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Ting LH, Gick B, Kesar TM, Xu J. Ethnokinesiology: towards a neuromechanical understanding of cultural differences in movement. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230485. [PMID: 39155720 DOI: 10.1098/rstb.2023.0485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 05/15/2024] [Accepted: 06/18/2024] [Indexed: 08/20/2024] Open
Abstract
Each individual's movements are sculpted by constant interactions between sensorimotor and sociocultural factors. A theoretical framework grounded in motor control mechanisms articulating how sociocultural and biological signals converge to shape movement is currently missing. Here, we propose a framework for the emerging field of ethnokinesiology aiming to provide a conceptual space and vocabulary to help bring together researchers at this intersection. We offer a first-level schema for generating and testing hypotheses about cultural differences in movement to bridge gaps between the rich observations of cross-cultural movement variations and neurophysiological and biomechanical accounts of movement. We explicitly dissociate two interacting feedback loops that determine culturally relevant movement: one governing sensorimotor tasks regulated by neural signals internal to the body, the other governing ecological tasks generated through actions in the environment producing ecological consequences. A key idea is the emergence of individual-specific and culturally influenced motor concepts in the nervous system, low-dimensional functional mappings between sensorimotor and ecological task spaces. Motor accents arise from perceived differences in motor concept topologies across cultural contexts. We apply the framework to three examples: speech, gait and grasp. Finally, we discuss how ethnokinesiological studies may inform personalized motor skill training and rehabilitation, and challenges moving forward.This article is part of the theme issue 'Minds in movement: embodied cognition in the age of artificial intelligence'.
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Affiliation(s)
- Lena H Ting
- Coulter Department of Biomedical Engineering at Georgia Tech and Emory, Georgia Institute of Technology, Atlanta, GA 30332, USA
- Department of Rehabilitation Medicine, Division of Physical Therapy, Emory University, Atlanta, GA 30322, USA
| | - Bryan Gick
- Department of Linguistics, The University British Columbia, Vancouver, BC V6T 1Z4, Canada
- Haskins Laboratories, Yale University, New Haven, CT 06520, USA
| | - Trisha M Kesar
- Department of Rehabilitation Medicine, Division of Physical Therapy, Emory University, Atlanta, GA 30322, USA
| | - Jing Xu
- Department of Kinesiology, The University of Georgia, Athens, GA 30602, USA
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Kaufmann P, Koller W, Wallnöfer E, Goncalves B, Baca A, Kainz H. Increased trial-to-trial similarity and reduced temporal overlap of muscle synergy activation coefficients manifest during learning and with increasing movement proficiency. Sci Rep 2024; 14:17638. [PMID: 39085397 PMCID: PMC11291506 DOI: 10.1038/s41598-024-68515-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 07/23/2024] [Indexed: 08/02/2024] Open
Abstract
Muscle synergy analyses are used to enhance our understanding of motor control. Spatially fixed synergy weights coordinate multiple co-active muscles through activation commands, known as activation coefficients. To gain a more comprehensive understanding of motor learning, it is essential to understand how activation coefficients vary during a learning task and at different levels of movement proficiency. Participants walked on a line, a beam, and learned to walk on a tightrope-tasks that represent different levels of proficiency. Muscle synergies were extracted from electromyography signals across all conditions and the number of synergies was determined by the knee-point of the total variance accounted for (tVAF) curve. The results indicated that the tVAF of one synergy decreased with task proficiency, with the tightrope task resulting in the highest tVAF compared to the line and beam tasks. Furthermore, with increasing proficiency and after a learning process, trial-to-trial similarity increased and temporal overlap of synergy activation coefficients decreased. Consequently, we propose that precise adjustment and refinement of synergy activation coefficients play a pivotal role in motor learning.
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Affiliation(s)
- Paul Kaufmann
- Department of Biomechanics, Kinesiology and Computer Science in Sport, Centre for Sport Science and University Sports, University of Vienna, Auf Der Schmelz 6a (USZ ||), 1150, Vienna, Austria
- Neuromechanics Research Group, Centre for Sport Science and University Sports, University of Vienna, Auf Der Schmelz 6a, 1150, Vienna, Austria
| | - Willi Koller
- Department of Biomechanics, Kinesiology and Computer Science in Sport, Centre for Sport Science and University Sports, University of Vienna, Auf Der Schmelz 6a (USZ ||), 1150, Vienna, Austria
- Neuromechanics Research Group, Centre for Sport Science and University Sports, University of Vienna, Auf Der Schmelz 6a, 1150, Vienna, Austria
| | - Elias Wallnöfer
- Department of Biomechanics, Kinesiology and Computer Science in Sport, Centre for Sport Science and University Sports, University of Vienna, Auf Der Schmelz 6a (USZ ||), 1150, Vienna, Austria
- Neuromechanics Research Group, Centre for Sport Science and University Sports, University of Vienna, Auf Der Schmelz 6a, 1150, Vienna, Austria
| | - Basilio Goncalves
- Department of Biomechanics, Kinesiology and Computer Science in Sport, Centre for Sport Science and University Sports, University of Vienna, Auf Der Schmelz 6a (USZ ||), 1150, Vienna, Austria
- Neuromechanics Research Group, Centre for Sport Science and University Sports, University of Vienna, Auf Der Schmelz 6a, 1150, Vienna, Austria
| | - Arnold Baca
- Department of Biomechanics, Kinesiology and Computer Science in Sport, Centre for Sport Science and University Sports, University of Vienna, Auf Der Schmelz 6a (USZ ||), 1150, Vienna, Austria
| | - Hans Kainz
- Department of Biomechanics, Kinesiology and Computer Science in Sport, Centre for Sport Science and University Sports, University of Vienna, Auf Der Schmelz 6a (USZ ||), 1150, Vienna, Austria.
- Neuromechanics Research Group, Centre for Sport Science and University Sports, University of Vienna, Auf Der Schmelz 6a, 1150, Vienna, Austria.
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Lu C, Xu X, Liu Y, Li D, Wang Y, Xian W, Chen C, Wei B, Tian J. An Embedded Electromyogram Signal Acquisition Device. SENSORS (BASEL, SWITZERLAND) 2024; 24:4106. [PMID: 39000885 PMCID: PMC11244330 DOI: 10.3390/s24134106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2024] [Revised: 06/11/2024] [Accepted: 06/18/2024] [Indexed: 07/16/2024]
Abstract
In this study, we design an embedded surface EMG acquisition device to conveniently collect human surface EMG signals, pursue more intelligent human-computer interactions in exoskeleton robots, and enable exoskeleton robots to synchronize with or even respond to user actions in advance. The device has the characteristics of low cost, miniaturization, and strong compatibility, and it can acquire eight-channel surface EMG signals in real time while retaining the possibility of expanding the channel. This paper introduces the design and function of the embedded EMG acquisition device in detail, which includes the use of wired transmission to adapt to complex electromagnetic environments, light signals to indicate signal strength, and an embedded processing chip to reduce signal noise and perform filtering. The test results show that the device can effectively collect the original EMG signal, which provides a scheme for improving the level of human-computer interactions and enhancing the robustness and intelligence of exoskeleton equipment. The development of this device provides a new possibility for the intellectualization of exoskeleton systems and reductions in their cost.
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Affiliation(s)
- Changjia Lu
- China Coal Research Institute, Beijing 100013, China
- Emergency Science Research Academy, China Coal Research Institute, Beijing 100013, China
| | - Xin Xu
- Emergency Science Research Academy, China Coal Research Institute, Beijing 100013, China
| | - Yingjie Liu
- Emergency Science Research Academy, China Coal Research Institute, Beijing 100013, China
| | - Dan Li
- Emergency Science Research Academy, China Coal Research Institute, Beijing 100013, China
| | - Yue Wang
- Emergency Science Research Academy, China Coal Research Institute, Beijing 100013, China
| | - Wenhao Xian
- Emergency Science Research Academy, China Coal Research Institute, Beijing 100013, China
| | - Changbing Chen
- Emergency Science Research Academy, China Coal Research Institute, Beijing 100013, China
| | - Baichun Wei
- School of Medicine and Health, Harbin Institute of Technology, Harbin 150001, China
| | - Jin Tian
- School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001, China
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Ye C, Saboksayr SS, Shaw W, Coats RO, Astill SL, Mateos G, Delis I. A tensor decomposition reveals ageing-induced differences in muscle and grip-load force couplings during object lifting. Sci Rep 2024; 14:13937. [PMID: 38886363 PMCID: PMC11183154 DOI: 10.1038/s41598-024-62768-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 05/21/2024] [Indexed: 06/20/2024] Open
Abstract
Do motor patterns of object lifting movements change as a result of ageing? Here we propose a methodology for the characterization of these motor patterns across individuals of different age groups. Specifically, we employ a bimanual grasp-lift-replace protocol with younger and older adults and combine measurements of muscle activity with grip and load forces to provide a window into the motor strategies supporting effective object lifts. We introduce a tensor decomposition to identify patterns of muscle activity and grip-load force ratios while also characterizing their temporal profiles and relative activation across object weights and participants of different age groups. We then probe age-induced changes in these components. A classification analysis reveals three motor components that are differentially recruited between the two age groups. Linear regression analyses further show that advanced age and poorer manual dexterity can be predicted by the coupled activation of forearm and hand muscles which is associated with high levels of grip force. Our findings suggest that ageing may induce stronger muscle couplings in distal aspects of the upper limbs, and a less economic grasping strategy to overcome age-related decline in manual dexterity.
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Affiliation(s)
- Chang Ye
- Department of Electrical and Computer Engineering, University of Rochester, Rochester, 14620, USA
| | - Seyed Saman Saboksayr
- Department of Electrical and Computer Engineering, University of Rochester, Rochester, 14620, USA
| | - William Shaw
- School of Biomedical Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Rachel O Coats
- School of Psychology, University of Leeds, Leeds, LS2 9JT, UK
| | - Sarah L Astill
- School of Biomedical Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Gonzalo Mateos
- Department of Electrical and Computer Engineering, University of Rochester, Rochester, 14620, USA.
| | - Ioannis Delis
- School of Biomedical Sciences, University of Leeds, Leeds, LS2 9JT, UK.
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Staring WHA, Zandvliet S, de Kam D, Solis-Escalante T, Geurts ACH, Weerdesteyn V. Age-related changes in muscle coordination patterns of stepping responses to recover from loss of balance. Exp Gerontol 2024; 191:112424. [PMID: 38604252 DOI: 10.1016/j.exger.2024.112424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 04/07/2024] [Accepted: 04/08/2024] [Indexed: 04/13/2024]
Abstract
INTRODUCTION Reactive stepping capacity to recover from a loss of balance declines with aging, which increases the risk of falling. To gain insight into the underlying mechanisms, we investigated whether muscle coordination patterns of reactive stepping differed between healthy young and older individuals. METHODS We performed a cross-sectional study between 15 healthy young and 14 healthy older adults. They recovered from 200 multidirectional platform translations that evoked reactive stepping responses. We determined spatiotemporal step variables and used muscle synergy analysis to characterize stance- and swing-leg muscle coordination patterns from the start of perturbation until foot landing. RESULTS We observed delayed step onsets in older individuals, without further spatiotemporal differences. Muscle synergy structure was not different between young and older individuals, but age-related differences were observed in the time-varying synergy activation patterns. In anterior-posterior directions, the older individuals demonstrated significantly enhanced early swing-leg synergy activation consistent with non-stepping behavior. In addition, around step onset they demonstrated increased levels of synergy coactivation (mainly around the ankle) in lateral and anterior directions, which did not appear to hamper foot clearance. CONCLUSION Although synergy structure was not affected by age, the delayed step onsets and the enhanced early synergy recruitment point at a relative bias towards non-stepping behavior in older adults. They may need more time for accumulating information on the direction of perturbation and making the corresponding sensorimotor transformations before initiating the step. Future work may investigate whether perturbation-based training improves these age-related deficits.
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Affiliation(s)
- Wouter H A Staring
- Department of Rehabilitation, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands.
| | - Sarah Zandvliet
- Department of Rehabilitation, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Digna de Kam
- Department of Rehabilitation, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Teodoro Solis-Escalante
- Department of Rehabilitation, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Alexander C H Geurts
- Department of Rehabilitation, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands; Department of Rehabilitation, Sint Maartenskliniek, Nijmegen, the Netherlands
| | - Vivian Weerdesteyn
- Department of Rehabilitation, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands; Department of Rehabilitation, Sint Maartenskliniek, Nijmegen, the Netherlands
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O'Neal SK, Miller SA, Eikenberry MC, Moore ES. A backward cycling programme for people with Parkinson's disease: a feasibility and preliminary results study. J Rehabil Med 2024; 56:jrm17738. [PMID: 38860715 PMCID: PMC11182036 DOI: 10.2340/jrm.v56.17738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 05/13/2024] [Indexed: 06/12/2024] Open
Abstract
OBJECTIVE To assess the feasibility of backward cycling for people with Parkinson's disease. Secondary objectives were to assess changes in gait and balance following a 6-week program. DESIGN A single-group prospective pre-test, post-test study with 1-month follow-up. SUBJECTS/PATIENTS Twenty-six people with Parkinson's disease (mean age: 69 (7.74) years, gender: 83% males, time since diagnosis: 6 (4.44) years). METHODS Participants pedaled backward on a stationary bicycle for 30 minutes at moderate intensity twice a week for 6 weeks. Feasibility was assessed by acceptability, suitability, and burden. Data collected at pre- and post-intervention with 1-month follow-up included backward stepping response variables, forward/backward gait variables, Mini-Balance Evaluation Systems Test (MBT), and 6 Minute Walk Test. RESULTS There was a high retention rate (95.8%) and adherence rate (100%) with one adverse event and minimal burden. Significant improvements were seen in step count and excursion distance during backward stepping responses, forward and backward gait velocity, forward step length, and the Mini-BESTest. CONCLUSION Backward cycling was a feasible intervention for people with Parkinson's disease, demonstrating low burden with high retention and adherence rates, and it is a safe exercise with the potential for benefits in gait and balance variables.
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Affiliation(s)
| | - Stephanie A Miller
- University of Indianapolis, Indianapolis, Indiana, USA
- Marian University, Indianapolis, IN, USA
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Kaufmann P, Zweier L, Baca A, Kainz H. Muscle synergies are shared across fundamental subtasks in complex movements of skateboarding. Sci Rep 2024; 14:12860. [PMID: 38834832 DOI: 10.1038/s41598-024-63640-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 05/30/2024] [Indexed: 06/06/2024] Open
Abstract
A common theory of motor control posits that movement is controlled by muscle synergies. However, the behavior of these synergies during highly complex movements remains largely unexplored. Skateboarding is a hardly researched sport that requires rapid motor control to perform tricks. The objectives of this study were to investigate three key areas: (i) whether motor complexity differs between skateboard tricks, (ii) the inter-participant variability in synergies, and (iii) whether synergies are shared between different tricks. Electromyography data from eight muscles per leg were collected from seven experienced skateboarders performing three different tricks (Ollie, Kickflip, 360°-flip). Synergies were extracted using non-negative matrix factorization. The number of synergies (NoS) was determined using two criteria based on the total variance accounted for (tVAF > 90% and adding an additional synergy does not increase tVAF > 1%). In summary: (i) NoS and tVAF did not significantly differ between tricks, indicating similar motor complexity. (ii) High inter-participant variability exists across participants, potentially caused by the low number of constraints given to perform the tricks. (iii) Shared synergies were observed in every comparison of two tricks. Furthermore, each participant exhibited at least one synergy vector, which corresponds to the fundamental 'jumping' task, that was shared through all three tricks.
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Affiliation(s)
- Paul Kaufmann
- Department of Biomechanics, Kinesiology and Computer Science in Sport, Centre for Sport Science and University Sports, University of Vienna, Auf der Schmelz 6a (USZ II), 1150, Vienna, Austria
- Neuromechanics Research Group, Centre for Sport Science and University Sports, University of Vienna, Vienna, Austria
| | - Lorenz Zweier
- Department of Biomechanics, Kinesiology and Computer Science in Sport, Centre for Sport Science and University Sports, University of Vienna, Auf der Schmelz 6a (USZ II), 1150, Vienna, Austria
- Neuromechanics Research Group, Centre for Sport Science and University Sports, University of Vienna, Vienna, Austria
| | - Arnold Baca
- Department of Biomechanics, Kinesiology and Computer Science in Sport, Centre for Sport Science and University Sports, University of Vienna, Auf der Schmelz 6a (USZ II), 1150, Vienna, Austria
| | - Hans Kainz
- Department of Biomechanics, Kinesiology and Computer Science in Sport, Centre for Sport Science and University Sports, University of Vienna, Auf der Schmelz 6a (USZ II), 1150, Vienna, Austria.
- Neuromechanics Research Group, Centre for Sport Science and University Sports, University of Vienna, Vienna, Austria.
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Khan T, Rizvi MR, Sharma A, Ahmad F, Hasan S, Uddin S, Sidiq M, Ammari A, Iqbal A, Alghadir AH. Assessing muscle energy technique and foam roller self-myofascial release for low back pain management in two-wheeler riders. Sci Rep 2024; 14:12144. [PMID: 38802553 PMCID: PMC11130120 DOI: 10.1038/s41598-024-62881-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 05/22/2024] [Indexed: 05/29/2024] Open
Abstract
Pain in the lower back is a major concern in today's era due to prolonged sitting in two-wheeler riders, mainly due to hamstring tightness. It also creates physical disability and impairment in activities of daily living. The study aimed to compare the efficacy of muscle energy technique (MET) and self-myofascial release (SMFR) using the foam roller on hamstring flexibility, dynamic balance, and physical disability amongst two-wheeler riders with chronic low back pain (LBP). Participants were randomized into two intervention groups, MET and SMFR using the envelope method, with each group having 20 participants. Hamstring flexibility and range of motion for knee extension and the lower back were assessed using the active knee extension test (AKE-L and AKE-R) and sit and reach test (SRT), while the dynamic balance was assessed by the star excursion balance test (SEBT) and physical disability by Roland-Morris Disability Questionnaire, (RMDQ). Measurements were taken at baseline and after 4 weeks of intervention. This study demonstrated that both SMFR using a foam roller and MET are effective in enhancing hamstring muscle flexibility, (SRT-F(1, 38) = 299.5, p < 0.001; AKE-R-F(1, 38) = 99.53, p < 0.001; AKE-L-F(1, 38) = 89.67, p < 0.001). Additionally, these techniques significantly improved dynamic balance in various directions, including anterior (ANT), anteromedial (AMED), medial (MED), posteromedial (PMED), posterior (POST), posterolateral (PLAT), lateral (LAT), and anterolateral (ALAT) directions (p < 0.01). Furthermore, there was a significant reduction in physical disability (RMDQ-F(1, 38) = 1307, p < 0.001), among two-wheeler riders suffering from chronic LBP. Compared to MET, SMFR using foam rollers was found to be more effective in enhancing hamstring flexibility, improving balance, and decreasing disability level on the RMDQ after 4 weeks.
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Affiliation(s)
- Tabassum Khan
- Department of Physiotherapy, Faculty of Allied Health Sciences, Manav Rachna International Institute of Research and Studies (MRIIRS), Faridabad, 121001, India
| | - Moattar Raza Rizvi
- School of Allied Health Sciences, Manav Rachna International Institute of Research and Studies (MRIIRS), Faridabad, 121001, India
| | - Ankita Sharma
- Department of Physiotherapy, Faculty of Allied Health Sciences, Manav Rachna International Institute of Research and Studies (MRIIRS), Faridabad, 121001, India
| | - Fuzail Ahmad
- Respiratory Care Department, College of Applied Sciences, AlMaarefa University, 13713, Riyadh, Saudi Arabia
| | - Shahnaz Hasan
- Department of Physical Therapy and Health Rehabilitation, College of Applied Medical Sciences, Majmaah University, 15431, Al-Majmaah, Saudi Arabia
| | - Shadab Uddin
- Department of Physical Therapy, Faculty of Applied Medical Sciences, Jazan University, Jazan, Kingdom of Saudi Arabia
| | - Mohammad Sidiq
- Department of Physiotherapy, School of Medical and Allied Health Sciences, Galgotias University, Greater Noida, Uttar Pradesh, India
| | - Areej Ammari
- Department of Medical Rehabilitation, Abu-Arish General Hospital, Jazan, Saudi Arabia
| | - Amir Iqbal
- Rehabilitation Research Chair, Department of Rehabilitation Sciences, College of Applied Medical Sciences, King Saud University, 11433, Riyadh, Saudi Arabia.
| | - Ahmad H Alghadir
- Rehabilitation Research Chair, Department of Rehabilitation Sciences, College of Applied Medical Sciences, King Saud University, 11433, Riyadh, Saudi Arabia
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Chen Y, Yang C, Côté JN. Few sex-specific effects of fatigue on muscle synergies in a repetitive pointing task. J Biomech 2024; 163:111905. [PMID: 38183760 DOI: 10.1016/j.jbiomech.2023.111905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 10/30/2023] [Accepted: 12/13/2023] [Indexed: 01/08/2024]
Abstract
Previous studies have identified some sex differences in how individual muscles change their activation during repetitive multi-joint arm motion-induced fatigue. However, little is known about how indicators of multi-muscle coordination change with fatigue in males and females. Fifty-six (29 females) asymptomatic young adults performed a repetitive, forward-backward pointing task until scoring 8/10 on a Borg CR10 scale while surface electromyographic activity of upper trapezius, anterior deltoid, biceps brachii, and triceps brachii was recorded. Activation coefficient, synergy structure, and relative weight of each muscle within synergies were calculated using the non-negative matrix factorization method. Two muscle synergies were extracted from the fatiguing task. The synergy structures were mostly preserved after fatigue, while the activation coefficients were altered. A significant Sex × Fatigue interaction effect showed more use of the anterior deltoid in males especially before fatigue in synergy 1 during shoulder stabilization (p = 0.04). As for synergy 2, it was characterized by variations in the relative weight of biceps, which was higher by 16 % in females compared to males (p = 0.04), and increased with fatigue (p = 0.03) during the elbow flexion acceleration phase and the deceleration phase of the backward pointing movement. Findings suggest that both sexes adapted to fatigue similarly, using fixed synergy structures, with alterations in synergy activation patterns and relative weights of individual muscles. Results support previous findings of an important role for the biceps and anterior deltoid in explaining sex differences in patterns of repetitive motion-induced upper limb fatigue.
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Affiliation(s)
- Yiyang Chen
- Department of Kinesiology and Physical Education, McGill University, 475 Pine Avenue West, Montreal, QC H2W 1S4, Canada; CRIR Research Centre, Jewish Rehabilitation Hospital, 3205 Alton-Goldbloom Place, Laval, QC H7V 1R2, Canada.
| | - Chen Yang
- Department of Kinesiology and Physical Education, McGill University, 475 Pine Avenue West, Montreal, QC H2W 1S4, Canada; CRIR Research Centre, Jewish Rehabilitation Hospital, 3205 Alton-Goldbloom Place, Laval, QC H7V 1R2, Canada; Max Nader Lab for Rehabilitation Technologies and Outcomes Research, Shirley Ryan AbilityLab, Chicago, IL 60611, United States
| | - Julie N Côté
- Department of Kinesiology and Physical Education, McGill University, 475 Pine Avenue West, Montreal, QC H2W 1S4, Canada; CRIR Research Centre, Jewish Rehabilitation Hospital, 3205 Alton-Goldbloom Place, Laval, QC H7V 1R2, Canada
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10
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Lee J. Characteristics of muscle synergy extracted using an autoencoder in patients with stroke during the curved walking in comparison with healthy controls. Gait Posture 2024; 107:225-232. [PMID: 37845133 DOI: 10.1016/j.gaitpost.2023.10.009] [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: 02/06/2022] [Revised: 10/04/2023] [Accepted: 10/06/2023] [Indexed: 10/18/2023]
Abstract
BACKGROUND AND OBJECTIVE This study investigated the spatial and temporal features of muscle synergy during two types of curved walking (CW), according to whether the analyzed legs were located on the outside (OCW) or inside (ICW) on the basis of the curve direction during CW, in patients with stroke. METHODS Thirteen patients with stroke and seven age-matched healthy controls participated in this study. Using the autoencoder technique, four muscle synergies were extracted from eight muscles of the paretic legs in patients with stroke and the dominant legs in healthy controls. Walking speed, variance accounted for (VAF) of the four synergies, and each synergy with the same number were compared. Pearson's correlation and activation peak timing calculation were used to identify spatial and temporal features, respectively. RESULTS Regarding walking speed in patients with stroke, ICW was significantly faster than OCW (P = 0.027). Regarding spatial features, muscle weighting values of patients with stroke in synergy 3 that were mainly involved in the early swing phase had the lowest similarity [r = 0.30] during OCW, and synergy 4 that was mainly involved in the late swing phase had the lowest similarity [r = 0.39] during ICW compared to the healthy group. Meanwhile, in terms of temporal features, activation peak timings of patients with stroke in synergy 1, which was mainly involved in the early stance phase, and synergy 2, which was mainly involved in the mid-late stance phase, were significantly delayed during OCW (P < .001, P = 0.003), while peak timings of synergy 1 and synergy 3 were delayed during ICW (P = .004, P = .002). SIGNIFICANCE Based on distinctive features of spatial synergy during the swing phase of CW and temporal synergy during the swing-stance transition phase of CW in patients with stroke in gait rehabilitation, specific approaches need to be considered depending on the curve direction and each gait phase.
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Affiliation(s)
- JaeHyuk Lee
- Department of Industry-University cooperation, Hanshin University, Gyeonggi-do, the Republic of Korea.
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11
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Essers JMN, Meijer K, Peters AA, Murgia A. The effects of facioscapulohumeral dystrophy and dynamic arm support on upper extremity muscle coordination in functional tasks. Neuromuscul Disord 2023; 33:651-659. [PMID: 36581526 DOI: 10.1016/j.nmd.2022.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 11/10/2022] [Accepted: 11/11/2022] [Indexed: 11/23/2022]
Abstract
This study's objective is to understand the effect of muscular weakness in persons with facioscapulohumeral dystrophy as well as the effect of a dynamic arm support on muscle coordination and activity performance, during activities of daily living. People with facioscapulohumeral dystrophy (n=12, 56.0±14.5 years) and healthy controls (n=12, 55.5±13.4 years) performed five simulated daily activity tasks, while unsupported and supported by the Gowing dynamic arm support. Surface electromyography, kinematics, and maximum force output were recorded. Outcomes were calculated for muscle coordination (muscle synergies), maximum muscle activity, movement performance indicators, and upper limb muscular weakness (maximum force output). Muscle coordination was altered and less consistent in persons with facioscapulohumeral dystrophy compared with healthy controls. The dynamic arm support alleviated muscle efforts and affected muscle coordination in both populations. While populations became more similar, the internal consistency of persons with facioscapulohumeral dystrophy remained unaffected and lower than that of healthy controls. Furthermore, the support affected movements' performance in both groups. The maximum force outputs were lower in persons with facioscapulohumeral dystrophy than controls. Muscle coordination differences were presumably the result of individual-specific in muscle weakness and compensatory strategies for dealing with gravity compensation and movement constraints.
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Affiliation(s)
- J M N Essers
- Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition & Translational Research in Metabolism, Maastricht University Medical Centre+ (MUMC+), Maastricht, The Netherlands.
| | - K Meijer
- Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition & Translational Research in Metabolism, Maastricht University Medical Centre+ (MUMC+), Maastricht, The Netherlands
| | - A A Peters
- Department of Rehabilitation Medicine, University of Groningen, University Medical Center Groningen (UMCG), Groningen, The Netherlands
| | - A Murgia
- Department of Human Movement Sciences, University of Groningen, University Medical Center Groningen (UMCG), Groningen, The Netherlands
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12
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Mulla DM, Keir PJ. Neuromuscular control: from a biomechanist's perspective. Front Sports Act Living 2023; 5:1217009. [PMID: 37476161 PMCID: PMC10355330 DOI: 10.3389/fspor.2023.1217009] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 06/21/2023] [Indexed: 07/22/2023] Open
Abstract
Understanding neural control of movement necessitates a collaborative approach between many disciplines, including biomechanics, neuroscience, and motor control. Biomechanics grounds us to the laws of physics that our musculoskeletal system must obey. Neuroscience reveals the inner workings of our nervous system that functions to control our body. Motor control investigates the coordinated motor behaviours we display when interacting with our environment. The combined efforts across the many disciplines aimed at understanding human movement has resulted in a rich and rapidly growing body of literature overflowing with theories, models, and experimental paradigms. As a result, gathering knowledge and drawing connections between the overlapping but seemingly disparate fields can be an overwhelming endeavour. This review paper evolved as a need for us to learn of the diverse perspectives underlying current understanding of neuromuscular control. The purpose of our review paper is to integrate ideas from biomechanics, neuroscience, and motor control to better understand how we voluntarily control our muscles. As biomechanists, we approach this paper starting from a biomechanical modelling framework. We first define the theoretical solutions (i.e., muscle activity patterns) that an individual could feasibly use to complete a motor task. The theoretical solutions will be compared to experimental findings and reveal that individuals display structured muscle activity patterns that do not span the entire theoretical solution space. Prevalent neuromuscular control theories will be discussed in length, highlighting optimality, probabilistic principles, and neuromechanical constraints, that may guide individuals to families of muscle activity solutions within what is theoretically possible. Our intention is for this paper to serve as a primer for the neuromuscular control scientific community by introducing and integrating many of the ideas common across disciplines today, as well as inspire future work to improve the representation of neural control in biomechanical models.
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13
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Wagner AR, Merfeld DM. A modified two-dimensional sensory organization test that assesses both anteroposterior and mediolateral postural control. FRONTIERS IN REHABILITATION SCIENCES 2023; 4:1166859. [PMID: 37284337 PMCID: PMC10239846 DOI: 10.3389/fresc.2023.1166859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 04/26/2023] [Indexed: 06/08/2023]
Abstract
Background The Sensory Organization Test (SOT) was designed to measure changes in postural control in response to unreliable visual and/or proprioceptive feedback. However, secondary to the manipulation of sensory cues in only the sagittal plane, the SOT is capable of only describing postural control in a single direction. The present study aimed to characterize postural responses to a modified SOT designed to concurrently challenge both anteroposterior and mediolateral postural control. Methods Twenty-one healthy adult volunteers (30.6 ± 10.2 years) completed the standard anteroposterior one-dimensional (1D) SOT, in addition to a modified SOT with the support surface sway-referenced to both anteroposterior and mediolateral postural sway (two-dimensional, 2D). Our primary analysis concerned a comparison of mediolateral, as well as anteroposterior postural sway measured during the standard one-dimensional (i.e., pitch tilt) and the novel two-dimensional (i.e., roll and pitch tilt) sway-referenced paradigms. Here, postural sway was quantified by calculating the root mean square distance (RMSD) of the center of pressure (CoP) during each trial. Results Our data showed that the 2D sway-referenced conditions yielded a selective increase in mediolateral postural sway relative to the standard 1D conditions for both wide (η2 = 0.66) and narrow (η2 = 0.78) stance conditions, with anteroposterior postural sway being largely unaffected (η2 = 0.001 to 0.103, respectively). The ratio between mediolateral postural sway in the sway-referenced conditions and postural sway in the corresponding stable support surface conditions was greater for the 2D (2.99 to 6.26 times greater) compared to 1D paradigms (1.25 to 1.84 times greater), consistent with a superior degradation of viable proprioceptive feedback in the 2D paradigm. Conclusion A modified 2D version of the SOT was shown to provide a greater challenge to mediolateral postural control relative to the standard 1D SOT protocol, putatively as a result of a superior capacity to degrade proprioceptive feedback in the mediolateral direction. Given these positive findings, future studies should investigate the clinical utility of this modified SOT as a means by which to better characterize sensory contributions to postural control in the presence of various sensorimotor pathologies, including vestibular hypofunction.
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Affiliation(s)
- Andrew R. Wagner
- Department of Otolaryngology—Head and Neck Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, United States
- School of Health and Rehabilitation Sciences, The Ohio State University, Columbus, OH, United States
| | - Daniel M. Merfeld
- Department of Otolaryngology—Head and Neck Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, United States
- School of Health and Rehabilitation Sciences, The Ohio State University, Columbus, OH, United States
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, United States
- Department Speech and Hearing Sciences, The Ohio State University, Columbus, OH, United States
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14
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Disse GD, Nandakumar B, Pauzin FP, Blumenthal GH, Kong Z, Ditterich J, Moxon KA. Neural ensemble dynamics in trunk and hindlimb sensorimotor cortex encode for the control of postural stability. Cell Rep 2023; 42:112347. [PMID: 37027302 DOI: 10.1016/j.celrep.2023.112347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 02/09/2023] [Accepted: 03/21/2023] [Indexed: 04/08/2023] Open
Abstract
The cortex has a disputed role in monitoring postural equilibrium and intervening in cases of major postural disturbances. Here, we investigate the patterns of neural activity in the cortex that underlie neural dynamics during unexpected perturbations. In both the primary sensory (S1) and motor (M1) cortices of the rat, unique neuronal classes differentially covary their responses to distinguish different characteristics of applied postural perturbations; however, there is substantial information gain in M1, demonstrating a role for higher-order computations in motor control. A dynamical systems model of M1 activity and forces generated by the limbs reveals that these neuronal classes contribute to a low-dimensional manifold comprised of separate subspaces enabled by congruent and incongruent neural firing patterns that define different computations depending on the postural responses. These results inform how the cortex engages in postural control, directing work aiming to understand postural instability after neurological disease.
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Affiliation(s)
- Gregory D Disse
- Neuroscience Graduate Group, University of California, Davis, Davis, CA 95616, USA; Biomedical Engineering, University of California, Davis, Davis, CA 95616, USA
| | | | - Francois P Pauzin
- Biomedical Engineering, University of California, Davis, Davis, CA 95616, USA
| | - Gary H Blumenthal
- School of Biomedical Engineering Science and Health Systems, Drexel University, Philadelphia, PA 19104, USA
| | - Zhaodan Kong
- Mechanical and Aerospace Engineering, University of California, Davis, Davis, CA 95616, USA
| | - Jochen Ditterich
- Neuroscience Graduate Group, University of California, Davis, Davis, CA 95616, USA; Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA 95616, USA
| | - Karen A Moxon
- Neuroscience Graduate Group, University of California, Davis, Davis, CA 95616, USA; Biomedical Engineering, University of California, Davis, Davis, CA 95616, USA.
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15
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Cano Porras D, Heimler B, Jacobs JV, Naor SK, Inzelberg R, Zeilig G, Plotnik M. Upward perturbations trigger a stumbling effect. Hum Mov Sci 2023; 88:103069. [PMID: 36871477 DOI: 10.1016/j.humov.2023.103069] [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: 04/21/2022] [Revised: 02/06/2023] [Accepted: 02/09/2023] [Indexed: 03/06/2023]
Abstract
BACKGROUND Vertical perturbations are one major cause of falling. Incidentally, while conducting a comprehensive study comparing effects of vertical versus horizontal perturbations, we commonly observed a stumbling-like response induced by upward perturbations. The present study describes and characterizes this stumbling effect. METHODS Fourteen individuals (10 male; 27 ± 4 yr) walked self-paced on a treadmill embedded in a moveable platform and synchronized to a virtual reality system. Participants experienced 36 perturbations (12 types). Here, we report only on upward perturbations. We determined stumbling based on visual inspection of recorded videos, and calculated stride time and anteroposterior, whole-body center of mass (COM) distance relative to the heel, i.e., COM-to-heel distance, extrapolated COM (xCOM) and margin of stability (MOS) before and after perturbation. RESULTS From 68 upward perturbations across 14 participants, 75% provoked stumbling. During the first gait cycle post-perturbation, stride time decreased in the perturbed foot and the unperturbed foot (perturbed = 1.004 s vs. baseline = 1.119 s and unperturbed = 1.017 s vs. baseline = 1.125 s, p < 0.001). In the perturbed foot, the difference was larger in stumbling-provoking perturbations (stumbling: 0.15 s vs. non-stumbling: 0.020 s, p = 0.004). In addition, the COM-to-heel distance decreased during the first and second gait cycles after perturbation in both feet (first cycle: 0.58 m, second cycle: 0.665 m vs. baseline: 0.72 m, p-values<0.001). During the first gait cycle, COM-to-heel distance was larger in the perturbed foot compared to the unperturbed foot (perturbed foot: 0.61 m vs. unperturbed foot: 0.55 m, p < 0.001). MOS decreased during the first gait cycle, whereas the xCOM increased during the second through fourth gait cycles post-perturbation (maximal xCOM at baseline: 0.5 m, second cycle: 0.63 m, third cycle: 0.66 m, fourth cycle: 0.64 m, p < 0.001). CONCLUSIONS Our results show that upward perturbations can induce a stumbling effect, which - with further testing - has the potential to be translated into balance training to reduce fall risk, and for method standardization in research and clinical practice.
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Affiliation(s)
- Desiderio Cano Porras
- Center of Advanced Technologies in Rehabilitation, Sheba Medical Center, Ramat Gan, Israel; Brightlands Institute for Smart Society-BISS, Maastricht University, Maastricht, the Netherlands
| | - Benedetta Heimler
- Center of Advanced Technologies in Rehabilitation, Sheba Medical Center, Ramat Gan, Israel
| | - Jesse V Jacobs
- Rehabilitation and Movement Science, University of Vermont, Burlington, VT, USA
| | - Shani Kimel Naor
- Center of Advanced Technologies in Rehabilitation, Sheba Medical Center, Ramat Gan, Israel
| | - Rivka Inzelberg
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel; Department of Neurology and Neurosurgery, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Gabriel Zeilig
- Department of Neurological Rehabilitation, Sheba Medical Center, Ramat Gan, Israel; Department of Physical and Rehabilitation Medicine, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; School of Health Professions, Ono Academic College, Kiryat Ono, Israel
| | - Meir Plotnik
- Center of Advanced Technologies in Rehabilitation, Sheba Medical Center, Ramat Gan, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel; Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
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16
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Changes in Trunk Muscle Activity during Unilateral Weight Bearing and Abnormal Postural Gait in Healthy Individuals. MEDICINA (KAUNAS, LITHUANIA) 2022; 58:medicina58121800. [PMID: 36557001 PMCID: PMC9785953 DOI: 10.3390/medicina58121800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 11/30/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022]
Abstract
Background and Objectives: Many people tend to carry their bags or baggage on only one side of their body. Due to smartphone use, people also tend to walk bent forward in a kyphotic posture. In this study, we aimed to assess trunk muscle activity changes due to weight-bearing, carried in the left or right hand, and using three different gait postures. Materials and Methods: We recruited 27 healthy participants (aged 19−75 years) with no history of LBP within the last 6 months before study participation. Electromyographic activities of the lower back and the abdominal muscles of the participants were evaluated using four-channel surface electromyography (EMG). Surface EMG recordings were obtained from four trunk muscles, including the flexor (rectus abdominis (RA), external oblique (EO)) and extensor muscles (lumbar erector spinae (LE), and the superficial lumbar multifidus (LM)), during unilateral weight-bearing tasks and with different gait postures (normal gait, with a sway back, and thoracic kyphosis). Results: In the “unilateral weight-bearing task”, there was a significant difference in the activity of all the trunk muscles between the weight-bearing limb side and the opposite side (p < 0.05). The activation of the left trunk muscle was greater than that of the right trunk muscle when the dumbbell was lifted using the right hand. The other side showed the same result. In the “gait posture task” performed by the participants using a sway-back posture, the RA and EO had a higher level of activity in the stance and swing phases compared with that in a neutral gait (p < 0.05). Moreover, in the participants with a thoracic kyphosis posture, the LE and LM had a higher level of activity compared with that in a neutral gait (p < 0.05). Conclusions: Our results indicate that abnormal gait posture and unilateral weight-bearing tasks may impair the balance of trunk muscles, increasing the incidence of LBP. However, further large-scale, prospective, controlled studies are warranted to corroborate our results.
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17
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Neuromuscular mechanisms of motor adaptation to repeated gait-slip perturbations in older adults. Sci Rep 2022; 12:19851. [PMID: 36400866 PMCID: PMC9674587 DOI: 10.1038/s41598-022-23051-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 10/25/2022] [Indexed: 11/19/2022] Open
Abstract
Individuals can rapidly develop adaptive skills for fall prevention after their exposure to the repeated-slip paradigm. However, the changes in neuromuscular control contributing to such motor adaptation remain unclear. This study investigated changes in neuromuscular control across different stages of slip-adaptation by examining muscle synergies during slip training. Electromyography signals during 24 repeated slip trials in gait were collected for 30 healthy older adults. Muscle synergies in no-adaptation (novel slip), early-adaptation (slip 6 to 8), and late-adaptation trials (slip 22 to 24) were extracted. The similarity between the recruited muscle synergies in these different phases was subsequently analyzed. Results showed that participants made significant improvements in their balance outcomes from novel slips to adapted slips. Correspondingly, there was a significant increase in the muscle synergy numbers from no-adaptation slips to the adapted slips. The participants retained the majority of muscle synergies (5 out of 7) used in novel slips post adaptation. A few new patterns (n = 8) of muscle synergies presented in the early-adaptation stage to compensate for motor errors due to external perturbation. In the late-adaptation stage, only 2 out of these 8 new synergies were retained. Our findings indicated that the central nervous system could generate new muscle synergies through fractionating or modifying the pre-existing synergies in the early-adaptation phase, and these synergies produce motor strategies that could effectively assist in recovery from the slip perturbation. During the late-adaptation phase, the redundant synergies generated in the early-adaptation phase get eliminated as the adaptation process progresses with repeated exposure to the slips, which further consolidates the slip adaptation. Our findings improved the understanding of the key muscle synergies involved in preventing backward balance loss and how neuromuscular responses adapt through repeated slip training, which might be helpful to design synergy-based interventions for fall prevention.
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18
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Dehaghani MR, Nourani A, Arjmand N. Effects of auxetic shoe on lumbar spine kinematics and kinetics during gait and drop vertical jump by a combined in vivo and modeling investigation. Sci Rep 2022; 12:18326. [PMID: 36316350 PMCID: PMC9622817 DOI: 10.1038/s41598-022-21540-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 09/28/2022] [Indexed: 11/06/2022] Open
Abstract
The present study examined the effects of auxetic shoes on the biomechanics of the spine, as compared to barefoot and conventional shoe conditions, during gait and drop vertical jump (DVJ) activities using a combined in vivo and musculoskeletal modeling approach. Motion and force-plate data as well as electromyographic (EMG) activities of select trunk muscles of 11 individuals were collected during foregoing activities. In DVJ activity, two main phases of first landing (FL) and second landing (SL) were studied. In the FL phase of DVJ noticeable alternations were observed when auxetic shoes were used. That is, compared to the conventional footwear condition, smaller EMG activities in extensor muscles (by ~ 16-29%, p < 0.001), smaller anterior-posterior (AP) distance between the center of pressure of ground reaction force and heel (by ~ 19%, p = 0.002), generally larger maximal hip, knee, and ankle flexion angles (p < 0.005) and finally smaller maximal L5-S1 compression force and maximal external moment (by ~ 12 and 8%, respectively, p < 0.001) were obtained by wearing auxetic shoes. Our results, therefore, indicate that using auxetic shoes can reduce load on the lumbar spine during high-demanding activities such as vertical jump and thus may decrease the musculoskeletal risk of injuries during these activities.
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Affiliation(s)
- M. Rahmani Dehaghani
- grid.412553.40000 0001 0740 9747Department of Mechanical Engineering, Sharif University of Technology, Tehran, 11155-9567 Iran
| | - Amir Nourani
- grid.412553.40000 0001 0740 9747Department of Mechanical Engineering, Sharif University of Technology, Tehran, 11155-9567 Iran
| | - N. Arjmand
- grid.412553.40000 0001 0740 9747Department of Mechanical Engineering, Sharif University of Technology, Tehran, 11155-9567 Iran
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19
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Inoue M, Furuki D, Takiyama K. Detecting task-relevant spatiotemporal modules and their relation to motor adaptation. PLoS One 2022; 17:e0275820. [PMID: 36206279 PMCID: PMC9543959 DOI: 10.1371/journal.pone.0275820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 09/25/2022] [Indexed: 11/16/2022] Open
Abstract
How does the central nervous system (CNS) control our bodies, including hundreds of degrees of freedom (DoFs)? A hypothesis to reduce the number of DoFs posits that the CNS controls groups of joints or muscles (i.e., modules) rather than each joint or muscle independently. Another hypothesis posits that the CNS primarily controls motion components relevant to task achievements (i.e., task-relevant components). Although the two hypotheses are examined intensively, the relationship between the two concepts remains unknown, e.g., unimportant modules may possess task-relevant information. Here, we propose a framework of task-relevant modules, i.e., modules relevant to task achievements, while combining the two concepts mentioned above in a data-driven manner. To examine the possible role of the task-relevant modules, we examined the modulation of the task-relevant modules in a motor adaptation paradigm in which trial-to-trial modifications of motor output are observable. The task-relevant modules, rather than conventional modules, showed adaptation-dependent modulations, indicating the relevance of task-relevant modules to trial-to-trial updates of motor output. Our method provides insight into motor control and adaptation via an integrated framework of modules and task-relevant components.
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Affiliation(s)
- Masato Inoue
- Department of Electrical Engineering and Computer Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo, Japan
| | - Daisuke Furuki
- Department of Electrical Engineering and Computer Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo, Japan
| | - Ken Takiyama
- Department of Electrical Engineering and Computer Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo, Japan
- * E-mail:
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20
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Wang S, Pai (Clive) YC, Bhatt T. Kinematic synergies in over-ground slip recovery outcomes: Distinct strategies or a single strategy? Gait Posture 2022; 95:270-276. [PMID: 33653642 PMCID: PMC8368075 DOI: 10.1016/j.gaitpost.2021.01.025] [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: 02/20/2020] [Revised: 01/25/2021] [Accepted: 01/28/2021] [Indexed: 02/02/2023]
Abstract
BACKGROUND After experiencing an unexpected slip perturbation, individuals' behavioral performance can be classified into three categories: recovery, feet-forward fall, and split fall. Researchers are uncertain whether these differences in slip outcomes are due to distinct strategies or part of a single strategy. RESEARCH QUESTION Whether older adults with different behavioral outcomes during their novel slip have different kinematic synergies? METHODS The kinematic synergies were extracted from segment angles in 87 participants using principal component analysis (PCA). The first two principal components (PC1 and PC2) in pre-slip, early-reactive, and late-reactive phases were compared across different slip outcomes. RESULTS Results showed that the kinematic synergies in pre-slip and early-reactive phases are highly consistent among the three outcomes (recovery, split fall, and feet-forward fall). For the late-reactive phase, both split falls and feet-forward falls showed different kinematics synergies from recoveries. SIGNIFICANCE Our findings indicated that a single strategy might be used for different slip outcomes in the pre-slip and early-reactive phases, while distinct strategies were used by fallers compared to recovered individuals. Specifically, larger trunk flexion in pre-slip phase, larger knee flexion and plantar flexion of the slipping limb in both early-reactive and late-reactive phase, and larger knee extension of the recovery limb in late-reactive phase would lower the fall risk. This study would help to assess the vulnerabilities in control strategy, according to which individualized treatment could be provided to reduce predisposition to specific types of falls.
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Affiliation(s)
| | | | - Tanvi Bhatt
- Corresponding author at: Department of Physical Therapy, 1919, W Taylor St, (M/C 898), University of Illinois at Chicago, Chicago, IL, 60612, United States. (T. Bhatt)
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21
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Associations Between Lower Limb Isometric Torque, Isokinetic Torque, and Explosive Force With Phases of Reactive Stepping in Young, Healthy Adults. J Appl Biomech 2022; 38:190-197. [PMID: 35580844 DOI: 10.1123/jab.2021-0028] [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: 01/27/2021] [Revised: 11/03/2021] [Accepted: 04/21/2022] [Indexed: 11/18/2022]
Abstract
This study aimed to determine the relationship between lower limb muscle strength and explosive force with force plate-derived timing measures of reactive stepping. Nineteen young, healthy adults responded to 6 perturbations using an anterior lean-and-release system. Foot-off, swing, and restabilization times were estimated from force plates. Peak isokinetic torque, isometric torque, and explosive force of the knee extensors/flexors and plantar/dorsiflexors were measured using isokinetic dynamometry. Correlations were run based on a priori hypotheses and corrected for the number of comparisons (Bonferroni) for each variable. Knee extensor explosive force was negatively correlated with swing time (r = -.582, P = .009). Knee flexor peak isometric torque also showed a negative association with restabilization time (r = -.459, P = .048); however, this was not statistically significant after correcting for multiple comparisons. There was no significant relationship between foot-off time and knee or plantar flexor explosive force (P > .025). These findings suggest that there may be utility to identifying specific aspects of reactive step timing when studying the relationship between muscle strength and reactive balance control. Exercise training aimed at improving falls risk should consider targeting specific aspects of muscle strength depending on specific deficits in reactive stepping.
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22
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Park S, Caldwell GE. Muscle synergies are modified with improved task performance in skill learning. Hum Mov Sci 2022; 83:102946. [PMID: 35334208 DOI: 10.1016/j.humov.2022.102946] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 02/09/2022] [Accepted: 03/16/2022] [Indexed: 11/04/2022]
Abstract
How do muscle synergies change as motor skills are learned? The purpose of this study was to investigate the relationship between synergy number and skill acquisition, and to examine learning-related changes in synergy structure and activation patterns. We performed muscle synergy analysis using non-negative matrix factorization to identify muscle synergies from activation patterns of ten major leg muscles before and after recreational cyclists learned a novel one-legged pedal force aiming task (Park, Van Emmerik, & Caldwell, 2021). Synergy number was defined as the smallest number of factors from the matrix factorization algorithm that could explain more than the predefined threshold values. Improvements in pedal force direction after practice occurred without a change in the number of muscle synergies (four), suggesting that task constraints (e.g. the need for smooth pedaling motion) in this novel targeting task may limit the CNS to the same number of muscle synergies before and after practice. Improved task performance while continuing to satisfy multiple biomechanical tasks was obtained with changes in structure (muscle weightings) for one synergy, and activation amplitudes without changes in timing or pattern for three synergies. In each crank cycle quadrant, multiple synergies were altered in either structure or activation amplitude, suggesting that the cooperative changes may be essential for improving task performance while producing a smooth pedaling motion. Changes in both synergy structure and activation levels could be muscle coordination strategies in motor skill learning.
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Affiliation(s)
- Sangsoo Park
- Department of Kinesiology, University of Massachusetts Amherst, Amherst, MA 01003, United States of America; College of Medicine, Korea University, Seoul 20841, South Korea.
| | - Graham E Caldwell
- Department of Kinesiology, University of Massachusetts Amherst, Amherst, MA 01003, United States of America
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23
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Saito H, Yokoyama H, Sasaki A, Kato T, Nakazawa K. Evidence for basic units of upper limb muscle synergies underlying a variety of complex human manipulations. J Neurophysiol 2022; 127:958-968. [PMID: 35235466 DOI: 10.1152/jn.00499.2021] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Manipulations require complex upper-limb movements in which the central nervous system (CNS) must deal with many degrees of freedom. Evidence suggests that the CNS utilizes motor primitives called muscle synergies to simplify the production of movements. However, the exact neural mechanism underlying muscle synergies to control a wide array of manipulations is not fully understood. Here, we tested whether there are basic units of muscle synergies that can explain a diverse range of manipulations. We measured the electromyographic activities of 20 muscles across the shoulder, elbow, and wrist and fingers during 24 manipulation tasks. As a result, non-negative matrix factorization identified nine basic units of muscle synergies derived from the upper limb muscles that are shared across all tasks. The high similarity between muscle synergies of each of the 24 tasks and various combinations of nine basic unit muscle synergies in a single and/or merging state provides evidence that the CNS flexibly selects and modifies the degree of contribution of the nine basic units of muscle synergies to overcome different mechanical demands of tasks.
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Affiliation(s)
- Hiroki Saito
- Graduate School of Arts and Sciences, Department of Life Sciences, The University of Tokyo, Tokyo, Japan.,Department of Physical Therapy, Tokyo University of Technology, Tokyo, Japan
| | - Hikaru Yokoyama
- Graduate School of Arts and Sciences, Department of Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Atsushi Sasaki
- Graduate School of Arts and Sciences, Department of Life Sciences, The University of Tokyo, Tokyo, Japan.,Japan Society for the Promotion of Science, Tokyo, Japan
| | - Tatsuya Kato
- Graduate School of Arts and Sciences, Department of Life Sciences, The University of Tokyo, Tokyo, Japan.,Japan Society for the Promotion of Science, Tokyo, Japan
| | - Kimitaka Nakazawa
- Graduate School of Arts and Sciences, Department of Life Sciences, The University of Tokyo, Tokyo, Japan
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24
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Spomer AM, Yan RZ, Schwartz MH, Steele KM. Synergies are minimally affected during emulation of cerebral palsy gait patterns. J Biomech 2022; 133:110953. [PMID: 35092908 PMCID: PMC8916095 DOI: 10.1016/j.jbiomech.2022.110953] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 12/22/2021] [Accepted: 01/04/2022] [Indexed: 10/19/2022]
Abstract
Muscle synergy analysis is commonly used to characterize motor control during dynamic tasks like walking. For clinical populations, such as children with cerebral palsy (CP), synergies are altered compared to nondisabled (ND) peers and have been associated with both function and treatment outcomes. However, the factors that contribute to altered synergies remain unclear. In particular, the extent to which synergies reflect altered biomechanics (e.g., changes in gait) or underlying neurologic injury is debated. To evaluate the effect that altered biomechanics have on synergies, we compared synergy complexity and structure while ND individuals (n = 14) emulated four common CP gait patterns (equinus, equinus-crouch, mild-crouch, and moderate crouch). Secondarily, we compared the similarity of ND synergies during emulation to synergies from a retrospective cohort of individuals with CP walking in similar gait patterns (n = 28 per pattern). During emulation, ND individuals recruited similar synergies as baseline walking. However, pattern-specific deviations in synergy activations and complexity emerged. In particular, equinus gait altered plantarflexor activation timing and reduced synergy complexity. Importantly, ND synergies during emulation were distinct from those observed in CP for all gait patterns. These results suggest that altered gait patterns are not primarily driving the changes in synergies observed in CP, highlighting the value of using synergies as a tool to capture patient-specific differences in motor control. However, they also highlight the sensitivity of both synergy activations and complexity to altered biomechanics, which should be considered when using these measures in clinical care.
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Affiliation(s)
- Alyssa M Spomer
- Department of Mechanical Engineering, University of Washington, Seattle, WA, USA.
| | - Robin Z Yan
- Department of Mechanical Engineering, University of Washington, Seattle, WA, USA
| | - Michael H Schwartz
- James R. Gage Center for Gait & Motion Analysis, Gillette Children's Specialty Healthcare, Saint Paul, MN, USA; University of Minnesota, Minneapolis, MN, USA
| | - Katherine M Steele
- Department of Mechanical Engineering, University of Washington, Seattle, WA, USA
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König M, Santuz A, Epro G, Werth J, Arampatzis A, Karamanidis K. Differences in muscle synergies among recovery responses limit inter-task generalisation of stability performance. Hum Mov Sci 2022; 82:102937. [PMID: 35217390 DOI: 10.1016/j.humov.2022.102937] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 01/24/2022] [Accepted: 02/13/2022] [Indexed: 11/28/2022]
Abstract
Generalisation of adaptations is key to effective stability control facing variety of postural threats during daily life activity. However, in a previous study we could demonstrate that adaptations to stability control do not necessarily transfer to an untrained motor task. Here, we examined the dynamic stability and modular organisation of motor responses to different perturbations (i.e. unpredictable gait-trip perturbations and subsequent loss of anterior stability in a lean-and-release protocol) in a group of young and middle-aged adults (n = 57; age range 19-53 years) to detect potential neuromotor factors limiting transfer of adaptations within the stability control system. We hypothesized that the motor system uses different modular organisation in recovery responses to tripping and lean-and-release, which may explain lack in positive transfer of adaptations in stability control. After eight trip-perturbations participants increased their dynamic stability during the first recovery step (p < 0.001), yet they showed no significant improvement to the untrained lean-and-release transfer task compared to controls who did not undergo the perturbation exposure (p = 0.44). Regarding the neuromuscular control of responses, lower number of synergies (3 vs. 4) was found for the lean-and-release compared to the gait-trip perturbation task, revealing profound differences in both the timing and function of the recruited muscles to match the biomechanical specificity of different perturbations. Our results provide indirect evidence that the motor system uses different modular organisation in diverse perturbation responses, what possibly inhibits inter-task generalisation of adaptations in stability control.
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Affiliation(s)
- Matthias König
- Sport and Exercise Science Research Centre, School of Applied Sciences, London South Bank University, SE1 0AA London, United Kingdom.
| | - Alessandro Santuz
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, 10117 Berlin, Germany; Berlin School of Movement Science, Humboldt-Universität zu Berlin, 10117 Berlin, Germany
| | - Gaspar Epro
- Sport and Exercise Science Research Centre, School of Applied Sciences, London South Bank University, SE1 0AA London, United Kingdom
| | - Julian Werth
- Sport and Exercise Science Research Centre, School of Applied Sciences, London South Bank University, SE1 0AA London, United Kingdom
| | - Adamantios Arampatzis
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, 10117 Berlin, Germany; Berlin School of Movement Science, Humboldt-Universität zu Berlin, 10117 Berlin, Germany
| | - Kiros Karamanidis
- Sport and Exercise Science Research Centre, School of Applied Sciences, London South Bank University, SE1 0AA London, United Kingdom
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The Existence of Shared Muscle Synergies Underlying Perturbed and Unperturbed Gait Depends on Walking Speed. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12042135] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Muscle synergy theory assumes that the central nervous system generates a wide range of complex motor outputs by recruiting muscle synergies with different strengths and timings. The current understanding is that a common set of muscle synergies underlies unperturbed as well as perturbed walking at self-selected speeds. However, it is not known whether this is the case for substantially slower walking. The aim of this study was to investigate whether a shared set of muscle synergies underlies balance recovery responses following inward- and outward-directed perturbations in the mediolateral direction at various perturbation onsets and walking speeds. Twelve healthy subjects walked at three walking speeds (0.4, 0.6, and 0.8 m/s) on a treadmill while perturbations were applied to the pelvis using the balance assessment robot. A set of sixteen EMG signals, i.e., eight muscles per leg, was measured and decomposed into muscle synergies and weighting curves using non-negative matrix factorization. The muscles included were left and right tibialis anterior, soleus, gastrocnemius medialis, gastrocnemius lateralis, rectus femoris, hamstring, gluteus medius, and gluteus maximus. In general, four muscle synergies were needed to adequately reconstruct the data. Muscle synergies were similar for unperturbed and perturbed walking at a high walking speed (0.8 m/s). However, the number of similar muscle synergies between perturbed and unperturbed walking was significantly lower for low walking speeds (0.4 and 0.6 m/s). These results indicate that shared muscle synergies underlying perturbed and unperturbed walking are less present during slow walking compared to fast walking.
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The association between motor modules and movement primitives of gait: A muscle and kinematic synergy study. J Biomech 2022; 134:110997. [DOI: 10.1016/j.jbiomech.2022.110997] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 01/28/2022] [Accepted: 02/08/2022] [Indexed: 12/26/2022]
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Sato Y, Kondo T, Shibata R, Nakamura M, Okano H, Ushiba J. Functional reorganization of locomotor kinematic synergies reflects the neuropathology in a mouse model of spinal cord injury. Neurosci Res 2021; 177:78-84. [PMID: 34921835 DOI: 10.1016/j.neures.2021.12.002] [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: 10/07/2021] [Revised: 12/14/2021] [Accepted: 12/14/2021] [Indexed: 11/27/2022]
Abstract
Spinal cord injury (SCI) disrupts motor commands to modular structures of the spinal cord, limiting the ability to walk. Evidence suggests that these modules are conserved across species from rodent to human and subserve adaptive walking by controlling coordinated joint movements (kinematic synergies). Since SCI causes uncoordinated joint movements of the lower limbs during walking, there may be a disorder of the modular structures that control them. To gain insights into this complex process, we recorded the kinematics of intact and SCI mice when walking on a treadmill and applied principal component analysis to extract kinematic synergies. Most SCI mice walked stably on the treadmill, but their kinematic synergies were generally different from those of intact mice. We classified the kinematic synergies of SCI mice into three groups based on the similarity of the extracted first three synergy components. We found that these three groups had different degrees of spinal cord damage. This suggests that differences in kinematic synergies reflect underlying SCI neuropathology. These results may help guide the development of different rehabilitation approaches and future physiological experiments to understand the mechanisms of motor control and recovery.
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Affiliation(s)
- Yuta Sato
- Graduate School of Science and Technology, Keio University, Kanagawa, Japan; Laboratory for Marmoset Neural Architecture, RIKEN Center for Brain Science, Saitama, Japan
| | - Takahiro Kondo
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
| | - Reo Shibata
- Department of Orhopaedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Masaya Nakamura
- Department of Orhopaedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Hideyuki Okano
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
| | - Junichi Ushiba
- Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University, Kanagawa, Japan.
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Stamenkovic A, Ting LH, Stapley PJ. Evidence for constancy in the modularity of trunk muscle activity preceding reaching: implications for the role of preparatory postural activity. J Neurophysiol 2021; 126:1465-1477. [PMID: 34587462 PMCID: PMC8782652 DOI: 10.1152/jn.00093.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 08/30/2021] [Accepted: 09/26/2021] [Indexed: 11/22/2022] Open
Abstract
Postural muscle activity precedes voluntary movements of the upper limbs. The traditional view of this activity is that it anticipates perturbations to balance caused by the movement of a limb. However, findings from reach-based paradigms have shown that postural adjustments can initiate center of mass displacement for mobility rather than minimize its displacement for stability. Within this context, altering reaching distance beyond the base of support would place increasing constraints on equilibrium during stance. If the underlying composition of anticipatory postural activity is linked to stability, coordination between muscles (i.e., motor modules) may evolve differently as equilibrium constraints increase. We analyzed the composition of motor modules in functional trunk muscles as participants performed multidirectional reaching movements to targets within and beyond the arm's length. Bilateral trunk and reaching arm muscle activity were recorded. Despite different trunk requirements necessary for successful movement, and the changing biomechanical (i.e., postural) constraints that accompany alterations in reach distance, nonnegative matrix factorization identified functional motor modules derived from preparatory trunk muscle activity that shared common features. Relative similarity in modular weightings (i.e., composition) and spatial activation profiles that reflect movement goals across tasks necessitating differing levels of trunk involvement provides evidence that preparatory postural adjustments are linked to the same task priorities (i.e., movement generation rather than stability).NEW & NOTEWORTHY Reaching within and beyond arm's length places different task constraints upon the required trunk motion necessary for successful movement execution. The identification of constant modular features, including functional muscle weightings and spatial tuning, lend support to the notion that preparatory postural adjustments of the trunk are tied to the same task priorities driving mobility, regardless of the future postural constraints.
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Affiliation(s)
- Alexander Stamenkovic
- Neural Control of Movement Laboratory, School of Medicine, Faculty of Science, Medicine & Health, University of Wollongong, Wollongong, New South Wales, Australia
- Department of Physical Therapy, College of Health Professions, Virginia Commonwealth University, Richmond, Virginia
| | - Lena H Ting
- Walter H. Coulter Department of Biomedical Engineering, Georgia Tech College of Engineering, Emory School of Medicine, Emory University, Atlanta, Georgia
- Division of Physical Therapy, Department of Rehabilitation Medicine, Emory School of Medicine, Emory University, Atlanta, Georgia
| | - Paul J Stapley
- Neural Control of Movement Laboratory, School of Medicine, Faculty of Science, Medicine & Health, University of Wollongong, Wollongong, New South Wales, Australia
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Mcdonald CG, Fregly BJ, O'Malley MK. Effect of Robotic Exoskeleton Motion Constraints on Upper Limb Muscle Synergies: A Case Study. IEEE Trans Neural Syst Rehabil Eng 2021; 29:2086-2095. [PMID: 34618674 DOI: 10.1109/tnsre.2021.3118591] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Evidence exists that changes in composition, timing, and number of muscle synergies can be correlated to functional changes resulting from neurological injury. These changes can also serve as an indicator of level of motor impairment. As such, synergy analysis can be used as an assessment tool for robotic rehabilitation. However, it is unclear whether using a rehabilitation robot to isolate limb movements during training affects the subject's muscle synergies, which would affect synergy-based assessments. In this case study, electromyographic (EMG) data were collected to analyze muscle synergies generated during single degree-of-freedom (DoF) elbow and wrist movements performed by a single healthy subject in a four DoF robotic exoskeleton. For each trial, the subject was instructed to move a single DoF from a neutral position out to a target and back while the remaining DoFs were held in a neutral position by either the robot (constrained) or the subject (unconstrained). Four factorization methods were used to calculate muscle synergies for both types of trials: concatenation, averaging, single trials, and bootstrapping. The number of synergies was chosen to achieve 90% global variability accounted for. Our preliminary results indicate that muscle synergy composition and timing were highly similar for constrained and unconstrained trials, though some differences between the four factorization methods existed. These differences could be explained by higher trial-to-trial EMG variability for the unconstrained trials. These results suggest that using a robotic exoskeleton to constrain limb movements during robotic training may not alter a subject's muscle synergies, at least for healthy subjects.
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Saito H, Yokoyama H, Sasaki A, Kato T, Nakazawa K. Flexible Recruitments of Fundamental Muscle Synergies in the Trunk and Lower Limbs for Highly Variable Movements and Postures. SENSORS (BASEL, SWITZERLAND) 2021; 21:6186. [PMID: 34577394 PMCID: PMC8472977 DOI: 10.3390/s21186186] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 09/08/2021] [Accepted: 09/13/2021] [Indexed: 11/16/2022]
Abstract
The extent to which muscle synergies represent the neural control of human behavior remains unknown. Here, we tested whether certain sets of muscle synergies that are fundamentally necessary across behaviors exist. We measured the electromyographic activities of 26 muscles, including bilateral trunk and lower limb muscles, during 24 locomotion, dynamic and static stability tasks, and we extracted the muscle synergies using non-negative matrix factorization. Our results show that 13 muscle synergies that may have unique functional roles accounted for almost all 24 tasks by combinations of single and/or merging of synergies. Therefore, our results may support the notion of the low dimensionality in motor outputs, in which the central nervous system flexibly recruits fundamental muscle synergies to execute diverse human behaviors. Further studies are required to validate the neural representation of the fundamental components of muscle synergies.
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Affiliation(s)
- Hiroki Saito
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan; (H.S.); (H.Y.); (A.S.); (T.K.)
- Department of Physical Therapy, Tokyo University of Technology, Ota, Tokyo 144-8535, Japan
| | - Hikaru Yokoyama
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan; (H.S.); (H.Y.); (A.S.); (T.K.)
| | - Atsushi Sasaki
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan; (H.S.); (H.Y.); (A.S.); (T.K.)
- Japan Society for the Promotion of Science, 5-3-1 Kojimachi, Chiyoda, Tokyo 102-0083, Japan
| | - Tatsuya Kato
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan; (H.S.); (H.Y.); (A.S.); (T.K.)
- Japan Society for the Promotion of Science, 5-3-1 Kojimachi, Chiyoda, Tokyo 102-0083, Japan
| | - Kimitaka Nakazawa
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan; (H.S.); (H.Y.); (A.S.); (T.K.)
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32
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Wei B, Ding Z, Yi C, Guo H, Wang Z, Zhu J, Jiang F. A Novel sEMG-Based Gait Phase-Kinematics-Coupled Predictor and Its Interaction With Exoskeletons. Front Neurorobot 2021; 15:704226. [PMID: 34447302 PMCID: PMC8384035 DOI: 10.3389/fnbot.2021.704226] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Accepted: 07/15/2021] [Indexed: 11/13/2022] Open
Abstract
The interaction between human and exoskeletons increasingly relies on the precise decoding of human motion. One main issue of the current motion decoding algorithms is that seldom algorithms provide both discrete motion patterns (e.g., gait phases) and continuous motion parameters (e.g., kinematics). In this paper, we propose a novel algorithm that uses the surface electromyography (sEMG) signals that are generated prior to their corresponding motions to perform both gait phase recognition and lower-limb kinematics prediction. Particularly, we first propose an end-to-end architecture that uses the gait phase and EMG signals as the priori of the kinematics predictor. In so doing, the prediction of kinematics can be enhanced by the ahead-of-motion property of sEMG and quasi-periodicity of gait phases. Second, we propose to select the optimal muscle set and reduce the number of sensors according to the muscle effects in a gait cycle. Finally, we experimentally investigate how the assistance of exoskeletons can affect the motion intent predictor, and we propose a novel paradigm to make the predictor adapt to the change of data distribution caused by the exoskeleton assistance. The experiments on 10 subjects demonstrate the effectiveness of our algorithm and reveal the interaction between assistance and the kinematics predictor. This study would aid the design of exoskeleton-oriented motion-decoding and human–machine interaction methods.
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Affiliation(s)
- Baichun Wei
- School of Computer Science and Technology, Harbin Institute of Technology, Harbin, China.,Pengcheng Laboratory, Shenzhen, China
| | - Zhen Ding
- School of Mechatronics Engineering, Harbin Institute of Technology, Harbin, China
| | - Chunzhi Yi
- School of Mechatronics Engineering, Harbin Institute of Technology, Harbin, China
| | - Hao Guo
- School of Computer Science and Technology, Harbin Institute of Technology, Harbin, China.,Pengcheng Laboratory, Shenzhen, China
| | - Zhipeng Wang
- School of Mechatronics Engineering, Harbin Institute of Technology, Harbin, China
| | - Jianfei Zhu
- School of Mechatronics Engineering, Harbin Institute of Technology, Harbin, China
| | - Feng Jiang
- School of Computer Science and Technology, Harbin Institute of Technology, Harbin, China.,Pengcheng Laboratory, Shenzhen, China
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Muscle synergy differences between voluntary and reactive backward stepping. Sci Rep 2021; 11:15462. [PMID: 34326376 PMCID: PMC8322057 DOI: 10.1038/s41598-021-94699-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 07/08/2021] [Indexed: 11/08/2022] Open
Abstract
Reactive stepping responses are essential to prevent falls after a loss of balance. It has previously been well described that both voluntary and reactive step training could improve the efficacy of reactive stepping in different populations. However, the effect of aging on neuromuscular control during voluntary and reactive stepping remains unclear. Electromyography (EMG) signals during both backward voluntary stepping in response to an auditory cue and backward reactive stepping elicited by a forward slip-like treadmill perturbation during stance were recorded in ten healthy young adults and ten healthy older adults. Using muscle synergy analysis, we extracted the muscle synergies for both voluntary and reactive stepping. Our results showed that fewer muscle synergies were used during reactive stepping than during voluntary stepping in both young and older adults. Minor differences in the synergy structure were observed for both voluntary and reactive stepping between age groups. Our results indicate that there is a low similarity of muscle synergies between voluntary stepping and reactive stepping and that aging had a limited effect on the structure of muscle synergies. This study enhances our understanding of the neuromuscular basis of both voluntary and reactive stepping as well as the potential effect of aging on neuromuscular control during balance tasks.
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34
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Cano Porras D, Jacobs JV, Inzelberg R, Bahat Y, Zeilig G, Plotnik M. Patterns of whole-body muscle activations following vertical perturbations during standing and walking. J Neuroeng Rehabil 2021; 18:75. [PMID: 33957953 PMCID: PMC8101216 DOI: 10.1186/s12984-021-00836-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 02/10/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Falls commonly occur due to losses of balance associated with vertical body movements (e.g. reacting to uneven ground, street curbs). Research, however, has focused on horizontal perturbations, such as forward and backward translations of the standing surface. This study describes and compares muscle activation patterns following vertical and horizontal perturbations during standing and walking, and investigates the role of vision during standing postural responses. METHODS Fourteen healthy participants (ten males; 27±4 years-old) responded to downward, upward, forward, and backward perturbations while standing and walking in a virtual reality (VR) facility containing a moveable platform with an embedded treadmill; participants were also exposed to visual perturbations in which only the virtual scenery moved. We collected bilateral surface electromyography (EMG) signals from 8 muscles (tibialis anterior, rectus femoris, rectus abdominis, external oblique, gastrocnemius, biceps femoris, paraspinals, deltoids). Parameters included onset latency, duration of activation, and activation magnitude. Standing perturbations comprised dynamic-camera (congruent), static-camera (incongruent) and eyes-closed sensory conditions. ANOVAs were used to compare the effects of perturbation direction and sensory condition across muscles. RESULTS Vertical perturbations induced longer onset latencies and shorter durations of activation with lower activation magnitudes in comparison to horizontal perturbations (p<0.0001). Downward perturbations while standing generated earlier activation of anterior muscles to facilitate flexion (for example, p=0.0005 and p=0.0021 when comparing the early activators, rectus femoris and tibialis anterior, to a late activator, the paraspinals), whereas upward perturbations generated earlier activation of posterior muscles to facilitate extension (for example, p<0.0001 and p=0.0004, when comparing the early activators, biceps femoris and gastrocnemius, to a late activator, the rectus abdominis). Static-camera conditions induced longer onset latencies (p=0.0085 and p<0.0001 compared to eyes-closed and dynamic-camera conditions, respectively), whereas eyes-closed conditions induced longer durations of activation (p=0.0001 and p=0.0008 compared to static-camera and dynamic-camera, respectively) and larger activation magnitudes. During walking, downward perturbations promptly activated contralateral trunk and deltoid muscles (e.g., p=0.0036 for contralateral deltoid versus a late activator, the ipsilateral tibialis anterior), and upward perturbations triggered early activation of trunk flexors (e.g., p=0.0308 for contralateral rectus abdominis versus a late activator, the ipsilateral gastrocnemius). Visual perturbations elicited muscle activation in 67.7% of trials. CONCLUSION Our results demonstrate that vertical (vs. horizontal) perturbations generate unique balance-correcting muscle activations, which were consistent with counteracting vertical body extension induced by downward perturbations and vertical body flexion induced by upward perturbations. Availability of visual input appears to affect response efficiency, and incongruent visual input can adversely affect response triggering. Our findings have clinical implications for the design of robotic exoskeletons (to ensure user safety in dynamic balance environments) and for perturbation-based balance and gait rehabilitation.
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Affiliation(s)
- Desiderio Cano Porras
- Center of Advanced Technologies in Rehabilitation, Sheba Medical Center, Ramat Gan, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Perception and Action in Complex Environments, Marie Curie International Training Network, European Union's Horizons 2020 Research and Innovation Program, Brussels, Belgium.,Brightlands Institute for Smart Society-BISS, Maastricht University, Maastricht, The Netherlands
| | - Jesse V Jacobs
- Rehabilitation and Movement Science, University of Vermont, Burlington, VT, USA
| | - Rivka Inzelberg
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.,Department of Neurology and Neurosurgery, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Department of Applied Mathematics and Computer Science, The Weizmann Institute of Science, Rehovot, Israel
| | - Yotam Bahat
- Center of Advanced Technologies in Rehabilitation, Sheba Medical Center, Ramat Gan, Israel
| | - Gabriel Zeilig
- Department of Neurological Rehabilitation, Sheba Medical Center, Tel HaShomer, Ramat Gan, Israel.,Department of Physical and Rehabilitation Medicine, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Meir Plotnik
- Center of Advanced Technologies in Rehabilitation, Sheba Medical Center, Ramat Gan, Israel. .,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel. .,Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
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35
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Umehara J, Yagi M, Hirono T, Ueda Y, Ichihashi N. Quantification of muscle coordination underlying basic shoulder movements using muscle synergy extraction. J Biomech 2021; 120:110358. [PMID: 33743396 DOI: 10.1016/j.jbiomech.2021.110358] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 01/19/2021] [Accepted: 02/22/2021] [Indexed: 11/30/2022]
Abstract
Numerous muscles around the shoulder joint are required to work in a coordinated manner, even when a basic shoulder movement is executed. Muscle synergy can be utilized as an index to determine muscle coordination. The purpose of the present study was to investigate the muscle coordination among different shoulder muscles underlying basic shoulder movements based on muscle synergy. Thirteen men performed 14 multiplanar shoulder movements; five movements were associated with elevation and lowering, while five were associated with horizontal abduction and adduction. The four additional movements were simple rotations at different positions. Muscle activity was measured from 12 muscle portions using surface electromyography. Using the dimensionality reduction technique, synergies were extracted first for each movement separately ("separate" synergies), and then for the global dataset (containing all movements; "global" synergies). The least number that provided 90% of the variance accounted for was selected as the optimal number of synergies. For each subject, approximately two separate synergies and approximately six global synergies with small residual values were extracted from the separate and global electromyography datasets, respectively. Specific patterns of these muscle synergies in each task were observed during each movement. In the cross-validation method, six global synergies explained 88.0 ± 1.3% of the global dataset. These findings indicate that muscle activities underlying basic shoulder movements are expressed as six units, and these units could be proxies for shoulder muscle coordination.
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Affiliation(s)
- Jun Umehara
- Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan; Research Fellow of Japan Society for the Promotion of Science, Tokyo, Japan; Center for Information and Neural Networks, National Institute of Information and Communications Technology, Osaka, Japan.
| | - Masahide Yagi
- Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Tetsuya Hirono
- Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan; Research Fellow of Japan Society for the Promotion of Science, Tokyo, Japan
| | - Yasuyuki Ueda
- Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan; Department of Rehabilitation, Nobuhara Hospital, Hyogo, Japan
| | - Noriaki Ichihashi
- Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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Nunes PF, Ostan I, Siqueira AAG. Evaluation of Motor Primitive-Based Adaptive Control for Lower Limb Exoskeletons. Front Robot AI 2020; 7:575217. [PMID: 33501336 PMCID: PMC7805746 DOI: 10.3389/frobt.2020.575217] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 11/24/2020] [Indexed: 12/29/2022] Open
Abstract
In order to assist after-stroke individuals to rehabilitate their movements, research centers have developed lower limbs exoskeletons and control strategies for them. Robot-assisted therapy can help not only by providing support, accuracy, and precision while performing exercises, but also by being able to adapt to different patient needs, according to their impairments. As a consequence, different control strategies have been employed and evaluated, although with limited effectiveness. This work presents a bio-inspired controller, based on the concept of motor primitives. The proposed approach was evaluated on a lower limbs exoskeleton, in which the knee joint was driven by a series elastic actuator. First, to extract the motor primitives, the user torques were estimated by means of a generalized momentum-based disturbance observer combined with an extended Kalman filter. These data were provided to the control algorithm, which, at every swing phase, assisted the subject to perform the desired movement, based on the analysis of his previous step. Tests are performed in order to evaluate the controller performance for a subject walking actively, passively, and at a combination of these two conditions. Results suggest that the robot assistance is capable of compensating the motor primitive weight deficiency when the subject exerts less torque than expected. Furthermore, though only the knee joint was actuated, the motor primitive weights with respect to the hip joint were influenced by the robot torque applied at the knee. The robot also generated torque to compensate for eventual asynchronous movements of the subject, and adapted to a change in the gait characteristics within three to four steps.
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Affiliation(s)
- Polyana F. Nunes
- Rehabilitation Robotics Laboratory, Department of Mechanical Engineering, São Carlos School of Engineering, University of São Paulo, São Carlos, Brazil
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Flaxman TE, Shourijeh MS, Smale KB, Alkjær T, Simonsen EB, Krogsgaard MR, Benoit DL. Functional muscle synergies to support the knee against moment specific loads while weight bearing. J Electromyogr Kinesiol 2020; 56:102506. [PMID: 33271472 DOI: 10.1016/j.jelekin.2020.102506] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 11/11/2020] [Accepted: 11/16/2020] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVE Externally applied abduction and rotational loads are major contributors to the knee joint injury mechanism; yet, how muscles work together to stabilize the knee against these loads remains unclear. Our study sought to evaluate lower limb functional muscle synergies in healthy young adults such that muscle activation can be directly related to internal knee joint moments. METHODS Concatenated non-negative matrix factorization extracted muscle and moment synergies of 22 participants from electromyographic signals and joint moments elicited during a weight-bearing force matching protocol. RESULTS Two synergy sets were extracted: Set 1 included four synergies, each corresponding to a general anterior, posterior, medial, or lateral force direction. Frontal and transverse moments were coupled during medial and lateral force directions. Set 2 included six synergies, each corresponding to a moment type (extension/flexion, ab/adduction, internal/external rotation). Hamstrings and quadriceps dominated synergies associated with respective flexion and extension moments while quadriceps-hamstring co-activation was associated with knee abduction. Rotation moments were associated with notable contributions from hamstrings, quadriceps, gastrocnemius, and hip ab/adductors, corresponding to a general co-activation muscle synergy. CONCLUSION Our results highlight the importance of muscular co-activation of all muscles crossing the knee to support it during injury-inducing loading conditions such as externally applied knee abduction and rotation. Functional muscle synergies can provide new insight into the relationship between neuromuscular control and knee joint stability by directly associating biomechanical variables to muscle activation.
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Affiliation(s)
- Teresa E Flaxman
- School of Rehabilitation Sciences, University of Ottawa, 451 Smyth Rd, Ottawa, ON K1H 8M5, Canada
| | - Mohammad S Shourijeh
- Department of Mechanical Engineering, Rice University, 6100 Main St, Houston, TX 77005, USA
| | - Kenneth B Smale
- School of Human Kinetics, University of Ottawa, 125 University Pr, Ottawa, ON K1N 1A2, Canada
| | - Tine Alkjær
- Department of Biomedical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Erik B Simonsen
- Department of Neuroscience, University of Copenhagen, Blegdamsvej 3B, DK-2200 Copenhagen N, Denmark
| | - Michael R Krogsgaard
- Section for Sportstraumatology, Bispebjerg Hospital, Bispebjerg Bakke 23, DK-2400 Copenhagen, NV, Denmark
| | - Daniel L Benoit
- School of Rehabilitation Sciences, University of Ottawa, 451 Smyth Rd, Ottawa, ON K1H 8M5, Canada; School of Human Kinetics, University of Ottawa, 125 University Pr, Ottawa, ON K1N 1A2, Canada.
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Solis-Escalante T, De Kam D, Weerdesteyn V. Classification of Rhythmic Cortical Activity Elicited by Whole-Body Balance Perturbations Suggests the Cortical Representation of Direction-Specific Changes in Postural Stability. IEEE Trans Neural Syst Rehabil Eng 2020; 28:2566-2574. [PMID: 33021931 DOI: 10.1109/tnsre.2020.3028966] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Postural responses that effectively recover balance following unexpected postural changes need to be tailored to the characteristics of the postural change. We hypothesized that cortical dynamics involved in top-down regulation of postural responses carry information about directional postural changes (i.e., sway) imposed by sudden perturbations to standing balance (i.e., support surface translations). To test our hypothesis, we evaluated the single-trial classification of perturbation-induced directional changes in postural stability from high-density EEG. We analyzed EEG recordings from six young able-bodied individuals and three older individuals with chronic hemiparetic stroke, which were acquired while individuals reacted to low-intensity balance perturbations. Using common spatial patterns for feature extraction and linear discriminant analysis or support vector machines for classification, we achieved classification accuracies above random level (p < 0.05; cross-validated) for the classification of four different sway directions (one vs. the rest scheme). Screening of spectral features (3-50 Hz) revealed that the highest classification performance occurred when low-frequency (3-10 Hz) spectral features were used. Strikingly, the participant-specific classification results were qualitatively similar between young able-bodied individuals and older individuals with chronic hemiparetic stroke. Our findings demonstrate that low-frequency spectral components, corresponding to the cortical theta rhythm, carry direction-specific information about changes in postural stability. Our work presents a new perspective on the cortical representation of postural stability and the possible role of the theta rhythm in the modulation of (directional) reactive balance responses. Importantly, our work provides preliminary evidence that the cortical encoding of direction-specific changes in postural stability is present in chronic hemiparetic stroke.
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Changes in the range of angular variation of the ankle, knee, hip and neck joints related to the awareness of an impending perturbation. J Bodyw Mov Ther 2020; 24:24-28. [DOI: 10.1016/j.jbmt.2020.07.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 07/06/2020] [Accepted: 07/27/2020] [Indexed: 11/20/2022]
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Solis-Escalante T, Stokkermans M, Cohen MX, Weerdesteyn V. Cortical responses to whole-body balance perturbations index perturbation magnitude and predict reactive stepping behavior. Eur J Neurosci 2020; 54:8120-8138. [PMID: 32931066 PMCID: PMC9290492 DOI: 10.1111/ejn.14972] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 09/04/2020] [Accepted: 09/05/2020] [Indexed: 11/30/2022]
Abstract
The goal of this study was to determine whether the cortical responses elicited by whole‐body balance perturbations were similar to established cortical markers of action monitoring. Postural changes imposed by balance perturbations elicit a robust negative potential (N1) and a brisk increase of theta activity in the electroencephalogram recorded over midfrontal scalp areas. Because action monitoring is a cognitive function proposed to detect errors and initiate corrective adjustments, we hypothesized that the possible cortical markers of action monitoring during balance control (N1 potential and theta rhythm) scale with perturbation intensity and the eventual execution of reactive stepping responses (as opposed to feet‐in‐place responses). We recorded high‐density electroencephalogram from eleven young individuals, who participated in an experimental balance assessment. The participants were asked to recover balance following anteroposterior translations of the support surface at various intensities, while attempting to maintain both feet in place. We estimated source‐resolved cortical activity using independent component analysis. Combining time‐frequency decomposition and group‐level general linear modeling of single‐trial responses, we found a significant relation of the interaction between perturbation intensity and stepping responses with multiple cortical features from the midfrontal cortex, including the N1 potential, and theta, alpha, and beta rhythms. Our findings suggest that the cortical responses to balance perturbations index the magnitude of a deviation from a stable postural state to predict the need for reactive stepping responses. We propose that the cortical control of balance may involve cognitive control mechanisms (i.e., action monitoring) that facilitate postural adjustments to maintain postural stability.
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Affiliation(s)
- Teodoro Solis-Escalante
- Department of Rehabilitation, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Mitchel Stokkermans
- Department of Rehabilitation, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Neuroinformatics, Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, The Netherlands
| | - Michael X Cohen
- Department of Neuroinformatics, Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, The Netherlands
| | - Vivian Weerdesteyn
- Department of Rehabilitation, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands.,Sint Maartenskliniek Research, Nijmegen, The Netherlands
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41
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Payne AM, Sawers A, Allen JL, Stapley PJ, Macpherson JM, Ting LH. Reorganization of motor modules for standing reactive balance recovery following pyridoxine-induced large-fiber peripheral sensory neuropathy in cats. J Neurophysiol 2020; 124:868-882. [PMID: 32783597 DOI: 10.1152/jn.00739.2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Task-level goals such as maintaining standing balance are achieved through coordinated muscle activity. Consistent and individualized groupings of synchronously activated muscles can be estimated from muscle recordings in terms of motor modules or muscle synergies, independent of their temporal activation. The structure of motor modules can change with motor training, neurological disorders, and rehabilitation, but the central and peripheral mechanisms underlying motor module structure remain unclear. To assess the role of peripheral somatosensory input on motor module structure, we evaluated changes in the structure of motor modules for reactive balance recovery following pyridoxine-induced large-fiber peripheral somatosensory neuropathy in previously collected data in four adult cats. Somatosensory fiber loss, quantified by postmortem histology, varied from mild to severe across cats. Reactive balance recovery was assessed using multidirectional translational support-surface perturbations over days to weeks throughout initial impairment and subsequent recovery of balance ability. Motor modules within each cat were quantified by non-negative matrix factorization and compared in structure over time. All cats exhibited changes in the structure of motor modules for reactive balance recovery after somatosensory loss, providing evidence that somatosensory inputs influence motor module structure. The impact of the somatosensory disturbance on the structure of motor modules in well-trained adult cats indicates that somatosensory mechanisms contribute to motor module structure, and therefore may contribute to some of the pathological changes in motor module structure in neurological disorders. These results further suggest that somatosensory nerves could be targeted during rehabilitation to influence pathological motor modules for rehabilitation.NEW & NOTEWORTHY Stable motor modules for reactive balance recovery in well-trained adult cats were disrupted following pyridoxine-induced peripheral somatosensory neuropathy, suggesting somatosensory inputs contribute to motor module structure. Furthermore, the motor module structure continued to change as the animals regained the ability to maintain standing balance, but the modules generally did not recover pre-pyridoxine patterns. These results suggest changes in somatosensory input and subsequent learning may contribute to changes in motor module structure in pathological conditions.
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Affiliation(s)
- Aiden M Payne
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Tech and Emory University, Atlanta, Georgia
| | - Andrew Sawers
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, Illinois
| | - Jessica L Allen
- Department of Chemical and Biomedical Engineering, West Virginia University, Morgantown, West Virginia
| | - Paul J Stapley
- Neurological Sciences Institute, Oregon Health and Science University, Beaverton, Oregon
| | - Jane M Macpherson
- Neurological Sciences Institute, Oregon Health and Science University, Beaverton, Oregon
| | - Lena H Ting
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Tech and Emory University, Atlanta, Georgia.,Department of Rehabilitation Medicine, Division of Physical Therapy, Emory University, Atlanta, Georgia
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da Silva Costa AA, Moraes R, Hortobágyi T, Sawers A. Older adults reduce the complexity and efficiency of neuromuscular control to preserve walking balance. Exp Gerontol 2020; 140:111050. [PMID: 32750424 DOI: 10.1016/j.exger.2020.111050] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 07/24/2020] [Accepted: 07/28/2020] [Indexed: 02/07/2023]
Abstract
Healthy aging modifies neuromuscular control of dynamic balance. Challenging tasks could amplify such modifications, providing clinical insights. We examined the effects of age and walking condition difficulty on neuromuscular control of walking balance. We analyzed whole-body kinematics and activity of 13 right leg and trunk muscles in 17 young (11 males and 6 females; age 24 ± 3 years) and 14 older adults (3 males and 11 females; age 69 ± 4 years) while walking on a taped line on the floor and a 6-cm wide beam. Spatiotemporal parameters of gait, margin of stability, motor performance, and muscle synergies were estimated. Regardless of age, maintaining walking balance was more difficult on the beam compared to the taped line as evidenced by a shorter distance walked (17.3%), a reduction in step length (5.8%) and speed (10.3%), as well as a 40.0% smaller margin of stability during beam vs. tape walking. The number of muscle synergies was also higher during beam vs. tape walking. Compared to younger adults, older adults had larger margin of stability during beam walking. Older adults also had higher muscle co-activity within each muscle synergy and greater variance accounted for by the first muscle synergy regardless of condition. Such age-effects may be interpreted as a safer, less efficient, and less complex neuromuscular modular control strategy. In conclusion, beam walking increased the difficulty of maintaining walking balance and induced adaptations in modular control. It seems that healthy older adults reduce the complexity and efficiency of neuromuscular control of walking to preserve walking balance.
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Affiliation(s)
- Andréia Abud da Silva Costa
- Ribeirão Preto Medical School, Graduate Program in Rehabilitation and Functional Performance, University of São Paulo, Brazil; Biomechanics and Motor Control Lab, School of Physical Education and Sport of Ribeirão Preto, University of São Paulo, Brazil
| | - Renato Moraes
- Ribeirão Preto Medical School, Graduate Program in Rehabilitation and Functional Performance, University of São Paulo, Brazil; Biomechanics and Motor Control Lab, School of Physical Education and Sport of Ribeirão Preto, University of São Paulo, Brazil
| | - Tibor Hortobágyi
- Center for Human Movement Sciences, University of Groningen Medical Center, Groningen, the Netherlands
| | - Andrew Sawers
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL, United States.
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Al Borno M, Hicks JL, Delp SL. The effects of motor modularity on performance, learning and generalizability in upper-extremity reaching: a computational analysis. J R Soc Interface 2020; 17:20200011. [PMID: 32486950 PMCID: PMC7328389 DOI: 10.1098/rsif.2020.0011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 05/06/2020] [Indexed: 11/12/2022] Open
Abstract
It has been hypothesized that the central nervous system simplifies the production of movement by limiting motor commands to a small set of modules known as muscle synergies. Recently, investigators have questioned whether a low-dimensional controller can produce the rich and flexible behaviours seen in everyday movements. To study this issue, we implemented muscle synergies in a biomechanically realistic model of the human upper extremity and performed computational experiments to determine whether synergies introduced task performance deficits, facilitated the learning of movements, and generalized to different movements. We derived sets of synergies from the muscle excitations our dynamic optimizations computed for a nominal task (reaching in a plane). Then we compared the performance and learning rates of a controller that activated all muscles independently to controllers that activated the synergies derived from the nominal reaching task. We found that a controller based on synergies had errors within 1 cm of a full-dimensional controller and achieved faster learning rates (as estimated from computational time to converge). The synergy-based controllers could also accomplish new tasks-such as reaching to targets on a higher or lower plane, and starting from alternative initial poses-with average errors similar to a full-dimensional controller.
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Affiliation(s)
- Mazen Al Borno
- Department of Bioengineering and Mechanical Engineering, Stanford University, Stanford, CA, USA
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44
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Singh RE, White G, Delis I, Iqbal K. Alteration of muscle synergy structure while walking under increased postural constraints. COGNITIVE COMPUTATION AND SYSTEMS 2020. [DOI: 10.1049/ccs.2019.0021] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Affiliation(s)
- Rajat Emanuel Singh
- Department of Systems EngineeringUniversity of Arkansas at Little RockARUSA
- School of Counseling Human Performance & RehabilitationUniversity of Arkansas at Little RockARUSA
| | - Gannon White
- Department of KinesiologyColorado Mesa UniversityCOUSA
| | | | - Kamran Iqbal
- Department of Systems EngineeringUniversity of Arkansas at Little RockARUSA
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45
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Abstract
The growing interest in wearable robots opens the challenge for developing intuitive and natural control strategies. Among several human–machine interaction approaches, myoelectric control consists of decoding the motor intention from muscular activity (or EMG signals) with the aim of driving prosthetic or assistive robotic devices accordingly, thus establishing an intimate human–machine connection. In this scenario, bio-inspired approaches, e.g., synergy-based controllers, are revealed to be the most robust. However, synergy-based myo-controllers already proposed in the literature consider muscle patterns that are computed considering only the total variance reconstruction rate of the EMG signals, without taking into account the performance of the controller in the task (or application) space. In this work, extending a previous study, the authors presented an autoencoder-based neural model able to extract muscles synergies for motion intention detection while optimizing the task performance in terms of force/moment reconstruction. The proposed neural topology has been validated with EMG signals acquired from the main upper limb muscles during planar isometric reaching tasks performed in a virtual environment while wearing an exoskeleton. The presented model has been compared with the non-negative matrix factorization algorithm (i.e., the most used approach in the literature) in terms of muscle synergy extraction quality, and with three techniques already presented in the literature in terms of goodness of shoulder and elbow predicted moments. The results of the experimental comparisons have showed that the proposed model outperforms the state-of-art synergy-based joint moment estimators at the expense of the quality of the EMG signals reconstruction. These findings demonstrate that a trade-off, between the capability of the extracted muscle synergies to better describe the EMG signals variability and the task performance in terms of force reconstruction, can be achieved. The results of this study might open new horizons on synergies extraction methodologies, optimized synergy-based myo-controllers and, perhaps, reveals useful hints about their origin.
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Schumacher C, Sharbafi M, Seyfarth A, Rode C. Biarticular muscles in light of template models, experiments and robotics: a review. J R Soc Interface 2020; 17:20180413. [PMID: 32093540 PMCID: PMC7061696 DOI: 10.1098/rsif.2018.0413] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 01/31/2020] [Indexed: 11/25/2022] Open
Abstract
Leg morphology is an important outcome of evolution. A remarkable morphological leg feature is the existence of biarticular muscles that span adjacent joints. Diverse studies from different fields of research suggest a less coherent understanding of the muscles' functionality in cyclic, sagittal plane locomotion. We structured this review of biarticular muscle function by reflecting biomechanical template models, human experiments and robotic system designs. Within these approaches, we surveyed the contribution of biarticular muscles to the locomotor subfunctions (stance, balance and swing). While mono- and biarticular muscles do not show physiological differences, the reviewed studies provide evidence for complementary and locomotor subfunction-specific contributions of mono- and biarticular muscles. In stance, biarticular muscles coordinate joint movements, improve economy (e.g. by transferring energy) and secure the zig-zag configuration of the leg against joint overextension. These commonly known functions are extended by an explicit role of biarticular muscles in controlling the angular momentum for balance and swing. Human-like leg arrangement and intrinsic (compliant) properties of biarticular structures improve the controllability and energy efficiency of legged robots and assistive devices. Future interdisciplinary research on biarticular muscles should address their role for sensing and control as well as non-cyclic and/or non-sagittal motions, and non-static moment arms.
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Affiliation(s)
- C. Schumacher
- Lauflabor Locomotion Laboratory, Centre for Cognitive Science, Institute of Sport Science, Technische Universität Darmstadt, Darmstadt, Germany
| | - M. Sharbafi
- Lauflabor Locomotion Laboratory, Centre for Cognitive Science, Institute of Sport Science, Technische Universität Darmstadt, Darmstadt, Germany
| | - A. Seyfarth
- Lauflabor Locomotion Laboratory, Centre for Cognitive Science, Institute of Sport Science, Technische Universität Darmstadt, Darmstadt, Germany
| | - C. Rode
- Motion and Exercise Science, University of Stuttgart, Stuttgart, Germany
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Dwivedi SK, Ngeo J, Shibata T. Extraction of Nonlinear Synergies for Proportional and Simultaneous Estimation of Finger Kinematics. IEEE Trans Biomed Eng 2020; 67:2646-2658. [PMID: 31976877 DOI: 10.1109/tbme.2020.2967154] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE Proportional and simultaneous est-imation of finger kinematics from surface EMG based on the assumption that there exists a correlation between muscle activations and finger kinematics in low dimensional space. METHODS We employ Manifold Relevance Determination (MRD), a multi-view learning model with a nonparametric Bayesian approach, to extract the nonlinear muscle and kinematics synergies and the relationship between them by studying muscle activations (input-space) together with the finger kinematics (output-space). RESULTS This study finds that there exist muscle synergies which are associated with kinematic synergies. The acquired nonlinear synergies and the association between them has further been utilized for the estimation of finger kinematics from muscle activation inputs, and the proposed approach has outperformed other commonly used linear and nonlinear regression approaches with an average correlation coefficient of 0.91±0.03. CONCLUSION There exists an association between muscle and kinematic synergies which can be used for the proportional and simultaneous estimation of finger kinematics from the muscle activation inputs. SIGNIFICANCE The findings of this study not only presents a viable approach for accurate and intuitive myoelectric control but also provides a new perspective on the muscle synergies in the motor control community.
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48
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Neuromechanical adjustments when walking with an aiding or hindering horizontal force. Eur J Appl Physiol 2019; 120:91-106. [DOI: 10.1007/s00421-019-04251-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 10/28/2019] [Indexed: 02/02/2023]
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49
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Holubarsch J, Helm M, Ringhof S, Gollhofer A, Freyler K, Ritzmann R. Stumbling reactions in hypo and hyper gravity - muscle synergies are robust across different perturbations of human stance during parabolic flights. Sci Rep 2019; 9:10490. [PMID: 31324854 PMCID: PMC6642199 DOI: 10.1038/s41598-019-47091-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Accepted: 07/10/2019] [Indexed: 11/21/2022] Open
Abstract
The control of bipedal stance and the capacity to regain postural equilibrium after its deterioration in variable gravities are crucial prerequisites for manned space missions. With an emphasize on natural orthograde posture, computational techniques synthesize muscle activation patterns of high complexity to a simple synergy organization. We used nonnegative matrix factorization to identify muscle synergies during postural recovery responses in human and to examine the functional significance of such synergies for hyper-gravity (1.75 g) and hypo-gravity (0.25 g). Electromyographic data were recorded from leg, trunk and arm muscles of five human exposed to five modes of anterior and posterior support surface translations during parabolic flights including transitional g-levels of 0.25, 1 and 1.75 g. Results showed that in 1 g four synergies accounted for 99% of the automatic postural response across all muscles and perturbation directions. Each synergy in 1 g was correlated to the corresponding one in 0.25 and 1.75 g. This study therefore emphasizes the similarity of the synergy organization of postural recovery responses in Earth, hypo- and hyper-gravity conditions, indicating that the muscle synergies and segmental strategies acquired under terrestrial habits are robust and persistent across variable and acute changes in gravity levels.
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Affiliation(s)
- Janek Holubarsch
- Department of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Michael Helm
- Department of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Steffen Ringhof
- Department of Sport and Sport Science, University of Freiburg, Freiburg, Germany.
| | - Albert Gollhofer
- Department of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Kathrin Freyler
- Department of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Ramona Ritzmann
- Department of Sport and Sport Science, University of Freiburg, Freiburg, Germany.,Praxisklinik Rennbahn AG, Muttenz, Switzerland
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50
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Dewolf AH, Ivanenko YP, Zelik KE, Lacquaniti F, Willems PA. Differential activation of lumbar and sacral motor pools during walking at different speeds and slopes. J Neurophysiol 2019; 122:872-887. [PMID: 31291150 DOI: 10.1152/jn.00167.2019] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Organization of spinal motor output has become of interest for investigating differential activation of lumbar and sacral motor pools during locomotor tasks. Motor pools are associated with functional grouping of motoneurons of the lower limb muscles. Here we examined how the spatiotemporal organization of lumbar and sacral motor pool activity during walking is orchestrated with slope of terrain and speed of progression. Ten subjects walked on an instrumented treadmill at different slopes and imposed speeds. Kinetics, kinematics, and electromyography of 16 lower limb muscles were recorded. The spinal locomotor output was assessed by decomposing the coordinated muscle activation profiles into a small set of common factors and by mapping them onto the rostrocaudal location of the motoneuron pools. Our results show that lumbar and sacral motor pool activity depend on slope and speed. Compared with level walking, sacral motor pools decrease their activity at negative slopes and increase at positive slopes, whereas lumbar motor pools increase their engagement when both positive and negative slope increase. These findings are consistent with a differential involvement of the lumbar and the sacral motor pools in relation to changes in positive and negative center of body mass mechanical power production due to slope and speed.NEW & NOTEWORTHY In this study, the spatiotemporal maps of motoneuron activity in the spinal cord were assessed during walking at different slopes and speeds. We found differential involvement of lumbar and sacral motor pools in relation to changes in positive and negative center of body mass power production due to slope and speed. The results are consistent with recent findings about the specialization of neuronal networks located at different segments of the spinal cord for performing specific locomotor tasks.
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Affiliation(s)
- A H Dewolf
- Laboratory of Biomechanics and Physiology of Locomotion, Institute of NeuroScience, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Y P Ivanenko
- Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Rome, Italy
| | - K E Zelik
- Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Rome, Italy.,Department of Mechanical Engineering, Vanderbilt University, Nashville, Tennessee.,Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee.,Department of Physical Medicine and Rehabilitation, Vanderbilt University, Nashville, Tennessee
| | - F Lacquaniti
- Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Rome, Italy.,Department of Systems Medicine and Center of Space Biomedicine, University of Rome Tor Vergata, Rome, Italy
| | - P A Willems
- Laboratory of Biomechanics and Physiology of Locomotion, Institute of NeuroScience, Université catholique de Louvain, Louvain-la-Neuve, Belgium
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