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Tseng SC, Cherry D, Ko M, Fisher SR, Furtado M, Chang SH. The effects of combined transcranial brain stimulation and a 4-week visuomotor stepping training on voluntary step initiation in persons with chronic stroke-a pilot study. Front Neurol 2024; 15:1286856. [PMID: 38450075 PMCID: PMC10915046 DOI: 10.3389/fneur.2024.1286856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 02/02/2024] [Indexed: 03/08/2024] Open
Abstract
Purpose Evidence suggests that transcranial direct current stimulation (tDCS) can enhance motor performance and learning of hand tasks in persons with chronic stroke (PCS). However, the effects of tDCS on the locomotor tasks in PCS are unclear. This pilot study aimed to: (1) determine aggregate effects of anodal tDCS combined with step training on improvements of the neural and biomechanical attributes of stepping initiation in a small cohort of persons with chronic stroke (PCS) over a 4-week training program; and (2) assess the feasibility and efficacy of this novel approach for improving voluntary stepping initiation in PCS. Methods A total of 10 PCS were randomly assigned to one of two training groups, consisting of either 12 sessions of VST paired with a-tDCS (n = 6) or sham tDCS (s-tDCS, n = 4) over 4 weeks, with step initiation (SI) tests at pre-training, post-training, 1-week and 1-month follow-ups. Primary outcomes were: baseline vertical ground reaction force (B-vGRF), response time (RT) to initiate anticipatory postural adjustment (APA), and the retention of B-VGRF and RT. Results a-tDCS paired with a 4-week VST program results in a significant increase in paretic weight loading at 1-week follow up. Furthermore, a-tDCS in combination with VST led to significantly greater retention of paretic BWB compared with the sham group at 1 week post-training. Clinical implications The preliminary findings suggest a 4-week VST results in improved paretic limb weight bearing (WB) during SI in PCS. Furthermore, VST combined with a-tDCS may lead to better retention of gait improvements (NCT04437251) (https://classic.clinicaltrials.gov/ct2/show/NCT04437251).
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Affiliation(s)
- Shih-Chiao Tseng
- Neuromechanics Laboratory, Department of Physical Therapy, University of Texas Medical Branch, Galveston, TX, United States
| | - Dana Cherry
- Neuromechanics Laboratory, Department of Physical Therapy, University of Texas Medical Branch, Galveston, TX, United States
| | - Mansoo Ko
- Neuromechanics Laboratory, Department of Physical Therapy, University of Texas Medical Branch, Galveston, TX, United States
| | - Steven R. Fisher
- Neuromechanics Laboratory, Department of Physical Therapy, University of Texas Medical Branch, Galveston, TX, United States
| | - Michael Furtado
- Department of Physical Therapy, University of North Texas Health Science Center at Fort Worth, Fort Worth, TX, United States
| | - Shuo-Hsiu Chang
- Neuromuscular Plasticity Laboratory, Department of Physical Medicine and Rehabilitation, University of Texas Health Science Center at Houston, Houston, TX, United States
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Estimating Running Ground Reaction Forces from Plantar Pressure during Graded Running. SENSORS 2022; 22:s22093338. [PMID: 35591027 PMCID: PMC9105722 DOI: 10.3390/s22093338] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 04/18/2022] [Accepted: 04/23/2022] [Indexed: 12/10/2022]
Abstract
Ground reaction forces (GRFs) describe how runners interact with their surroundings and provide the basis for computing inverse dynamics. Wearable technology can predict time−continuous GRFs during walking and running; however, the majority of GRF predictions examine level ground locomotion. The purpose of this manuscript was to predict vertical and anterior–posterior GRFs across different speeds and slopes. Eighteen recreationally active subjects ran on an instrumented treadmill while we collected GRFs and plantar pressure. Subjects ran on level ground at 2.6, 3.0, 3.4, and 3.8 m/s, six degrees inclined at 2.6, 2.8, and 3.0 m/s, and six degrees declined at 2.6, 2.8, 3.0, and 3.4 m/s. We estimated GRFs using a set of linear models and a recurrent neural network, which used speed, slope, and plantar pressure as inputs. We also tested eliminating speed and slope as inputs. The recurrent neural network outperformed the linear model across all conditions, especially with the prediction of anterior–posterior GRFs. Eliminating speed and slope as model inputs had little effect on performance. We also demonstrate that subject−specific model training can reduce errors from 8% to 3%. With such low errors, researchers can use these wearable−based GRFs to understand running performance or injuries in real−world settings.
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Osada Y, Motojima N, Kobayashi Y, Yamamoto S. Differences in mediolateral dynamic stability during gait initiation according to whether the non-paretic or paretic leg is used as the leading limb. PLoS One 2022; 17:e0267577. [PMID: 35476702 PMCID: PMC9045617 DOI: 10.1371/journal.pone.0267577] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 04/11/2022] [Indexed: 11/24/2022] Open
Abstract
We investigated mediolateral dynamic stability at first foot off and first initial contact during gait initiation according to whether the paretic or non-paretic leg was used as the leading limb. Thirty-eight individuals with stroke initiated gait with the paretic and non-paretic legs as the leading limb, and their movements were measured using a 3D motion analysis system. Margin of stability (i.e., the length between the extrapolated center of mass and lateral border of the stance foot) was used as an index of dynamic stability, with a large value indicating dynamic stability in the lateral direction. However, an excessively large margin of stability value (i.e., when the extrapolated center of mass is outside the medial border of the stance foot) indicates dynamic instability in the medial direction. Differences in the margin of stability between tasks were compared using the Wilcoxon signed-rank test. The minimum margin of stability was observed just before first foot off. When the non-paretic leg was used as the leading limb, the margin of stability tended to be excessively large at first foot off compared with when the paretic leg was used (p < 0.001). In other words, the extrapolated center of mass was outside the medial border of the paretic stance foot. In conclusion, lateral stability was achieved when using the non-paretic leading limb because the extrapolated center of mass was located outside the medial border of the stance foot. However, medial dynamic stability was lower for the non-paretic leading limb compared with the paretic leading limb.
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Affiliation(s)
- Yuji Osada
- Department of Health and Welfare Tokushima Bunri University, Tokushima, Japan
- * E-mail:
| | - Naoyuki Motojima
- Showa University School of Nursing and rehabilitation Science, Kanagawa, Japan
| | | | - Sumiko Yamamoto
- Graduate School, International University of Health & Welfare, Tokyo, Japan
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Osada Y, Motojima N, Kobayashi Y, Yamamoto S. Differences in paretic lower limb loading and fluidity in sit-to-walk according to selection of the leading limb in individuals with stroke. Clin Biomech (Bristol, Avon) 2022; 94:105639. [PMID: 35390670 DOI: 10.1016/j.clinbiomech.2022.105639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 03/23/2022] [Accepted: 03/29/2022] [Indexed: 02/07/2023]
Abstract
BACKGROUND Sit-to-walk is an asymmetric task that is challenging for individuals with stroke, and paretic limb loading at seat-off and movement fluidity may change according to whether the non-paretic or paretic leg is used as the leading limb. This study aimed to investigate differences in paretic limb loading and fluidity depending on whether the non-paretic limb or paretic limb was used as the leading limb. METHODS Thirty-eight individuals with stroke performed sit-to-walk with each leg as the leading limb, and their movements were measured using a 3D motion analysis system. The paired t-test or Wilcoxon signed-rank test was used to assess differences according to limb selection in paretic limb loading ratio at seat-off and fluidity (Fluidity Index: ratio of the lowest to peak forward velocity before first initial contact). FINDINGS Twenty-two of 38 participants preferred to use the paretic limb as the leading limb. When leading with the paretic limb, the paretic limb loading ratio was significantly larger (p = 0.002), and the Fluidity Index was lower (p = 0.007). INTERPRETATION Sit-to-walk with the paretic leading limb seems to be an adaptive movement because many participants preferred leading with the paretic limb. However, selection of the leading limb in sit-to-walk involves a biomechanical tradeoff between paretic limb loading at seat-off and movement fluidity in individuals with stroke. Use of the paretic leading limb requires loading capacity of this limb, and the non-paretic leading limb must have high balance ability to merge sit-to-stand and gait initiation.
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Affiliation(s)
- Yuji Osada
- Department of Health and Welfare, Tokushima Bunri University, 180 Nishihamahoji, Tokushima 770-8514, Japan.
| | - Naoyuki Motojima
- Showa University, School of Nursing and rehabilitation Science, 1865 Tokaichibacho, Midoriku, Yokohama, Kanagawa 226-8555, Japan
| | - Yosuke Kobayashi
- Nakaizu Rehabilitation Center, 1523-108 Hiekawa, Izu, Shizuoka 410-2507, Japan
| | - Sumiko Yamamoto
- Graduate School, International University of Health and Welfare, 4-1-26 Akasaka, Minato-ku, Tokyo 107-8402, Japan.
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Takahashi M, Nakajima T, Takakusaki K. Preceding Postural Control in Forelimb Reaching Movements in Cats. Front Syst Neurosci 2022; 15:792665. [PMID: 35115911 PMCID: PMC8805610 DOI: 10.3389/fnsys.2021.792665] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 12/02/2021] [Indexed: 11/17/2022] Open
Abstract
Postural control precedes the goal-directed movement to maintain body equilibrium during the action. Because the environment continuously changes due to one’s activity, postural control requires a higher-order brain function that predicts the interaction between the body and the environment. Here, we tried to elucidate to what extent such a preceding postural control (PPC) predictively offered a posture that ensured the entire process of the goal-directed movement before starting the action. For this purpose, we employed three cats, which we trained to maintain a four-leg standing posture on force transducers to reach the target by either forelimb. Each cat performed the task under nine target locations in front with different directions and distances. As an index of posture, we employed the center of pressure (CVP) and examined CVP positions when the cat started postural alteration, began to lift its paw, and reached the target. After gazing at the target, each cat started PPC where postural alteration was accompanied by a 20–35 mm CVP shift to the opposite side of the forelimb to be lifted. Then, the cat lifted its paw at the predicted CVP position and reached the forelimb to the target with a CVP shift of only several mm. Moreover, each cat had an optimal target location where the relationship between the cat and target minimized the difference in the CVP positions between the predicted and the final. In this condition, more than 80% of the predicted CVP positions matched the final CVP positions, and the time requiring the reaching movement was the shortest. By contrast, the forelimb reaching movement required a greater CVP shift and longer time when the target was far from the cat. In addition, the time during forelimb reaching showed a negative correlation with the speed of the CVP shift during the PPC. These results suggest that the visuospatial information, such as the body-environment interaction, contributes to the motor programming of the PPC. We conclude that the PPC ensures postural stability throughout the action to optimize the subsequent goal-directed movements. Impairments in these processes may disturb postural stability during movements, resulting in falling.
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Affiliation(s)
- Mirai Takahashi
- Department of Physiology, Division of Neuroscience, Asahikawa Medical University, Asahikawa, Japan
| | - Toshi Nakajima
- Department of Integrative Neuroscience, Faculty of Medicine, The University of Toyama, Toyama, Japan
| | - Kaoru Takakusaki
- Department of Physiology, Division of Neuroscience, Asahikawa Medical University, Asahikawa, Japan
- *Correspondence: Kaoru Takakusaki,
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Szczerbik E, Kalinowska M, Święcicka A, Graff K, Syczewska M. The impact of two weeks of traditional therapy supplemented with virtual reality on balance control in neurologically-impaired children and adolescents. J Bodyw Mov Ther 2021; 28:513-520. [PMID: 34776187 DOI: 10.1016/j.jbmt.2021.09.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 07/19/2021] [Accepted: 09/24/2021] [Indexed: 11/25/2022]
Abstract
BACKGROUND The aim of the study was to assess whether two weeks of therapy (traditional and VR) may improve balance in children and adolescents with neurological problems of different origins and whether the deterioration in gait dynamic balance showed by patient's ground reaction forces (GRF) determinates therapy effectiveness. METHODS 29 participants aged 9-17 attended traditional therapy supplemented by tailor-made games. Therapy comprised exercises improving balance, range of motion, posture control, proprioception, muscle strength. Biodex Balance System was used for main assessment before and after therapy in tests: Postural Stability, modified Clinical Test of Sensory Integration and Balance, and Limits of Stability. Participants underwent gait analysis before the therapy to determine GRF. An increased maximal lateral component or decreased maximal anterior component in the push-off phase taking place in both legs were regarded as deterioration. This enabled the division into two groups with and without such a deterioration. Results were compared between the groups before and within groups before and after therapy. RESULTS The precision of forward-backwards body sway improved most significantly in the group with decreased GRF and reached the level of the second group, who worsened antero-posterior repeatability during stance on an unstable surface with eyes open. CONCLUSION Two weeks of combined traditional and VR therapy tailored to patients' functional weakness positively influenced the balance of neurologically impaired children. The group with decreased gait dynamic balance improved the tasks, which were intensively trained in the games. The second group remained more spontaneous in the trained direction.
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Affiliation(s)
- Ewa Szczerbik
- Rehabilitation Department, The Children's Memorial Health Institute, Al. Dzieci Polskich 20, 04-730, Warsaw, Poland.
| | - Małgorzata Kalinowska
- Rehabilitation Department, The Children's Memorial Health Institute, Al. Dzieci Polskich 20, 04-730, Warsaw, Poland
| | - Anna Święcicka
- Rehabilitation Department, The Children's Memorial Health Institute, Al. Dzieci Polskich 20, 04-730, Warsaw, Poland
| | - Krzysztof Graff
- Rehabilitation Department, The Children's Memorial Health Institute, Al. Dzieci Polskich 20, 04-730, Warsaw, Poland
| | - Małgorzata Syczewska
- Rehabilitation Department, The Children's Memorial Health Institute, Al. Dzieci Polskich 20, 04-730, Warsaw, Poland
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Celestino ML, van Emmerik R, Barela JA, Gama GL, Barela AM. Intralimb gait coordination of individuals with stroke using vector coding. Hum Mov Sci 2019; 68:102522. [DOI: 10.1016/j.humov.2019.102522] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 08/14/2019] [Accepted: 09/17/2019] [Indexed: 10/25/2022]
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Delafontaine A, Vialleron T, Hussein T, Yiou E, Honeine JL, Colnaghi S. Anticipatory Postural Adjustments During Gait Initiation in Stroke Patients. Front Neurol 2019; 10:352. [PMID: 31057474 PMCID: PMC6478808 DOI: 10.3389/fneur.2019.00352] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Accepted: 03/22/2019] [Indexed: 12/03/2022] Open
Abstract
Prior to gait initiation (GI), anticipatory postural adjustments (GI-APA) are activated in order to reorganize posture, favorably for gait. In healthy subjects, the center of pressure (CoP) is displaced backward during GI-APA, bilaterally by reducing soleus activities and activating the tibialis anterior (TA) muscles, and laterally in the direction of the leading leg, by activating hip abductors. In post-stroke hemiparetic patients, TA, soleus and hip abductor activities are impaired on the paretic side. Reduction in non-affected triceps surae activity can also be observed. These may result in a decreased ability to execute GI-APA and to generate propulsion forces during step execution. A systematic review was conducted to provide an overview of the reorganization which occurs in GI-APA following stroke as well as of the most effective strategies for tailoring gait-rehabilitation to these patients. Sixteen articles were included, providing gait data from a total of 220 patients. Stroke patients show a decrease in the TA activity associated with difficulties in silencing soleus muscle activity of the paretic leg, a decreased CoP shift, lower propulsive anterior forces and a longer preparatory phase. Regarding possible gait-rehabilitation strategies, the selected studies show that initiating gait with the paretic leg provides poor balance. The use of the non-paretic as the leading leg can be a useful exercise to stimulate the paretic postural muscles.
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Affiliation(s)
- Arnaud Delafontaine
- CIAMS, Université Paris-Sud, Université Paris-Saclay, Orsay, France.,CIAMS, Université d'Orléans, Orléans, France
| | - Thomas Vialleron
- CIAMS, Université Paris-Sud, Université Paris-Saclay, Orsay, France.,CIAMS, Université d'Orléans, Orléans, France
| | | | - Eric Yiou
- CIAMS, Université Paris-Sud, Université Paris-Saclay, Orsay, France.,CIAMS, Université d'Orléans, Orléans, France
| | | | - Silvia Colnaghi
- Department of Public Health, Experimental and Forensic Medicine, University of Pavia, Pavia, Italy.,Laboratory of Neuro-otology and Neuro-ophthalmology, IRCCS Mondino Foundation, Pavia, Italy
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Marinho-Buzelli AR, Masani K, Rouhani H, Barela AM, Fernandes GTB, Verrier MC, Popovic MR. The influence of the aquatic environment on the center of pressure, impulses and upper and lower trunk accelerations during gait initiation. Gait Posture 2017; 58:469-475. [PMID: 28923661 DOI: 10.1016/j.gaitpost.2017.09.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 09/06/2017] [Accepted: 09/07/2017] [Indexed: 02/02/2023]
Abstract
Gait initiation is defined as the transition from stationary standing to steady-state walking. Despite the frequent use of therapy pools for training walking in early stages of rehabilitation, none have been reported on the effects of immersion on gait initiation. We aimed to analyze the center of pressure (COP) trajectories, the vertical and anteroposterior impulses and upper and lower trunk accelerations during anticipatory (APA) and execution phases of gait initiation. In the COP trajectory, the execution (EXE) phase was further subdivided in two phases: predominantly mediolateral (EXE1), and predominantly anteroposterior (EXE2). Able-bodied participants initiated gait while standing on a force plate and walked approximately 4 steps following a visual cue. The participants were wearing three inertial sensors placed on the lower and upper trunk, and on the stance shank. Individuals performed 10 trials each on land and in water, in two consecutive days. The lengths and velocities of COP trajectories increased in water compared to land during APA, while the COP length increased and the COP velocity reduced in water during EXE2. The anteroposterior impulses increased in water during EXE. Lower trunk acceleration was smaller in water while the upper trunk acceleration did not differ, resulting in the larger ratio of upper to lower trunk acceleration in water during EXE. Overall, immersion in water increases COP length during gait initiation, and reduces COP velocity during EXE2, indicating a new postural strategy in water. The aquatic medium may be favorable for individuals who need weight support, gradual resistance and a longer time to execute gait initiation.
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Affiliation(s)
- Andresa R Marinho-Buzelli
- Rehabilitation Sciences Institute, University of Toronto, 500 University Avenue, Toronto, ON, M5G 1V7, Canada; Toronto Rehabilitation Institute - University Health Network, Lyndhurst Centre, 520 Sutherland Drive, Toronto, ON, M4G 3V9, Canada.
| | - Kei Masani
- Toronto Rehabilitation Institute - University Health Network, Lyndhurst Centre, 520 Sutherland Drive, Toronto, ON, M4G 3V9, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street, Room 407, Toronto, ON, M5S 3G9, Canada.
| | - Hossein Rouhani
- Department of Mechanical Engineering, University of Alberta, Donadeo Innovation Centre for Engineering, 9211-116 Street NW, Room 10-368, Edmonton, AB, T6G 1H9, Canada.
| | - Ana M Barela
- Institute of Physical Activity and Sport Sciences, Cruzeiro do Sul University, Rua Galvão Bueno, 868, 13o. andar, Bloco B, Liberdade, Sao Paulo, SP, 01506-000, Brazil.
| | - Gustavo T B Fernandes
- Department of Mechanical Engineering, Federal University of Santa Catarina, Caixa Postal 476 - Campus Universitário - Trindade, 88040-900, Florianópolis, SC, Santa Catarina, Brazil.
| | - Mary C Verrier
- Rehabilitation Sciences Institute, University of Toronto, 500 University Avenue, Toronto, ON, M5G 1V7, Canada; Toronto Rehabilitation Institute - University Health Network, Lyndhurst Centre, 520 Sutherland Drive, Toronto, ON, M4G 3V9, Canada; Department of Physical Therapy, University of Toronto, 500 University Avenue, Toronto, ON, M5G 1V7, Canada.
| | - Milos R Popovic
- Rehabilitation Sciences Institute, University of Toronto, 500 University Avenue, Toronto, ON, M5G 1V7, Canada; Toronto Rehabilitation Institute - University Health Network, Lyndhurst Centre, 520 Sutherland Drive, Toronto, ON, M4G 3V9, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street, Room 407, Toronto, ON, M5S 3G9, Canada.
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The Effect of Diabetic Peripheral Neuropathy on Ground Reaction Forces during Straight Walking in Stroke Survivors. Rehabil Res Pract 2017; 2017:5280146. [PMID: 28491477 PMCID: PMC5401715 DOI: 10.1155/2017/5280146] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 03/23/2017] [Accepted: 03/26/2017] [Indexed: 11/18/2022] Open
Abstract
Purpose. The aim of this present study was to investigate the ground reaction forces (GRFs) alterations in stroke survivors with diabetic peripheral neuropathy (DPN). Methods. Ten stroke survivors with DPN, 10 stroke survivors without DPN, and 10 healthy controls with matched body weight between groups participated in this case-control cross-sectional study. Three-dimensional GRFs (anterior-posterior, medial-lateral, and vertical) were collected at a comfortable walking speed using the Nexus Vicon motion analysis system and force plate. The Kruskal–Wallis test was used to analyze GRFs parameters. Results. We found significant alterations of medial-lateral forces of the nonparetic side and vertical forces of the paretic side in stroke survivors with DPN compared to stroke survivors without DPN and healthy controls. In addition, there were smaller braking and lower propulsion peak in anterior-posterior forces, smaller magnitude of medial-lateral forces, and lower first and second peak of vertical forces in stroke survivors with DPN compared to stroke survivors without DPN and healthy controls. Conclusion. The study findings identified that GRFs were affected in stroke survivors with DPN on both the paretic and the nonparetic sides. Further investigations are warranted to explore the impact of DPN on the kinematics and muscle activity related to the gait performance in stroke survivors with DPN.
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Anand M, Seipel J, Rietdyk S. A modelling approach to the dynamics of gait initiation. J R Soc Interface 2017; 14:rsif.2017.0043. [PMID: 28275124 DOI: 10.1098/rsif.2017.0043] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Accepted: 02/13/2017] [Indexed: 11/12/2022] Open
Abstract
Gait initiation is an integral and complex part of human locomotion. In this paper, we present a novel compliant-leg model-based approach to understanding the key phases of initiation, the nature of the effective forces involved in initiation, and the importance of the anticipatory postural adjustments (APAs). The results demonstrate that in the presence of APAs, we observe a change in the characteristic of forcing required for initiation, and the energetic cost of gait initiation is also reduced by approximately 58%. APAs also result in biologically relevant leg landing angles and trajectories of motion. Furthermore, we find that a sublinear functional relationship with the velocity error from steady state predicts the required force, consistent with an open loop control law basis for gait initiation.
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Affiliation(s)
- Manish Anand
- School of Mechanical Engineering, Purdue University, 585 Purdue Mall, West Lafayette IN, USA
| | - Justin Seipel
- School of Mechanical Engineering, Purdue University, 585 Purdue Mall, West Lafayette IN, USA
| | - Shirley Rietdyk
- Department of Health and Kinesiology, Purdue University, 800 West Stadium Avenue, West Lafayette IN, USA
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Boehm WL, Gruben KG. Post-Stroke Walking Behaviors Consistent with Altered Ground Reaction Force Direction Control Advise New Approaches to Research and Therapy. Transl Stroke Res 2015; 7:3-11. [PMID: 26639659 DOI: 10.1007/s12975-015-0435-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 11/10/2015] [Indexed: 11/26/2022]
Abstract
Recovery of walking after stroke requires an understanding of how motor control deficits lead to gait impairment. Traditional therapy focuses on removing specific observable gait behaviors that deviate from unimpaired walking; however, those behaviors may be effective compensations for underlying problematic motor control deficits rather than direct effects of the stroke. Neurological deficits caused by stroke are not well understood, and thus, efficient interventions for gait rehabilitation likely remain unrealized. Our laboratory has previously characterized a post-stroke control deficit that yields a specific difference in direction of the ground reaction force (F, limb endpoint force) exerted with the hemiplegic limb of study participants pushing on both stationary and moving pedals while seated. That task was not dependent on F to retain upright posture, and thus, the task did not constrain F direction. Rather, the F direction was the product of neural preference. It is not known if this specific muscle coordination deficit causes the observed walking deviations, but if present during walking, the deficit would prevent upright posture unless counteracted by compensatory behaviors. Compensations are presented that mechanically counteract the F misdirection to allow upright posture. Those compensations are similar to behaviors observed in stroke patients. Based on that alignment between predictions of this theory and clinical observations, we theorize that post-stroke gait results from the attempt to compensate for the underlying F misdirection deficit. Limb endpoint force direction has been shown to be trainable in the paretic upper limb, making it a feasible goal in the lower limb. If this F misdirection theory is valid, these ideas have tremendous promise for advancing the field of post-stroke gait rehabilitation.
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Affiliation(s)
- Wendy L Boehm
- Department of Kinesiology and Biomedical Engineering, University of Wisconsin-Madison, 2000 Observatory Drive, Madison, WI, 53706, USA.
| | - Kreg G Gruben
- Department of Kinesiology and Biomedical Engineering, University of Wisconsin-Madison, 2000 Observatory Drive, Madison, WI, 53706, USA
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