliation(s)
- T Dieterle
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - M Berngruber
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - C Hölzl
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - R Löw
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - K Jachymski
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - T Pfau
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - F Meinert
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
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24
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Pfau T, Reilly P. How low can we go? Influence of sample rate on equine pelvic displacement calculated from inertial sensor data. Equine Vet J 2020; 53:1075-1081. [PMID: 33113248 DOI: 10.1111/evj.13371] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 09/02/2020] [Accepted: 10/22/2020] [Indexed: 11/29/2022]
Abstract
BACKGROUND Low-cost sensor devices are often limited in terms of sample rate. Based on signal periodicity, the Nyquist theorem allows determining the minimum theoretical sample rate required to adequately capture cyclical events, such as pelvic movement in trotting horses. OBJECTIVES To quantify the magnitude of errors arising with reduced sample rates when capturing biological signals using the example of pelvic time-displacement series and derived minima and maxima used to quantify movement asymmetry in lame horses. STUDY DESIGN Data comparison. METHODS Root mean square (RMS) errors between the 'reference' time-displacement series, captured with a validated inertial sensor at 100 Hz sample rate, and down-sampled time-series (8 Hz to 50 Hz) are calculated. Accuracy and precision are determined for maxima and minima derived from the time-displacement series. RESULTS Average RMS errors are <2 mm at 50 Hz sample rate, <4 mm at 40 Hz, <7 mm between 25 and 35 Hz, and increase to up to 20 mm at 20 Hz and below. Accuracy for maxima and minima is generally below 1mm. Precision is 1 mm at 50 Hz sample rate, 3 mm at 40Hz and ≥9 mm at 20 Hz and below. MAIN LIMITATIONS Only sample rate, no other sensor parameters were investigated. CONCLUSIONS Sample rate related errors for inertial sensor derived time-displacement series of pelvic movement are <2mm at 50 Hz, a rate that many low-cost loggers, smartphones or wireless sensors can sustain hence rendering these devices valid options for quantifying parameters relevant for lameness examinations in horses.
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Affiliation(s)
- Thilo Pfau
- Department of Clinical Science and Services, The Royal Veterinary College, North Mymms, Hatfield, Hertfordshire, UK
| | - Patrick Reilly
- Department of Clinical Studies New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Horan K, Kourdache K, Coburn J, Day P, Brinkley L, Carnall H, Harborne D, Hammond L, Millard S, Pfau T. Jockey Perception of Shoe and Surface Effects on Hoof-Ground Interactions and Implications for Safety in the Galloping Thoroughbred Racehorse. J Equine Vet Sci 2020; 97:103327. [PMID: 33478759 DOI: 10.1016/j.jevs.2020.103327] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 11/16/2020] [Accepted: 11/16/2020] [Indexed: 10/22/2022]
Abstract
Riding racehorses is a high-risk profession and optimizing safety alongside performance is paramount. Horseshoes play a critical role in providing traction with the ground surface and are therefore a major determinant of safety. However, the subjective perceptions of expert riders influence attitudes towards using different shoes and must be taken into consideration before any changes may be implemented. This study used a questionnaire-based method to evaluate jockey opinion of four shoeing conditions (aluminum, steel, GluShu, and barefoot) trialed at gallop over turf and artificial surfaces. Nine Lickert-style questions explored impact, cushioning, responsiveness, grip, uniformity, smoothness of ride, safety, adaptation period, and overall rating for each shoe-surface combination. A total of 94 questionnaires, based on 15 horse-rider pairs, were assessed using descriptive statistics and linear mixed models performed in SPSS (P < .05). Data indicate that shoe type significantly affected all question responses, with the exception of impact. Surface-type significantly affected perception of grip and safety. Overall, jockeys showed a preference for aluminum and steel shoes across both artificial and turf tracks. These rated "excellent" and were considered to be "very supportive" in approximately 80% of trials, with a 100% "active" response, good grip, and a quick adaptation period. In contrast, barefoot and GluShu conditions were generally considered "moderately supportive," with barefoot appearing favorable on the artificial surface. On turf, barefoot was deemed the least smooth and the only condition that jockeys sometimes marked "unsafe" (17% of responses). Future work aims to investigate the relationship between jockey opinion and hoof kinematic data.
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Affiliation(s)
- Kate Horan
- The Royal Veterinary College, Brookmans Park, Hertfordshire, UK.
| | | | | | - Peter Day
- The Royal Veterinary College, Brookmans Park, Hertfordshire, UK
| | | | | | | | | | - Sean Millard
- The Royal Veterinary College, Brookmans Park, Hertfordshire, UK
| | - Thilo Pfau
- The Royal Veterinary College, Brookmans Park, Hertfordshire, UK
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26
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MacKechnie-Guire R, Fisher M, Pfau T. Effect of a Half Pad on Pressure Distribution in Sitting Trot and Canter Beneath a Saddle Fitted to Industry Guidelines. J Equine Vet Sci 2020; 96:103307. [PMID: 33349411 DOI: 10.1016/j.jevs.2020.103307] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 10/13/2020] [Accepted: 10/13/2020] [Indexed: 11/17/2022]
Abstract
Using a half pad beneath a saddle can be beneficial for improving saddle fit. However, there is a paucity of evidence on half pad use when used beneath a correctly fitted saddle. The aim was to quantify the effect that three different half pads have on pressure distribution beneath a saddle fitted following industry guidelines. Twelve nonlame horses were ridden by experienced riders in sitting trot and canter on each rein (three repeats). Saddle fit, with a high-withered cotton saddle cloth (control) compared with three half pads (viscoelastic gel, wool, and medical-grade, closed-cell foam), was evaluated by five qualified saddle fitters. A Pliance (Novel) pressure mat determined saddle pressures. Mean and peak pressures (kPa) beneath the saddle were compared using a general linear mixed model with horse as a random factor and half pad type and rein as fixed factors with a Bonferroni post hoc correction (P ≤ .05). In sitting trot, in the cranial region, peak (P = .008) and mean pressures (P = .03) were highest when using the gel half pad compared with the control. In the caudal region in sitting trot, mean pressures were lowest when using the wool half pad (P = .0002). In canter, increased peak (P = .04) and mean (P = .02) pressures were found in the cranial region of the saddle with the gel half pad. In canter, with the foam half pad, reduced mean pressure (P = .002) in the caudal region was found. It is essential that the use and type of a half pad, to be used beneath a well-fitted saddle, is discussed with a qualified saddle fitter.
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Affiliation(s)
- Russell MacKechnie-Guire
- Centaur Biomechanics, Moreton Morrell, Warwickshire, UK; Royal Veterinary College, Structure and Motion Laboratory, The Royal Veterinary College, Hatfield, UK.
| | | | - Thilo Pfau
- Royal Veterinary College, Structure and Motion Laboratory, The Royal Veterinary College, Hatfield, UK
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Lynch NP, Jones SA, Bazley-White LG, Wilson ZF, Raffetto J, Pfau T, Cheetham J, Perkins JD. Ex vivo modeling of the airflow dynamics and two-and three-dimensional biomechanical effects of suture placements for prosthetic laryngoplasty in horses. Am J Vet Res 2020; 81:665-672. [PMID: 32700998 DOI: 10.2460/ajvr.81.8.665] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To identify the degree of left arytenoid cartilage (LAC) abduction that allows laryngeal airflow similar to that in galloping horses, assess 2-D and 3-D biomechanical effects of prosthetic laryngoplasty on LAC movement and airflow, and determine the influence of suture position through the muscular process of the arytenoid cartilage (MPA) on these variables. SAMPLE 7 equine cadaver larynges. PROCEDURES With the right arytenoid cartilage maximally abducted and inspiratory airflow simulated by vacuum, laryngeal airflow and translaryngeal pressure and impedance were measured at 12 incremental LAC abduction forces (0% to 100% [maximum abduction]) applied through laryngoplasty sutures passed caudocranially or mediolaterally through the left MPA. Cross-sectional area of the rima glottis and left-to-right angle quotient were determined from photographs at each abduction force; CT images were obtained at alternate forces. Arytenoid and cricoid cartilage markers allowed calculation of LAC roll, pitch, and yaw through use of Euler angles on 3-D reconstructed CT images. RESULTS Translaryngeal pressure and impedance decreased, and airflow increased rapidly at low abduction forces, then slowed until a plateau was reached at approximately 50% of maximum abduction force. The greatest LAC motion was rocking (pitch). Suture position through the left MPA did not significantly affect airflow data. Approximately 50% of maximum abduction force, corresponding to a left arytenoid angle of approximately 30° and left-to-right angle quotient of 0.79 to 0.84, allowed airflow of approximately 61 ± 6.5 L/s. CONCLUSIONS AND CLINICAL RELEVANCE Ex vivo modeling results suggested little benefit to LAC abduction forces > 50%, which allowed airflow similar to that reported elsewhere for galloping horses.
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Day P, Collins L, Horan K, Weller R, Pfau T. The Effect of Tungsten Road Nails on Upper Body Movement Asymmetry in Horses Trotting on Tarmac. J Equine Vet Sci 2020; 90:103000. [PMID: 32534777 DOI: 10.1016/j.jevs.2020.103000] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 03/18/2020] [Accepted: 03/20/2020] [Indexed: 11/28/2022]
Abstract
Tungsten road nails are commonly used by farriers to increase grip between the hoof and the ground surface. There is limited evidence relating the use of road nails to the fundamental mechanics of movement. Grip is important for efficient deceleration on landing and subsequent propulsion, but this must be balanced against an amount of slip to divide the landing force into horizontal as well as vertical subcomponents. Here, we conducted an intervention study to quantify the effect of lateral heel road nail placement on weight bearing and propulsion in 10 horses trotting on tarmac. Wireless inertial measurement units measured vertical movement asymmetry. Differences in head and pelvic movement asymmetry before/after subsequent application of laterally placed road nails to forelimb and hindlimb hooves in a randomized order were compared to zero value (no change) with a one-sample t-test, P < .05. Left-to-right tuber coxae movement amplitude difference was significantly more negative (-3.25 mm, P = .03), suggesting more right than left tuber coxae movement amplitude, after application of a road nail to the left hindlimb. No movement asymmetries at the poll, withers, or sacrum were detected after nail placement (all P > .055). Pelvic movement indicates a very small increase in weight bearing and propulsion provided by the hindlimb with a laterally placed road nail compared to the contralateral hindlimb. Further work is needed to investigate slip- and grip-related parameters at the level of the hoof and to investigate the long-term consequences of very small changes in movement asymmetry.
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Affiliation(s)
- Peter Day
- Department of Clinical Science and Services, The Royal Veterinary College, University of London, Hatfield, UK.
| | - Lee Collins
- Department of Clinical Science and Services, The Royal Veterinary College, University of London, Hatfield, UK
| | - Kate Horan
- Department of Clinical Science and Services, The Royal Veterinary College, University of London, Hatfield, UK
| | - Renate Weller
- Department of Clinical Science and Services, The Royal Veterinary College, University of London, Hatfield, UK
| | - Thilo Pfau
- Department of Clinical Science and Services, The Royal Veterinary College, University of London, Hatfield, UK
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MacKechnie-Guire R, MacKechnie-Guire E, Fairfax V, Fisher M, Hargreaves S, Pfau T. The Effect That Induced Rider Asymmetry Has on Equine Locomotion and the Range of Motion of the Thoracolumbar Spine When Ridden in Rising Trot. J Equine Vet Sci 2020; 88:102946. [PMID: 32303298 DOI: 10.1016/j.jevs.2020.102946] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 01/23/2020] [Accepted: 01/27/2020] [Indexed: 11/16/2022]
Abstract
There is a paucity of evidence on the effect that rider asymmetry has on equine locomotion. The aim of this study was to evaluate the effect of rider asymmetry on equine locomotion by using a novel approach to induce rider asymmetry. Ten nonlame horses were recruited for this study. Joint center markers were used to capture 2D kinematics (Quintic Biomechanics) of the horse and rider and horses were equipped with seven inertial sensors positioned at the fifth (T5) and eighteenth (T18) thoracic vertebrae, third lumbar (L3) vertebra, tubera sacrale (TS), and left and right tubera coxae. Rider asymmetry was induced by shortening the ventral aspect of one stirrup by 5 cm. Kinematic data were compared between conditions using a mixed model with the horse defined as a random factor and stirrup condition (symmetrical stirrups and asymmetrical stirrups) and direction (inside and outside) defined as fixed factors. Data from riders where the right stirrup was shortened were mirrored to reflect a left stirrup being shortened. To determine differences between conditions, a significance of P ≤ .05 was set. On the rein with the shortened stirrup on the outside: an increase in lateral bending range of motion (ROM) at T5 (P = .003), L3 (P = .04), and TS (P = .02), an increase in mediolateral displacement at T5 (P = .04), T18 (P = .04), and L3 (0.03) were found. An increase in maximum fetlock extension was apparent for both the front (P = .01) and hind limb (P = .04) on the contralateral side to the shortened stirrup; for the asymmetrical stirrup condition on the rein with the shortened stirrup on the inside: an increase in flexion-extension ROM at T5 (P = .03) and L3 (P = .04), axial rotation at T5 (P = .05), and lateral bending of T5 (P = .03), L3 (P = .04), and TS (P = .02). Asymmetric rider position appears to have an effect on the kinematics of the thoracolumbar spine. These findings warrant further investigation to understand the long-term impact this may have on equine locomotor health.
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Affiliation(s)
- Russell MacKechnie-Guire
- Centaur Biomechanics, Moreton Morrell, Warwickshire, UK; Department of Clinical Science and Services, Royal Veterinary College, The Royal Veterinary College, Hatfield, UK.
| | | | - Vanessa Fairfax
- FairfaxSaddles, The Saddlery, Bloxwich, Walsall, West Midlands, UK
| | | | | | - Thilo Pfau
- Department of Clinical Science and Services, Royal Veterinary College, The Royal Veterinary College, Hatfield, UK
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Hertkorn J, Böttcher F, Guo M, Schmidt JN, Langen T, Büchler HP, Pfau T. Fate of the Amplitude Mode in a Trapped Dipolar Supersolid. Phys Rev Lett 2019; 123:193002. [PMID: 31765213 DOI: 10.1103/physrevlett.123.193002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 09/13/2019] [Indexed: 06/10/2023]
Abstract
We theoretically investigate the spectrum of elementary excitations of a trapped dipolar quantum gas across the BEC-supersolid phase transition. Our calculations reveal the existence of distinct Higgs amplitude and Nambu-Goldstone modes that emerge from the softening roton modes of the dipolar BEC at the phase transition point. On the supersolid side of the transition, the energy of the Higgs amplitude mode increases rapidly, leading to a strong coupling to higher-lying modes. Our Letter highlights how the symmetry-breaking nature of the supersolid state translates to finite-size systems.
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Affiliation(s)
- J Hertkorn
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universitt Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - F Böttcher
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universitt Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - M Guo
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universitt Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - J N Schmidt
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universitt Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Langen
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universitt Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - H P Büchler
- Institute for Theoretical Physics III and Center for Integrated Quantum Science and Technology, Universitt Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Pfau
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universitt Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
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Engel F, Dieterle T, Hummel F, Fey C, Schmelcher P, Löw R, Pfau T, Meinert F. Precision Spectroscopy of Negative-Ion Resonances in Ultralong-Range Rydberg Molecules. Phys Rev Lett 2019; 123:073003. [PMID: 31491092 DOI: 10.1103/physrevlett.123.073003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Indexed: 06/10/2023]
Abstract
The level structure of negative ions near the electron detachment limit dictates the low-energy scattering of an electron with the parent neutral atom. We demonstrate that a single ultracold atom bound inside a Rydberg orbit forming an ultralong-range Rydberg molecule provides an atomic-scale system that is highly sensitive to electron-neutral scattering and thus allows for detailed insights into the underlying near-threshold anion states. Our measurements reveal the so-far unobserved fine structure of the ^{3}P_{J} triplet of Rb^{-} and allows us to extract parameters of the associated p-wave scattering resonances that deviate from previous theoretical estimates. Moreover, we observe a novel alignment mechanism for Rydberg molecules mediated by spin-orbit coupling in the negative ion.
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Affiliation(s)
- F Engel
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Dieterle
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - F Hummel
- Zentrum für optische Quantentechnologien, Fachbereich Physik, Universität Hamburg, 22761 Hamburg, Germany
| | - C Fey
- Zentrum für optische Quantentechnologien, Fachbereich Physik, Universität Hamburg, 22761 Hamburg, Germany
| | - P Schmelcher
- Zentrum für optische Quantentechnologien, Fachbereich Physik, Universität Hamburg, 22761 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, 22761 Hamburg, Germany
| | - R Löw
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Pfau
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - F Meinert
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
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Parkes RSV, Weller R, Pfau T, Witte TH. The Effect of Training on Stride Duration in a Cohort of Two-Year-Old and Three-Year-Old Thoroughbred Racehorses. Animals (Basel) 2019; 9:ani9070466. [PMID: 31336595 PMCID: PMC6680649 DOI: 10.3390/ani9070466] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 07/15/2019] [Accepted: 07/17/2019] [Indexed: 11/26/2022] Open
Abstract
Simple Summary Objective gait monitoring via GPS and motion sensors is becoming increasingly popular with racehorse trainers. This has the potential to assist in early detection of lameness and performance issues. This study sought to identify normal changes in gait in a population of two and three-year-old racehorses in order to inform future studies. We found that horses decrease their stride duration at a given speed over time with training. Stride duration appears to increase with increased distance galloped, but this effect is reduced over a training season and presumably increased fitness, so this may serve as a useful indicator for fatigue. Abstract Objective gait monitoring is increasingly accessible to trainers. A more comprehensive understanding of ‘normal’ gait adaptations is required. Forty two-year-old thoroughbred racehorses were recruited when entering training and followed for 22 months. Gait analysis was performed by equipping each horse with an inertial measurement unit with inbuilt GPS (GPS-IMU) mounted on the dorsum. Horses were exercised as per their regular training regimen. Data were analysed using a linear mixed model. For two-year-old horses, there was a non-linear pattern of stride duration (SD) over time (p < 0.001) with SD decreasing initially and then ‘flattening off’ over time (linear and quadratic coefficients −0.29 ms/week and 0.006 ms/week2). Horses showed an increase in SD of 2.21 ms (p < 0.001) per 100 m galloped, and over time, SD decreased by 0.04 ms (p < 0.001) with each 100 m galloped per week. Three-year-old horses overall showed no change in SD over time (p = 0.52), but those that had a period of time off showed a decrease in SD of −0.59 ms per week (p = 0.02). They showed an increase in SD of 1.99 ms (p < 0.001) per 100 m galloped, and horses that had a period of time off showed an increase in stride duration of 1.05 ms per 100 m galloped (p = 0.01) compared to horses which did not have time off. Horses demonstrate an adaptation to high-speed exercise over time. SD decreases with training when other factors are controlled for in naïve horses.
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Affiliation(s)
- Rebecca S V Parkes
- Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong.
- Royal Veterinary College, Hatfield, Herts AL9 7TA, UK.
| | - Renate Weller
- Royal Veterinary College, Hatfield, Herts AL9 7TA, UK
| | - Thilo Pfau
- Royal Veterinary College, Hatfield, Herts AL9 7TA, UK
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Maisonpierre IN, Sutton MA, Harris P, Menzies-Gow N, Weller R, Pfau T. Accelerometer activity tracking in horses and the effect of pasture management on time budget. Equine Vet J 2019; 51:840-845. [PMID: 31009100 DOI: 10.1111/evj.13130] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 04/11/2019] [Indexed: 11/27/2022]
Abstract
BACKGROUND Accelerometry is an accepted means of quantifying human physical activity. Quantitative physical activity tracking could be beneficial for studies into equine health and disease prevention, for example in relation to obesity management. OBJECTIVES Validate accelerometer use in grazing horses, determine between-day repeatability, and assess the effects of pasture size on time budget (i.e. duration in each activity category). STUDY DESIGN Proof of concept. METHODS Accelerometers (ActiGraph) were positioned at the poll. Horses underwent 5 min of observed activity in three categories: standing, grazing and ambulating. Receiver-operating characteristic curve analysis, used on ten second data epochs, calculated cut points between the activities. A 20-day study was then undertaken on 6 horses at pasture. Time in each category (per day) was deduced; a Mann Whitney U test was performed to compare standard vs. small paddock and day vs. night turn out. RESULTS Cut-off values with the optimum sensitivity (94.7-97.7%) and specificity (94.7-96.8%) were found to be <127.6 counts for standing, 127.6-702.7 counts for grazing and >702.7 counts for ambulating. Repeatability was analysed descriptively: Median (IQR) of the between-day difference in minutes standing, grazing and ambulating were 46.9 (21.3-87.9), 77.3 (40.2-124.5) and 15.6 (6.8-40.2) respectively. Median times standing and ambulating were significantly different between standard and small paddocks: standing: 8.7 vs. 10.3 h (P<0.001); ambulating: 55.7 vs. 39.6 min (P = 0.002). There was no significant difference in the median time spent grazing. There were significant differences between day and night: standing: 32.95% vs. 50.97% (P = 0.001), grazing: 60.81% vs. 46.77% (P<0.001) and ambulating: 4.57% vs. 2.40% (P<0.001). MAIN LIMITATIONS Small sample size and lack of cross-validation of cut-off points on independent, 'unseen' data. CONCLUSIONS Accelerometry can differentiate standing, grazing and ambulating in horses. Our proof-of-concept study demonstrates modifying pasture size influences activity budgets; opening avenues into studying obesity management.
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Affiliation(s)
- I N Maisonpierre
- Department of Clinical Science and Services, The Royal Veterinary College, Hatfield, UK
| | - M A Sutton
- Department of Clinical Science and Services, The Royal Veterinary College, Hatfield, UK
| | - P Harris
- Mars Horsecare UK Ltd, Equine Studies Group, Waltham Centre for Pet Nutrition, Bury St Edmunds, UK
| | - N Menzies-Gow
- Department of Clinical Science and Services, The Royal Veterinary College, Hatfield, UK
| | - R Weller
- Department of Clinical Science and Services, The Royal Veterinary College, Hatfield, UK
| | - T Pfau
- Department of Clinical Science and Services, The Royal Veterinary College, Hatfield, UK
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Abstract
Quantitative gait analysis in the lame horse has gained in popularity, likely related to the potential to remove bias from the clinical decision-making process. Its implementation into clinical practice is, however, not without challenges. This review visits some of the challenges related to the use of thresholds and guideline values in the context of clinical decision making, as well as when applied to scientific studies based on relevant published studies: issues such as ‘normal day-to-day variation’, conformational asymmetry and the often limited number of parameters that are being quantified. Emphasis is put on outlining the basic underlying principles relating to head nod and hip hike, which are explained in the context of Newtonian mechanics associating reduced vertical acceleration of the upper body to reduced force production with the limb that is in contact with the ground during that time period. Further to quantifying what can be seen ‘by eye’, the review also visits phenomena such as asymmetries in weight bearing or pushoff and compensatory mechanisms, with emphasis on measurement of withers movement and thoughts about multilimb lameness. The review concludes with thoughts about additional parameters such as limb movement and movement of the thoraco-lumbo-sacral area, which may provide additional insights into lameness and poor performance but are at current less frequently included into clinical gait analysis in the horse.
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Affiliation(s)
- Thilo Pfau
- Department of Clinical Science and Services, The Royal Veterinary College, London
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Engel F, Dieterle T, Schmid T, Tomschitz C, Veit C, Zuber N, Löw R, Pfau T, Meinert F. Observation of Rydberg Blockade Induced by a Single Ion. Phys Rev Lett 2018; 121:193401. [PMID: 30468597 DOI: 10.1103/physrevlett.121.193401] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Indexed: 06/09/2023]
Abstract
We study the long-range interaction of a single ion with a highly excited ultracold Rydberg atom and report on the direct observation of an ion-induced Rydberg excitation blockade mediated over tens of micrometer distances. Our hybrid ion-atom system is directly produced from an ultracold atomic ensemble via near-threshold photoionization of a single Rydberg excitation, employing a two-photon scheme that is specifically suited for generating a very low-energy ion. The ion's motion is precisely controlled by small electric fields, which allows us to analyze the blockade mechanism for a range of principal quantum numbers. Finally, we explore the capability of the ion as a high-sensitivity, single-atom-based electric field sensor. The observed ion-Rydberg-atom interaction is of current interest for entanglement generation or studies of ultracold chemistry in hybrid ion-atom systems.
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Affiliation(s)
- F Engel
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Dieterle
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Schmid
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - C Tomschitz
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - C Veit
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - N Zuber
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - R Löw
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Pfau
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - F Meinert
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
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Mackechnie-Guire R, Mackechnie-Guire E, Fisher M, Mathie H, Bush R, Pfau T, Weller R. Relationship Between Saddle and Rider Kinematics, Horse Locomotion, and Thoracolumbar Pressures in Sound Horses. J Equine Vet Sci 2018. [DOI: 10.1016/j.jevs.2018.06.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Greve L, Pfau T, Dyson S. Alterations in body lean angle in lame horses before and after diagnostic analgesia in straight lines in hand and on the lunge. Vet J 2018; 239:1-6. [PMID: 30197103 DOI: 10.1016/j.tvjl.2018.07.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 05/27/2018] [Accepted: 07/15/2018] [Indexed: 12/18/2022]
Abstract
Altered body lean has been subjectively observed during lungeing in lame horses. The objectives were to quantify the influence of lameness on body lean in trot on the lunge and to investigate the influence of improvement in lameness on the differences in body lean between reins. Thirteen lame horses were trotted in straight lines and lunged on a 10m-diameter circle on both reins before and after lameness was subjectively substantially improved by diagnostic analgesia. A global position system-aided inertial measurement unit attached to the tubera sacrale quantified body lean. Differences between reins in body lean before and after diagnostic analgesia were calculated and means were determined. Five and eight horses had unilateral and bilateral hindlimb lameness, respectively. Two of five horses with unilateral and three of eight horses with bilateral lameness leaned more on the rein with the lame or lamer hindlimb on the inside of the circle (difference between reins 5-8°). Two of five horses with unilateral and two of eight horses with bilateral lameness leaned more on the rein with the lame or lamer hindlimb on the outside of the circle (4-10°). Four horses, one with unilateral and three with bilateral lameness, had only 1° difference in body lean angle between left and right reins. When lameness was improved by diagnostic analgesia, the body lean changed significantly towards similar leaning on left and right reins (mean angle changed from 8.8° to 10.0° (P=0.03) on one rein and 13.4° to 10.8° (P=0.002) on the other rein). It was concluded that body lean becomes more symmetrical between reins after improvement in lameness using diagnostic analgesia.
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Affiliation(s)
- L Greve
- Centre for Equine Studies, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK; Department of Clinical Science and Services, The Royal Veterinary College, University of London, Hawkshead Lane, North Mymms, Hatfield AL9 7TA, UK.
| | - T Pfau
- Department of Clinical Science and Services, The Royal Veterinary College, University of London, Hawkshead Lane, North Mymms, Hatfield AL9 7TA, UK
| | - S Dyson
- Centre for Equine Studies, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK
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Affiliation(s)
- R Weller
- Department of Veterinary Clinical Sciences, Royal Veterinary College, Hatfield, Hertfordshire, UK
| | - A Barstow
- Department of Veterinary Clinical Sciences, Royal Veterinary College, Hatfield, Hertfordshire, UK
| | - H Price
- Department of Veterinary Clinical Sciences, Royal Veterinary College, Hatfield, Hertfordshire, UK
| | - T Pfau
- Department of Veterinary Clinical Sciences, Royal Veterinary College, Hatfield, Hertfordshire, UK
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van Weeren PR, Pfau T, Rhodin M, Roepstorff L, Serra Bragança F, Weishaupt MA. What is lameness and what (or who) is the gold standard to detect it? Equine Vet J 2018; 50:549-551. [PMID: 29953639 DOI: 10.1111/evj.12970] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- P R van Weeren
- Department of Equine Sciences, Utrecht University, Utrecht, the Netherlands
| | - T Pfau
- Department of Clinical Science and Services, The Royal Veterinary College, University of London, Hatfield, UK
| | - M Rhodin
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - L Roepstorff
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - F Serra Bragança
- Department of Clinical Science and Services, The Royal Veterinary College, University of London, Hatfield, UK
| | - M A Weishaupt
- Equine Department, University of Zurich, Zurich, Switzerland
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Rhodin M, Persson-Sjodin E, Egenvall A, Serra Bragança FM, Pfau T, Roepstorff L, Weishaupt MA, Thomsen MH, van Weeren PR, Hernlund E. Vertical movement symmetry of the withers in horses with induced forelimb and hindlimb lameness at trot. Equine Vet J 2018; 50:818-824. [PMID: 29658147 PMCID: PMC6175082 DOI: 10.1111/evj.12844] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2017] [Accepted: 03/30/2018] [Indexed: 12/01/2022]
Abstract
Background The main criteria for lameness assessment in horses are head movement for forelimb lameness and pelvic movement for hindlimb lameness. However, compensatory head nod in horses with primary hindlimb lameness is a well‐known phenomenon. This compensatory head nod movement can be easily misinterpreted as a sign of primary ipsilateral forelimb lameness. Therefore, discriminating compensatory asymmetries from primary directly pain‐related movement asymmetries is a prerequisite for successful lameness assessment. Objectives To investigate the association between head, withers and pelvis movement asymmetry in horses with induced forelimb and hindlimb lameness. Study design Experimental study. Methods In 10 clinically sound Warmblood riding horses, forelimb and hindlimb lameness were induced using a sole pressure model. The horses were then trotted on a treadmill. Three‐dimensional optical motion capture was used to collect kinematic data from reflective markers attached to the poll, withers and tubera sacrale. The magnitude and side (left or right) of the following symmetry parameters, vertical difference in minimum position, maximum position and range‐up were calculated for head, withers, and pelvis. Mixed models were used to analyse data from induced forelimb and hindlimb lameness. Results For each mm increase in pelvic asymmetry in response to hindlimb lameness induction, withers movement asymmetry increased by 0.35–0.55 mm, but towards the contralateral side. In induced forelimb lameness, for each mm increase in head movement asymmetry, withers movement asymmetry increased by 0.05–0.10 mm, in agreement with the head movement asymmetry direction, both indicating lameness in the induced forelimb. Main limitations Results must be confirmed in clinically lame horses trotting overground. Conclusions The vertical asymmetry pattern of the withers discriminated a head nod associated with true forelimb lameness from the compensatory head movement asymmetry caused by primary hindlimb lameness. Measuring movement symmetry of the withers may, thus, aid in determining primary lameness location.
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Affiliation(s)
- M Rhodin
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - E Persson-Sjodin
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - A Egenvall
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - F M Serra Bragança
- Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - T Pfau
- Department of Clinical Science and Services, The Royal Veterinary College, University of London, North Mymms, Hatfield, Hertfordshire, UK
| | - L Roepstorff
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - M A Weishaupt
- Department, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - M H Thomsen
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Taastrup, Denmark
| | - P R van Weeren
- Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - E Hernlund
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
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Barstow A, Bailey J, Campbell J, Harris C, Weller R, Pfau T. Does 'hacking' surface type affect equine forelimb foot placement, movement symmetry or hoof impact deceleration during ridden walk and trot exercise? Equine Vet J 2018; 51:108-114. [PMID: 29665054 DOI: 10.1111/evj.12952] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 03/31/2018] [Indexed: 11/30/2022]
Abstract
BACKGROUND Both pleasure and competition horses regularly exercise on surfaces such as tarmac, gravel and turf during 'hacking'. Despite this, there is limited evidence relating to the effect of these surfaces upon foot-surface interaction. OBJECTIVES To investigate forelimb foot placement, hoof vibration and movement symmetry in pleasure horses on three commonly encountered hacking surfaces. STUDY DESIGN Quantitative gait study in a convenience sample. METHODS Six horses regularly partaking in hacking exercise were ridden in walk and trot on all surfaces. Horses were equipped with one hoof-mounted, accelerometer and four body-mounted inertial measurement units (IMUs) to measure foot impact and movement symmetry. High-speed (400 FPS) video footage of foot-placement was acquired (dorsal, palmar, lateral views). Foot-impact and movement symmetry were analysed with a mixed effects model and Bowker symmetry tests for foot-placement analysis. RESULTS Vibration power and frequency parameters increase as perceived surface firmness increases from grass, to gravel, to tarmac (P≤0.001). Vibration power parameters were consistently greater at trot compared with walk (P≤0.001), but the same was not true for vibration frequency (P≥0.2). Greatest movement asymmetry was recorded during grass surface trotting. No significant difference in foot-placement was detected between the three surfaces. MAIN LIMITATIONS This was a field study using three commonly encountered hacking surfaces. Surface properties change easily with water content and temperature fluctuations so care must be taken when considering other similar surfaces, especially at different times of the year. Six leisure horses were used so the results may not be representative of horses of all types. CONCLUSIONS Vibration parameters generally increase as perceived surface firmness increases. Increasing speed alters vibration power but not frequency. Further investigations are required to determine the role that this may play in the development of musculoskeletal disease in horses.
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Affiliation(s)
- A Barstow
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, Hertfordshire, UK.,Structure and Motion Laboratory, Royal Veterinary College, Hatfield, Hertfordshire, UK
| | - J Bailey
- Structure and Motion Laboratory, Royal Veterinary College, Hatfield, Hertfordshire, UK
| | - J Campbell
- Structure and Motion Laboratory, Royal Veterinary College, Hatfield, Hertfordshire, UK
| | - C Harris
- Structure and Motion Laboratory, Royal Veterinary College, Hatfield, Hertfordshire, UK
| | - R Weller
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, Hertfordshire, UK.,Structure and Motion Laboratory, Royal Veterinary College, Hatfield, Hertfordshire, UK
| | - T Pfau
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, Hertfordshire, UK.,Structure and Motion Laboratory, Royal Veterinary College, Hatfield, Hertfordshire, UK
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Kleinbach KS, Engel F, Dieterle T, Löw R, Pfau T, Meinert F. Ionic Impurity in a Bose-Einstein Condensate at Submicrokelvin Temperatures. Phys Rev Lett 2018; 120:193401. [PMID: 29799221 DOI: 10.1103/physrevlett.120.193401] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Indexed: 06/08/2023]
Abstract
Rydberg atoms immersed in a Bose-Einstein condensate interact with the quantum gas via electron-atom and ion-atom interaction. To suppress the typically dominant electron-neutral interaction, Rydberg states with a principal quantum number up to n=190 are excited from a dense and tightly trapped micron-sized condensate. This allows us to explore a regime where the Rydberg orbit exceeds the size of the atomic sample by far. In this case, a detailed line shape analysis of the Rydberg excitation spectrum provides clear evidence for ion-atom interaction at temperatures well below a microkelvin. Our results may open up ways to enter the quantum regime of ion-atom scattering for the exploration of charged quantum impurities and associated polaron physics.
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Affiliation(s)
- K S Kleinbach
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - F Engel
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Dieterle
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - R Löw
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Pfau
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - F Meinert
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
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Serra Bragança FM, Rhodin M, Wiestner T, Hernlund E, Pfau T, van Weeren P, Weishaupt MA. Quantification of the effect of instrumentation error in objective gait assessment in the horse on hindlimb symmetry parameters. Equine Vet J 2018; 50:370-376. [PMID: 29032614 PMCID: PMC5900976 DOI: 10.1111/evj.12766] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 10/10/2017] [Indexed: 11/27/2022]
Abstract
BACKGROUND Objective gait analysis is becoming more popular as a tool assisting veterinarians during the clinical lameness exam. At present, there is only limited information on the effect of misplacement of markers/motion-sensors. OBJECTIVES To investigate and describe the effect of marker misplacement on commonly calculated pelvic symmetry parameters. STUDY DESIGN Experimental study. METHODS Each horse was equipped with custom-made devices consisting of several reflective markers arranged in a predefined manner with a reference marker correctly positioned regarding the anatomical landmark and several misplaced markers along the sagittal and transverse planes. Linear regression analysis was used to estimate the effect of marker misplacement. RESULTS For the tubera sacrale, each cm of left/right misplacement led to a difference in minimum position of the pelvis (PDmin) of ±1.67 mm (95% CI 1.54-1.8 mm) (P<0.001); maximum position of the pelvis (PDmax) was affected by ±0.2 mm (95% CI 0.071-0.33 mm) (P = 0.003). With respect to cranial/caudal misplacement, each cm of misplacement resulted in a PDmin difference of ±0.04 mm (95% CI -0.09 to 0.16 mm) (P = 0.56) and a PDmax difference of ±0.008 mm (95% CI -0.13 to 0.12 mm) (P = 0.9). For the tubera coxae, each cm of vertical misplacement led to a difference in the displacement amplitude between left and right tubera coxae (Hip-Hike_Diff) of ±1.56 mm (95% CI 1.35-1.77 mm) (P<0.001); for the cranial/caudal misplacement, this was ±0.82 mm (95% CI 0.66-0.97 mm) (P<0.001). MAIN LIMITATIONS Only three horses were used in this experiment and the study design did not permit to determine the influence of marker misplacement on the evaluation of different degrees of lameness. CONCLUSIONS Marker misplacement significantly affects calculated symmetry parameters of the pelvis. The observed errors are overall small but significant. In cases of mildly asymmetrical horses, this error might influence the decision-making process whereas in more severe asymmetries, the influence of the error effect may become less significant.
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Affiliation(s)
- F. M. Serra Bragança
- Department of Equine SciencesFaculty of Veterinary MedicineUtrecht UniversityUtrechtThe Netherlands
| | - M. Rhodin
- Department of Clinical SciencesSwedish University of Agricultural SciencesUppsalaSweden
| | - T. Wiestner
- Equine DepartmentVetsuisse Faculty University of ZurichZurichSwitzerland
| | - E. Hernlund
- Department of Clinical SciencesSwedish University of Agricultural SciencesUppsalaSweden
| | - T. Pfau
- Department of Clinical Science and ServicesThe Royal Veterinary CollegeHatfieldHertfordshireUK
| | - P.R. van Weeren
- Department of Equine SciencesFaculty of Veterinary MedicineUtrecht UniversityUtrechtThe Netherlands
| | - M. A. Weishaupt
- Equine DepartmentVetsuisse Faculty University of ZurichZurichSwitzerland
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Schmid T, Veit C, Zuber N, Löw R, Pfau T, Tarana M, Tomza M. Rydberg Molecules for Ion-Atom Scattering in the Ultracold Regime. Phys Rev Lett 2018; 120:153401. [PMID: 29756888 DOI: 10.1103/physrevlett.120.153401] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Indexed: 06/08/2023]
Abstract
We propose a novel experimental method to extend the investigation of ion-atom collisions from the so far studied cold, essentially classical regime to the ultracold, quantum regime. The key aspect of this method is the use of Rydberg molecules to initialize the ultracold ion-atom scattering event. We exemplify the proposed method with the lithium ion-atom system, for which we present simulations of how the initial Rydberg molecule wave function, freed by photoionization, evolves in the presence of the ion-atom scattering potential. We predict bounds for the ion-atom scattering length from ab initio calculations of the interaction potential. We demonstrate that, in the predicted bounds, the scattering length can be experimentally determined from the velocity of the scattered wave packet in the case of ^{6}Li^{+}-^{6}Li and from the molecular ion fraction in the case of ^{7}Li^{+}-^{7}Li. The proposed method to utilize Rydberg molecules for ultracold ion-atom scattering, here particularized for the lithium ion-atom system, is readily applicable to other ion-atom systems as well.
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Affiliation(s)
- T Schmid
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - C Veit
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - N Zuber
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - R Löw
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Pfau
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - M Tarana
- J. Heyrovský Institute of Physical Chemistry of the ASCR, v.v.i., Dolejškova 2155/3, 182 23 Prague 8, Czech Republic
| | - M Tomza
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
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Pfau T, Sepulveda Caviedes MF, McCarthy R, Cheetham L, Forbes B, Rhodin M. Comparison of visual lameness scores to gait asymmetry in racing Thoroughbreds during trot in‐hand. EQUINE VET EDUC 2018. [DOI: 10.1111/eve.12914] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- T. Pfau
- Department of Clinical Science and Services The Royal Veterinary CollegeHatfield Hertfordshire UK
- Structure and Motion Lab The Royal Veterinary College Hatfield Hertfordshire UK
| | - M. F. Sepulveda Caviedes
- Department of Clinical Science and Services The Royal Veterinary CollegeHatfield Hertfordshire UK
- Structure and Motion Lab The Royal Veterinary College Hatfield Hertfordshire UK
| | - R. McCarthy
- Department of Clinical Science and Services The Royal Veterinary CollegeHatfield Hertfordshire UK
| | - L. Cheetham
- Department of Clinical Science and Services The Royal Veterinary CollegeHatfield Hertfordshire UK
| | - B. Forbes
- Singapore Turf Club SingaporeSingapore
| | - M. Rhodin
- Department of Anatomy, Physiology and Biochemistry Swedish University of Agricultural Sciences Uppsala Sweden
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Zhang H, Zhu B, Park S, Doerr C, Aydinlik M, Geyer J, Pfau T, Pendock G, Aroca R, Liu F, Rasmussen C, Mikkelsen B, Borel PI, Geisler T, Jensen R, Peckham DW, Lingle R, Vaidya D, Yan MF, Wisk PW, DiGiovanni DJ. Real-time transmission of 16 Tb/s over 1020km using 200Gb/s CFP2-DCO. Opt Express 2018; 26:6943-6948. [PMID: 29609380 DOI: 10.1364/oe.26.006943] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 03/01/2018] [Indexed: 06/08/2023]
Abstract
We demonstrate real-time transmission of 16 Tb/s (80x200Gb/s) over 1020km TeraWave ULL fiber with 170km span length using the world's first 200Gb/s CFP2-DCO module with a record low power consumption less than 0.1W/Gbps.
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Sepulveda Caviedes MF, Forbes BS, Pfau T. Repeatability of gait analysis measurements in Thoroughbreds in training. Equine Vet J 2018; 50:513-518. [PMID: 29284186 DOI: 10.1111/evj.12802] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 12/19/2017] [Indexed: 11/29/2022]
Abstract
BACKGROUND With the view of implementing gait symmetry measurements in Thoroughbreds in training for early detection of injuries, repeatability of inertial measurement unit (IMU) gait parameters needs to be established. OBJECTIVES To assess the variation of head and pelvis movement symmetry in Thoroughbreds in training. STUDY DESIGN Repeated observations in horses in race training. METHODS Daily and weekly repeat gait assessments were conducted in 14 Thoroughbreds equipped with IMUs on poll, sacrum and right (RTC) and left (LTC) tuber coxae. Gait was assessed in trot, in-hand, on a level concrete surface. Difference between vertical displacement minima and maxima and range of motion (ROM) were obtained. Ranges containing 50% (median), 75, 90 and 95% of absolute daily and weekly differences were calculated and intraclass correlation coefficients (ICC) calculated for daily and weekly repeats. RESULTS Median absolute daily differences ranged from 4 to 7 mm and median weekly differences from 4 to 8 mm. 90% of daily differences were between 9 and 16 mm and 90% of weekly differences between 11 and 19 mm. ICC values were found on average across sensors and gait parameters as 0.73 (ranging from 0.40 to 0.92 across parameters) for daily repeats and as 0.65 (0.27 to 0.91) for weekly repeats. MAIN LIMITATIONS Horses were of varying training and movement asymmetry levels, and no veterinary lameness examination was conducted. CONCLUSIONS Daily and weekly repeat gait assessments in this group of Thoroughbreds in training show lower ICC values than previously reported from within-day repeats in horses during lameness examinations. We recommend conducting repeatability studies for specific groups of horses when planning long-term studies aiming at identifying horses at risk of injury.
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Affiliation(s)
- M F Sepulveda Caviedes
- Department of Clinical Science and Services and Structure and Motion Lab, The Royal Veterinary College, Hatfield, Hertfordshire, UK
| | - B S Forbes
- Singapore Turf Club, Singapore, Singapore
| | - T Pfau
- Department of Clinical Science and Services and Structure and Motion Lab, The Royal Veterinary College, Hatfield, Hertfordshire, UK
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Pfau T, Noordwijk K, Sepulveda Caviedes MF, Persson‐Sjodin E, Barstow A, Forbes B, Rhodin M. Head, withers and pelvic movement asymmetry and their relative timing in trot in racing Thoroughbreds in training. Equine Vet J 2018; 50:117-124. [PMID: 28548349 PMCID: PMC5724686 DOI: 10.1111/evj.12705] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 05/16/2017] [Indexed: 11/27/2022]
Abstract
BACKGROUND Horses show compensatory head movement in hindlimb lameness and compensatory pelvis movement in forelimb lameness but little is known about the relationship of withers movement symmetry with head and pelvic asymmetry in horses with naturally occurring gait asymmetries. OBJECTIVES To document head, withers and pelvic movement asymmetry and timing differences in horses with naturally occurring gait asymmetries. STUDY DESIGN Retrospective analysis of gait data. METHODS Head, withers and pelvic movement asymmetry and timing of displacement minima and maxima were quantified from inertial sensors in 163 Thoroughbreds during trot-ups on hard ground. Horses were divided into 4 subgroups using the direction of head and withers movement asymmetry. Scatter plots of head vs. pelvic movement asymmetry illustrated how the head-withers relationship distinguishes between contralateral and ipsilateral head-pelvic movement asymmetry. Independent t test or Mann-Whitney U test (P<0.05) compared pelvic movement asymmetry and timing differences between groups. RESULTS The relationship between head and withers asymmetry (i.e. same sided or opposite sided asymmetry) predicts the relationship between head and pelvic asymmetry in 69-77% of horses. Pelvic movement symmetry was significantly different between horses with same sign vs. opposite sign of head-withers asymmetry (P<0.0001). Timing of the maximum head height reached after contralateral ('sound') stance was delayed compared to withers (P = 0.02) and pelvis (P = 0.04) in horses with contralateral head-withers asymmetry. MAIN LIMITATIONS The clinical lameness status of the horses was not investigated. CONCLUSION In the Thoroughbreds with natural gait asymmetries investigated here, the direction of head vs. withers movement asymmetry identifies the majority of horses with ipsilateral and contralateral head and pelvic movement asymmetries. Withers movement should be further investigated for differentiating between forelimb and hindlimb lame horses. Horses with opposite sided head and withers asymmetry significantly delay the upward movement of the head after 'sound' forelimb stance.
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Affiliation(s)
- T. Pfau
- Department of Clinical Science and ServicesRoyal Veterinary CollegeLondonUK
- Structure and Motion LaboratoryRoyal Veterinary CollegeLondonUK
| | - K. Noordwijk
- Structure and Motion LaboratoryRoyal Veterinary CollegeLondonUK
| | - M. F. Sepulveda Caviedes
- Department of Clinical Science and ServicesRoyal Veterinary CollegeLondonUK
- Structure and Motion LaboratoryRoyal Veterinary CollegeLondonUK
| | - E. Persson‐Sjodin
- Department of Clinical SciencesSwedish University of Agricultural SciencesUppsalaSweden
| | - A. Barstow
- Department of Clinical Science and ServicesRoyal Veterinary CollegeLondonUK
- Structure and Motion LaboratoryRoyal Veterinary CollegeLondonUK
| | - B. Forbes
- Singapore Turf ClubSingaporeSingapore
| | - M. Rhodin
- Department of Clinical SciencesSwedish University of Agricultural SciencesUppsalaSweden
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Olsen E, FouchÉ N, Jordan H, Pfau T, Piercy RJ. Kinematic discrimination of ataxia in horses is facilitated by blindfolding. Equine Vet J 2017; 50:166-171. [DOI: 10.1111/evj.12737] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 08/05/2017] [Indexed: 11/27/2022]
Affiliation(s)
- E. Olsen
- Structure and Motion Laboratory The Royal Veterinary College London UK
- Cornell University College of Veterinary Medicine Ithaca New York USA
| | - N. FouchÉ
- Swiss Institute of Equine Medicine (ISME) Vetsuisse‐Faculty University of Bern and Agroscope Berne Switzerland
| | - H. Jordan
- Structure and Motion Laboratory The Royal Veterinary College London UK
| | - T. Pfau
- Structure and Motion Laboratory The Royal Veterinary College London UK
| | - R. J. Piercy
- Department of Clinical Sciences and Services The Royal Veterinary College London UK
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Weeren PR, Pfau T, Rhodin M, Roepstorff L, Serra Bragança F, Weishaupt MA. Do we have to redefine lameness in the era of quantitative gait analysis? Equine Vet J 2017; 49:567-569. [DOI: 10.1111/evj.12715] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- P. R. Weeren
- Department of Equine Sciences Utrecht University Utrecht the Netherlands
| | - T. Pfau
- Department of Clinical Science and Services The Royal Veterinary College University of London Hatfield UK
| | - M. Rhodin
- Department of Clinical Sciences Swedish University of Agricultural Sciences Uppsala Sweden
| | - L. Roepstorff
- Department of Clinical Sciences Swedish University of Agricultural Sciences Uppsala Sweden
| | - F. Serra Bragança
- Department of Equine Sciences Utrecht University Utrecht the Netherlands
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