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Development, validation and clinical utility of short-term adverse-effects of electroconvulsive therapy (SAVE) checklist. Psychiatry Res 2024; 335:115839. [PMID: 38503006 DOI: 10.1016/j.psychres.2024.115839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 02/27/2024] [Accepted: 03/03/2024] [Indexed: 03/21/2024]
Abstract
Electroconvulsive therapy (ECT) is one of the most effective treatments in psychiatry. However, it has many cognitive and non-cognitive adverse effects (AEs). There are lacunae in the literature on systematic assessment of non-cognitive AEs. There is a need for a standard, comprehensive and specific clinical tool to evaluate this. Hence, a checklist of short-term AEs of ECT (SAVE) with a 2-phase assessment was developed. Content validation was done using 15 experts' ratings and predefined content validity ratio and index (CVR and CVI) in a two-stage modified Delphi method. The checklist had a good CVR and CVI with a final tool of 39 items. The tool was sensitive and identified the non-cognitive AEs after ECT. Cardiovascular and musculoskeletal systems displayed the highest incidence. Many participants exhibited delayed recovery in orientation, gait, and stance, highlighting a necessity for meticulous monitoring. SAVE is the first standardised tool to assess short-term ECT-related AEs systematically. This checklist likely identifies clinically significant incidences of adverse effects. Its regular use may enhance the safety of ECT and patient comfort by supporting early identification and intervention for AEs. However, given the transient nature of AEs, further studies are needed to determine their predictive validity for long-term consequences.
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Centre of pressure changes during stance but not during gait in young women after alcohol intoxication. PeerJ 2023; 11:e16511. [PMID: 38047022 PMCID: PMC10693231 DOI: 10.7717/peerj.16511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 11/02/2023] [Indexed: 12/05/2023] Open
Abstract
Background Women are underrepresented in research focused on alcohol (e.g., Brighton, Moxham & Traynor, 2016; DOI 10.1097/JAN.0000000000000136) despite the changing patterns of alcohol consumption, which has been increasing in women in recent decades. The purpose of this study was to analyse the relationship between habitual alcohol consumption and centre of pressure (CoP) parameters during stance and gait while intoxicated by alcohol. Methods Thirty women (24.39 ± 2.93 years) participated in this study. All participants were asked to answer the AUDIT questionnaire. Stance and gait analysis were repeated under two conditions on a Zebris platform (FDM GmbH; Munich, Germany): when the participants were sober (0.00% breath alcohol concentration, BrAC) and when they were in an intoxicated state (0.11% BrAC). Participants were divided by their AUDIT score into a low-risk alcohol consumption group (n = 15; AUDIT score: 3 to 6) and a hazardous alcohol consumption group (n = 15; AUDIT score: 7 to 13). Results No statistical difference was observed in stance and gait parameters when comparing the low-risk and hazardous groups under 0.00% BrAC and 0.11% BrAC conditions. A statistically significant difference was observed when comparing 0.00% BrAC and 0.11% BrAC conditions within each group. This significant difference was found in CoP path length and CoP average velocity during quiet stance. However, no statistically significant differences were observed in CoP parameters during gait. An alcohol intoxication of 0.11% BrAC was not sufficient to cause statistically significant impairments in butterfly parameters of gait.
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A multilayered graph-based framework to explore behavioural phenomena in social media conversations. Int J Med Inform 2023; 179:105236. [PMID: 37776669 DOI: 10.1016/j.ijmedinf.2023.105236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 08/18/2023] [Accepted: 09/24/2023] [Indexed: 10/02/2023]
Abstract
OBJECTIVE Social media is part of current health communications. This research aims to delve into the effects of social contagion, biased assimilation, and homophily in building and changing health opinions on social media. MATERIALS AND METHODS Conversations about COVID-19 vaccination on English and Spanish Twitter are the case studies. A new multilayered graph-based framework supports the integrated analysis of content similarity within and across posts, users, and conversations to interpret contrasting and confluent user stances. Deep learning models are applied to infer stance. Graph centrality and homophily scores support the interpretation of information reproduction. RESULTS The results show that semantically related English posts tend to present a similar stance about COVID-19 vaccination (rstance = 0.51) whereas Spanish posts are more heterophilic (rstance = 0.38). Neither case showed evidence of homophily regarding user influence or vaccine hashtags. Graph filters for Pfizer and Astrazeneca with a similarity threshold of 0.85 show stance homophily in English scenarios (i.e. rstance = 0.45 and rstance = 0.58, respectively) and small homophily in Spanish scenarios (i.e. r = 0.12 and r = 0.3, respectively). Highly connected users are a minority and are not socially influential. Spanish conversations showed stance homophily, i.e. most of the connected conversations promote vaccination (rstance = 0.42), whereas English conversations are more likely to offer contrasting stances. CONCLUSION The methodology proposed for quantifying the impact of natural and intentional social behaviours in health information reproduction can be applied to any of the main social platforms and any given topic of conversation. Its effectiveness was demonstrated by two case studies describing English and Spanish demographic and sociocultural scenarios.
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Wake up New Zealand! Directives, politeness and stance in Twitter #Covid19NZ posts. JOURNAL OF PRAGMATICS 2022; 196:6-23. [PMID: 36569631 PMCID: PMC9758008 DOI: 10.1016/j.pragma.2022.05.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 04/26/2022] [Accepted: 05/03/2022] [Indexed: 06/06/2023]
Abstract
As Covid-19 made its way to the shores of Aotearoa New Zealand in 2020, Kiwis took to Twitter to share their experiences and opinions regarding both the virus and government responses. In this paper, we examine a corpus of 1001 tweets to see just how Twitter users utilize different linguistic and politeness strategies when sharing directives conveying stance toward government Covid-19 measures. While there has been research into the use of directives in spoken and written language, there has been little exploration of how directives are used in the language of Social Media. Often considered difficult to classify even in more traditional language genres, Twitter corpora pose additional challenges. We propose a strategy to identify and classify directives using syntactic and pragmatic features, and use this strategy to identify linguistic patterns of both in relation to stance toward government Covid-19 measures. While we find that the most prototypical directive within our corpus is largely consistent with previous definitions, we also find that tweeters exhibit a striking amount of variation in directive strategy, emphasizing the need for a nuanced approach to directive identification and classification. We further note trends in the directive strategies utilized by tweeters expressing different stances toward government measures.
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Abstract
A comprehensive mobility assessment goes beyond the orthopedic or neurologic examination for the localization of pathology. This assessment involves attention to the dog's posture and stance, a hands-on examination with special attention to soft tissue structures, and the performance of functional assessments. A comprehensive mobility assessment can guide advanced diagnostic testing as well as providing a foundation in the formulation of a successful treatment plan.
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Grammatical devices of stance in written academic English. Heliyon 2021; 7:e08463. [PMID: 34901507 PMCID: PMC8639430 DOI: 10.1016/j.heliyon.2021.e08463] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 10/07/2021] [Accepted: 11/18/2021] [Indexed: 11/26/2022] Open
Abstract
Stance is a feature of academic writing that refers to how writers interact and engage with their readers by means of linguistic devices. This study focuses on the grammatical devices—and semantic distinctions thereof—that are employed by academic writers of English to express stance in research article abstracts in the areas of applied linguistics (AL) and literature (L). To this end, a corpus of 120 research article abstracts (60 in the area of AL and another 60 in that of L) was built and analysed using SPSS and following Biber et al.’s (1999) framework of grammatical devices of stance. The abstracts were extracted from high-quality journals in the respective areas: Applied Linguistics and English: Journal of the English Association. Both are ISI journals and published by Oxford Academic Publishing. A mixed-method approach, applying quantitative and qualitative measures, was adopted to answer the two questions: How is stance grammatically expressed in AL research article abstracts and L research article abstracts, and How is the expression of stance in AL research article abstracts similar to/different from that in L ones? The findings are construed in light of theories of academic discourse and English for Academic Purposes (EAP). The results reveal that there are important similarities and differences in the extent to which and the means through which stance is expressed in AL research article abstracts and L research article abstracts. In particular, the findings show that both AL and L abstracts were similar in the most frequently used stance marker which is the stance complement clause. However, they were different in the frequency of use of other devices. The study provides insights into the ways academic writers express stance in various fields which better our ability to write research article abstracts.
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Evaluation of 3D vertebral and pelvic position by surface topography in asymptomatic females: presentation of normative reference data. J Orthop Surg Res 2021; 16:703. [PMID: 34863230 PMCID: PMC8642978 DOI: 10.1186/s13018-021-02843-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 11/15/2021] [Indexed: 11/18/2022] Open
Abstract
Background Deviations from a conventional physiologic posture are often a cause of complaint. According to current literature, the upright physiological spine posture exhibits inclinations in the sagittal plane but not in the coronal and transverse planes, but individual vertebral body positions of asymptomatic adults have rarely been described using surface topography. Therefore, this work aims to form a normative reference dataset for the thoracic and lumbar vertebral bodies and for the pelvis in all three planes in asymptomatic women. Methods In a prospective, cross-sectional, monocentric study, 100 pain-free asymptomatic women, aged 20–64 years were enrolled. Habitual standing positions of the trunk were measured using surface topography. Data were analyzed in all three planes. Age sub-analysis was: 1) ages ≤ 40 years and 2) ages ≥ 41 years. Two-sample t-tests were used for age comparisons of the vertebral bodies, vertebra prominence (VP)–L4, and global parameters. One-sample t-tests were used to test deviations from symmetrical zero positions of VP–L4. Results Coronal plane: on average, the vertebral bodies were tilted to the right between the VP and T4 (maximum: T2 − 1.8° ± 3.2), while between T6 and T11 they were tilted to the left (maximum: T7 1.1° ± 1.9). T5 and L2 were in a neutral position, overall depicting a mean right-sided lateral flexion from T2 to T7 (apex at T5). Sagittal plane: the kyphotic apex resided at T8 with − 0.5° ± 3.6 and the lumbar lordotic apex at L3 with − 2.1° ± 7.4. Transverse plane: participants had a mean vertebral body rotation to the right ranging from T6 to L4 (maximum: T11 − 2.2° ± 3.5). Age-specific differences were seen in the sagittal plane and had little effect on overall posture. Conclusions Asymptomatic female volunteers standing in a habitual posture displayed an average vertebral rotation and lateral flexion to the right in vertebral segments T2–T7. The physiological asymmetrical posture of women could be considered in spinal therapies. With regard to spinal surgery, it should be clarified whether an approximation to an absolutely symmetrical posture is desirable from a biomechanical point of view? This data set can also be used as a reference in clinical practice. Trial registration: This study was registered with WHO (INT: DRKS00010834) and approved by the responsible ethics committee at the Rhineland–Palatinate Medical Association (837.194.16). Supplementary Information The online version contains supplementary material available at 10.1186/s13018-021-02843-2.
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Metabolic testing does not alter di stance running lower body sagittal kinematics. Gait Posture 2020; 76:403-408. [PMID: 31935615 DOI: 10.1016/j.gaitpost.2020.01.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 11/18/2019] [Accepted: 01/02/2020] [Indexed: 02/02/2023]
Abstract
BACKGROUND Distance running fitness is commonly assessed using metabolic testing (MT). During MT, the runner must wear a mask that covers the nose and mouth. It is unclear if this increased challenge alters running kinematics and/or stride-to-stride variability (SSV). In this study we thoroughly assess the sagittal plane lower body joint angles. RESEARCH QUESTION Are there significant differences between standard treadmill running kinematics and those collected during MT? METHODS Twenty recreational runners participated (34.8 ± 10.0 years; 20+ miles per week). Six Vicon Bonita cameras were used to collect kinematic data (200 Hz). A metabolic cart (Parvo Medics TrueOne 2400) was used for heart rate (HR) collection and testing. Participants ran 4 × 4 min at preferred pace: 2 control runs (CON) and 2 MT runs. Ten strides were used to generate average stance and swing joint angle plots. The phase plots were compared for CON and MT and mean difference scores were calculated (to determine the kinematic change). SSV was determined by assessing the standard deviations among the 10 strides. Repeated measures ANOVA was used to test for significant differences among CON and MT trials. Reliability was assessed for 8 discrete joint angles using ICC analysis. RESULTS There were no significant differences between CON and MT for both the joint angle plot comparisons and SSV. For the discrete kinematic measures, ICC scores were strong (0.89-0.99) between CON and MT. During MT, there were slight increases (p < 0.01) in HR (145 ± 14 vs. 147 ± 14) and RPE (10.4 ± 1.5 vs. 11.4 ± 1.5). SIGNIFICANCE Results from this study support the validity of simultaneously conducting a kinematic and MT analysis. However, clinicians and performance coaches should be aware that 1) MT is slightly more physiologically demanding than CON and 2) approaches from this study can be used during individual assessments to confirm that kinematics are similar (between CON and MT).
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Appendicular skeleton of Protoceratops andrewsi (Dinosauria, Ornithischia): comparative morphology, ontogenetic changes, and the implications for non-ceratopsid ceratopsian locomotion. PeerJ 2019; 7:e7324. [PMID: 31367485 PMCID: PMC6657679 DOI: 10.7717/peerj.7324] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 06/19/2019] [Indexed: 11/20/2022] Open
Abstract
Protoceratops andrewsi is a well-known ceratopsian dinosaur from the Djadokhta Formation (Upper Cretaceous, Mongolia). Since the 1920s, numerous skeletons of different ontogenetic stages from hatchlings to adults, including fully articulated specimens, have been discovered, but the postcranial anatomy of Protoceratops has not been studied in detail. A new, mostly articulated subadult individual provides an excellent opportunity for us to comprehensively describe the anatomy of the limb skeleton, to compare to other ceratopsian dinosaurs, and to study the ontogenetic and intraspecific variation in this species. New data provided by the specimen shed light on the lifestyle of P. andrewsi. The young subadult individuals present an array of morphological characters intermediate between the bipedal Psittacosaurus and fully quadrupedal adult P. andrewsi. We compare these observations with a broad range of non-ceratopsid Neoceratopsia (of various locomotor adaptations) and Psittacosauridae (obligate bipeds), which gives us insight into the evolution of the skeletal characters informative for the postural change in ceratopsian dinosaurs.
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Influence of bone lesion location on femoral bone strength assessed by MRI-based finite-element modeling. Bone 2019; 122:209-217. [PMID: 30851438 PMCID: PMC6486650 DOI: 10.1016/j.bone.2019.03.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 02/22/2019] [Accepted: 03/05/2019] [Indexed: 12/21/2022]
Abstract
Currently, clinical determination of pathologic fracture risk in the hip is conducted using measures of defect size and shape in the stance loading condition. However, these measures often do not consider how changing lesion locations or how various loading conditions impact bone strength. The goal of this study was to determine the impact of defect location on bone strength parameters in both the sideways fall and stance-loading conditions. We recruited 20 female subjects aged 48-77 years for this study and performed MRI of the proximal femur. Using these images, we simulated 10-mm pathologic defects in greater trochanter, superior, middle, and inferior femoral head, superior, middle, and inferior femoral neck, and lateral, middle, and medial proximal diaphysis to determine the effect of defect location on change in bone strength by performing finite element analysis. We compared the effect of each osteolytic lesion on bone stiffness, strength, resilience, and toughness. For the sideways fall loading, defects in the inferior femoral head (12.21%) and in the greater trochanter (6.43%) resulted in the greatest overall reduction in bone strength. For the stance loading, defects in the mid femoral head (-7.91%) and superior femoral head (-7.82%) resulted in the greatest overall reduction in bone strength. Changes in stiffness, yield force, ultimate force, resilience, and toughness were not found to be significantly correlated between the sideways fall and stance-loading for the majority of defect locations, suggesting that calculations based on the stance-loading condition are not predictive of the change in bone strength experienced in the sideways fall condition. While stiffness was significantly related to yield force (R2 > 0.82), overall force (R2 > 0.59), and resilience (R2 > 0.55), in both, the stance-loading and sideways fall conditions for most defect locations, stiffness was not significantly related to toughness. Therefore, structure-dependent measure such as stiffness may not fully explain the post-yield measures, which depend on material failure properties. The data showed that MRI-based models have the sensitivity to determine the effect of pathologic lesions on bone strength.
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Axial reflexes are present in older subjects and may contribute to balance responses. Exp Brain Res 2018; 236:1031-1039. [PMID: 29417172 DOI: 10.1007/s00221-018-5193-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2017] [Accepted: 01/31/2018] [Indexed: 10/18/2022]
Abstract
We studied the response to axial taps (mini-perturbations) of a group of 13 healthy older subjects (mean age 63 ± 12 years, 7 females, 6 males), 12 of whom were also studied using larger applied (macro-) perturbations requiring active postural responses. The mini-perturbation consisted of a brief impulsive force produced by a mini-shaker applied to the trunk at the level of the shoulders and anteriorly at the upper sternum which was perceived as a tap. Acceleration, force platform, and EMG measurements were made. The average peak accelerations for the mini-perturbations were 108 mG (anterior) and - 78.9 mG (posterior). Responses overall were very similar to those previously reported for younger subjects: the perturbation evoked short latency responses in leg muscles, modulated by degree and direction of lean, and were largest for the muscle most relevant for the postural correction. The increases in the amplitude for the main agonist were greater than the increase in tonic activity. With both anterior and posterior lean, co-contraction responses were present. The size of the EMG response to the mini-perturbations correlated with the corresponding earliest EMG responses (0-100, 100-200 ms intervals) to the larger postural perturbations, timing which corresponds to balance responses. The balance responses evoked by the larger imposed postural perturbations may, therefore, receive a contribution through the reflex pathway mediating the axial tap responses, whose efferent limb appears to be the reticulospinal tract.
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Commentary on "Modelling knee flexion effects on joint power absorption and adduction moment". Knee 2017; 24:1256-1257. [PMID: 28793977 DOI: 10.1016/j.knee.2017.05.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 05/22/2017] [Indexed: 02/02/2023]
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Abstract
Balance stability correlates with cerebellar vermis volume. Furthermore, the cerebellum is involved in precise timing of motor processes by fine-tuning the sensorimotor integration. We tested the hypothesis that any cerebellar action in stance control and in timing of visuomotor integration for balance is impaired by continuous theta-burst stimulation (cTBS) of the vermis. Ten subjects stood quietly and underwent six sequences of 10-min acquisition of center of foot pressure (CoP) data after cTBS, sham stimulation, and no stimulation. Visual shifts from eyes closed (EC) to eyes open (EO) and vice versa were presented via electronic goggles. Mean anteroposterior and mediolateral CoP position and oscillation, and the time delay at which body sway changed after visual shift were calculated. CoP position under both EC and EO condition was not modified after cTBS. Sway path length was greater with EC than EO and increased in both visual conditions after cTBS. CoP oscillation was also larger with EC and increased under both visual conditions after cTBS. The delay at which body oscillation changed after visual shift was longer after EC to EO than EO to EC, but unaffected by cTBS. The time constant of decrease or increase of oscillation was longer in EC to EO shifts, but unaffected by cTBS. Functional inactivation of the cerebellar vermis is associated with increased sway. Despite this, cTBS does not detectably modify onset and time course of the sensorimotor integration process of adaptation to visual shifts. Cerebellar vermis normally controls oscillation, but not timing of adaptation to abrupt changes in stabilizing information.
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Gait adaptations following multiple-ligament knee reconstruction occur with altered knee kinematics during level walking. Knee Surg Sports Traumatol Arthrosc 2017; 25:1489-1499. [PMID: 27085367 DOI: 10.1007/s00167-016-4104-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 03/22/2016] [Indexed: 10/21/2022]
Abstract
PURPOSE The biomechanical behaviour of the knee following multiple-ligament reconstruction (MLKR) may play a role in the pathogenesis of post-traumatic osteoarthritis. The aim of this study was to compare three-dimensional knee kinematics and gait characteristics of MLKR patients to healthy controls during level walking. METHODS Three-dimensional optoelectronic motion capture during overground walking was performed on 16 patients with MLKR and a group of healthy controls matched individually to each patient for age, gender, height and weight. Three-dimensional knee angles were extracted from the weight acceptance and propulsion sub-phases of gait. Statistical analysis was performed using group-aggregated data, as well as for each patient-control pair using a single-case approach. RESULTS Although group analysis detected few differences, single-case analysis revealed significant differences for a proportion of patients for all dependent variables during weight acceptance and propulsion sub-phases of stance. These kinematic differences occurred in the context of reduced gait velocity, step length and cadence, as well as increased time spent in double support. CONCLUSION Patients with MLKR display abnormalities in knee kinematics during gait at an average of 4.5 years after surgery. The pattern of kinematic abnormalities appears individual specific and may not be related to differences in spatiotemporal gait characteristics. The current findings describe detailed functional outcomes of MLKR reconstruction at average medium-term follow-up that provide improved prognostic information for clinicians to counsel patients with these types of injuries.
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Gait changes in a line of mice artificially selected for longer limbs. PeerJ 2017; 5:e3008. [PMID: 28243533 PMCID: PMC5324776 DOI: 10.7717/peerj.3008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 01/20/2017] [Indexed: 11/20/2022] Open
Abstract
In legged terrestrial locomotion, the duration of stance phase, i.e., when limbs are in contact with the substrate, is positively correlated with limb length, and negatively correlated with the metabolic cost of transport. These relationships are well documented at the interspecific level, across a broad range of body sizes and travel speeds. However, such relationships are harder to evaluate within species (i.e., where natural selection operates), largely for practical reasons, including low population variance in limb length, and the presence of confounding factors such as body mass, or training. Here, we compared spatiotemporal kinematics of gait in Longshanks, a long-legged mouse line created through artificial selection, and in random-bred, mass-matched Control mice raised under identical conditions. We used a gait treadmill to test the hypothesis that Longshanks have longer stance phases and stride lengths, and decreased stride frequencies in both fore- and hind limbs, compared with Controls. Our results indicate that gait differs significantly between the two groups. Specifically, and as hypothesized, stance duration and stride length are 8–10% greater in Longshanks, while stride frequency is 8% lower than in Controls. However, there was no difference in the touch-down timing and sequence of the paws between the two lines. Taken together, these data suggest that, for a given speed, Longshanks mice take significantly fewer, longer steps to cover the same distance or running time compared to Controls, with important implications for other measures of variation among individuals in whole-organism performance, such as the metabolic cost of transport.
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Using horizontal heel displacement to identify heel strike instants in normal gait. Gait Posture 2015; 42:101-3. [PMID: 25907129 DOI: 10.1016/j.gaitpost.2015.03.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 03/19/2015] [Accepted: 03/23/2015] [Indexed: 02/02/2023]
Abstract
Heel strike instants are an important component of gait analyses, yet accurate detection can be difficult without a force plate. This paper presents two novel techniques for kinematic heel strike instant (kHSI) detection which examined maximal resultant horizontal heel displacement (HHD). Each of these HHD techniques calculates HHD from a selected reference location of either the stance ankle or stance heel to the swing heel. The proposed techniques, along with other previously established techniques, were validated against a 10N force plate threshold. Fifty-four healthy adults walked overground at both normal and fast speeds while wearing athletic shoes. The reported true and absolute errors were as low as 3.2 (4.4) and 5.7 (3.4)ms, respectively, across 8678kHSI when using the stance ankle as a reference, which significantly outperformed (p<0.0001) the established techniques. Gait speed was shown to have a significant effect (p<0.0001) on HHD-determined kHSI, as well as the three other techniques evaluated, highlighting the need for condition-specific identification of kHSI.
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Abstract
Background Timed single-leg-stance test (SLST) is widely used to assess postural control in the elderly. In Parkinson’s disease (PD), it has been shown that an SLST around 10 seconds or below may be a sensitive indicator of future falls. However, despite its role in fall risk, whether SLST times around 10 seconds marks a clinically important stage of disease progression has largely remained unexplored. Methods A cross-sectional study where 27 people with PD were recruited and instructed to undertake timed SLST for both legs was conducted. Disease motor impairment was assessed with the Unified Parkinson’s Disease Rating Scale Part 3 (UPDRS-III). Results This study found that: 1) the SLST in people with PD shows good test-retest reliability; 2) SLST values can be attributed to two non-overlapping clusters: a low (10.4 ± 6.3 seconds) and a high (47.6 ± 11.7 seconds) value SLST group; 3) only the low value SLST group can be considered abnormal when age-matched normative SLST data are taken into account for comparison; and 4) lower UPDRS-III motor performance, and the bradykinesia sub-score in particular, are only associated with the low SLST group. Conclusion These results lend further support that a low SLST time around 10 seconds marks a clinically important stage of disease progression with significant worsening of postural stability in PD.
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Accuracy and precision of gait events derived from motion capture in horses during walk and trot. J Biomech 2014; 47:1220-4. [PMID: 24529754 DOI: 10.1016/j.jbiomech.2013.12.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Revised: 10/28/2013] [Accepted: 12/16/2013] [Indexed: 11/30/2022]
Abstract
This study aimed to create an evidence base for detection of stance-phase timings from motion capture in horses. The objective was to compare the accuracy (bias) and precision (SD) for five published algorithms for the detection of hoof-on and hoof-off using force plates as the reference standard. Six horses were walked and trotted over eight force plates surrounded by a synchronised 12-camera infrared motion capture system. The five algorithms (A-E) were based on: (A) horizontal velocity of the hoof; (B) Fetlock angle and horizontal hoof velocity; (C) horizontal displacement of the hoof relative to the centre of mass; (D) horizontal velocity of the hoof relative to the Centre of Mass and; (E) vertical acceleration of the hoof. A total of 240 stance phases in walk and 240 stance phases in trot were included in the assessment. Method D provided the most accurate and precise results in walk for stance phase duration with a bias of 4.1% for front limbs and 4.8% for hind limbs. For trot we derived a combination of method A for hoof-on and method E for hoof-off resulting in a bias of -6.2% of stance in the front limbs and method B for the hind limbs with a bias of 3.8% of stance phase duration. We conclude that motion capture yields accurate and precise detection of gait events for horses walking and trotting over ground and the results emphasise a need for different algorithms for front limbs versus hind limbs in trot.
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