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Aoyama T, Ae K, Taguchi T, Kawamori Y, Sasaki D, Kawamura T, Kohno Y. Spatiotemporal patterns of throwing muscle synergies in yips-affected baseball players. Sci Rep 2024; 14:2649. [PMID: 38302478 PMCID: PMC10834996 DOI: 10.1038/s41598-024-52332-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 01/17/2024] [Indexed: 02/03/2024] Open
Abstract
"Yips" are involuntary movements that interfere with the automatic execution of sports movements. However, how the coordination among the various muscles necessary for sports movements is impaired in athletes with yips remains to be fully understood. This study aimed to assess whether muscle synergy analysis through non-negative matrix factorization (NMF) could identify impaired spatiotemporal muscle coordination in baseball players with throwing yips. Twenty-two college baseball players, including 12 with and 10 without yips symptoms participated in the study. Electromyographic activity was recorded from 13 ipsilateral upper extremity muscles during full-effort throwing. Muscle synergies were extracted through NMF. Cluster analysis was conducted to identify any common spatiotemporal patterns of muscle synergies in players with yips. Whether individual players with yips showed deviations in spatiotemporal patterns of muscle synergies compared with control players was also investigated. Four muscle synergies were extracted for each player, but none were specific to the yips group. However, a more detailed analysis of individual players revealed that two of the three players who presented dystonic symptoms during the experiment exhibited specific patterns that differed from those in control players. By contrast, each player whose symptoms were not reproduced during the experiment presented spatiotemporal patterns of muscle synergies similar to those of the control group. The results of this study indicate no common spatiotemporal pattern of muscle synergies specific to the yips group. Furthermore, these results suggest that the spatiotemporal pattern of muscle synergies in baseball throwing motion is not impaired in situations where symptoms are not reproduced even if the players have yips symptoms. However, muscle synergy analysis can identify the characteristics of muscle coordination of players who exhibit dystonic movements. These findings can be useful in developing personalized therapeutic strategies based on individual characteristics of yips symptoms.
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Affiliation(s)
- Toshiyuki Aoyama
- Department of Physical Therapy, Ibaraki Prefectural University of Health Sciences, 4669-2 Ami, Ami-Machi, Inashiki-gun, Ibaraki, Japan.
| | - Kazumichi Ae
- Faculty of Sport Science, Nippon Sport Science University, Tokyo, Japan
| | - Takahiro Taguchi
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan
| | - Yuna Kawamori
- Department of Physical Therapy, Ibaraki Prefectural University of Health Sciences, 4669-2 Ami, Ami-Machi, Inashiki-gun, Ibaraki, Japan
| | - Daisuke Sasaki
- Department of Physical Therapy, Ibaraki Prefectural University of Health Sciences, 4669-2 Ami, Ami-Machi, Inashiki-gun, Ibaraki, Japan
| | - Takashi Kawamura
- Institute of Health and Sport Sciences, University of Tsukuba, Tsukuba, Japan
| | - Yutaka Kohno
- Centre for Medical Sciences, Ibaraki Prefectural University of Health Sciences, Ami, Japan
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Spomer AM, Yan RZ, Schwartz MH, Steele KM. Motor control complexity can be dynamically simplified during gait pattern exploration using motor control-based biofeedback. J Neurophysiol 2023; 129:984-998. [PMID: 37017327 PMCID: PMC10125030 DOI: 10.1152/jn.00323.2022] [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: 07/31/2022] [Revised: 03/28/2023] [Accepted: 03/29/2023] [Indexed: 04/06/2023] Open
Abstract
Understanding how the central nervous system coordinates diverse motor outputs has been a topic of extensive investigation. Although it is generally accepted that a small set of synergies underlies many common activities, such as walking, whether synergies are equally robust across a broader array of gait patterns or can be flexibly modified remains unclear. Here, we evaluated the extent to which synergies changed as nondisabled adults (n = 14) explored gait patterns using custom biofeedback. Secondarily, we used Bayesian additive regression trees to identify factors that were associated with synergy modulation. Participants explored 41.1 ± 8.0 gait patterns using biofeedback, during which synergy recruitment changed depending on the type and magnitude of gait pattern modification. Specifically, a consistent set of synergies was recruited to accommodate small deviations from baseline, but additional synergies emerged for larger gait changes. Synergy complexity was similarly modulated; complexity decreased for 82.6% of the attempted gait patterns, but distal gait mechanics were strongly associated with these changes. In particular, greater ankle dorsiflexion moments and knee flexion through stance, as well as greater knee extension moments at initial contact, corresponded to a reduction in synergy complexity. Taken together, these results suggest that the central nervous system preferentially adopts a low-dimensional, largely invariant control strategy but can modify that strategy to produce diverse gait patterns. Beyond improving understanding of how synergies are recruited during gait, study outcomes may also help identify parameters that can be targeted with interventions to alter synergies and improve motor control after neurological injury.NEW & NOTEWORTHY We used a motor control-based biofeedback system and machine learning to characterize the extent to which nondisabled adults can modulate synergies during gait pattern exploration. Results revealed that a small library of synergies underlies an array of gait patterns but that recruitment from this library changes as a function of the imposed biomechanical constraints. Our findings enhance understanding of the neural control of gait and may inform biofeedback strategies to improve synergy recruitment after neurological injury.
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Affiliation(s)
- Alyssa M Spomer
- Department of Mechanical Engineering, University of Washington, Seattle, Washington, United States
| | - Robin Z Yan
- Department of Mechanical Engineering, University of Washington, Seattle, Washington, United States
| | - Michael H Schwartz
- James R. Gage Center for Gait & Motion Analysis, Gillette Children's Specialty Healthcare, Saint Paul, Minnesota, United States
- Department of Orthopedic Surgery, University of Minnesota, Minneapolis, Minnesota, United States
| | - Katherine M Steele
- Department of Mechanical Engineering, University of Washington, Seattle, Washington, United States
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Kettlety SA, Finley JM, Reisman DS, Schweighofer N, Leech KA. Speed-dependent biomechanical changes vary across individual gait metrics post-stroke relative to neurotypical adults. J Neuroeng Rehabil 2023; 20:14. [PMID: 36703214 PMCID: PMC9881336 DOI: 10.1186/s12984-023-01139-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 01/17/2023] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Gait training at fast speeds is recommended to reduce walking activity limitations post-stroke. Fast walking may also reduce gait kinematic impairments post-stroke. However, it is unknown if differences in gait kinematics between people post-stroke and neurotypical adults decrease when walking at faster speeds. OBJECTIVE To determine the effect of faster walking speeds on gait kinematics post-stroke relative to neurotypical adults walking at similar speeds. METHODS We performed a secondary analysis with data from 28 people post-stroke and 50 neurotypical adults treadmill walking at multiple speeds. We evaluated the effects of speed and group on individual spatiotemporal and kinematic metrics and performed k-means clustering with all metrics at self-selected and fast speeds. RESULTS People post-stroke decreased step length asymmetry and trailing limb angle impairment, reducing between-group differences at fast speeds. Speed-dependent changes in peak swing knee flexion, hip hiking, and temporal asymmetries exaggerated between-group differences. Our clustering analyses revealed two clusters. One represented neurotypical gait behavior, composed of neurotypical and post-stroke participants. The other characterized stroke gait behavior-comprised entirely of participants post-stroke with smaller lower extremity Fugl-Meyer scores than the post-stroke participants in the neurotypical gait behavior cluster. Cluster composition was largely consistent at both speeds, and the distance between clusters increased at fast speeds. CONCLUSIONS The biomechanical effect of fast walking post-stroke varied across individual gait metrics. For participants within the stroke gait behavior cluster, walking faster led to an overall gait pattern more different than neurotypical adults compared to the self-selected speed. This suggests that to potentiate the biomechanical benefits of walking at faster speeds and improve the overall gait pattern post-stroke, gait metrics with smaller speed-dependent changes may need to be specifically targeted within the context of fast walking.
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Affiliation(s)
- Sarah A Kettlety
- Division of Biokinesiology and Physical Therapy, University of Southern California, 1540 E Alcazar St, CHP 155, Los Angeles, CA, 90033, USA
| | - James M Finley
- Division of Biokinesiology and Physical Therapy, University of Southern California, 1540 E Alcazar St, CHP 155, Los Angeles, CA, 90033, USA
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, USA
| | - Darcy S Reisman
- Department of Physical Therapy, University of Delaware, 540 S College Ave, Suite 160, Newark, DE, 19713, USA
- Biomechanics and Movement Science Program, University of Delaware, Newark, DE, USA
| | - Nicolas Schweighofer
- Division of Biokinesiology and Physical Therapy, University of Southern California, 1540 E Alcazar St, CHP 155, Los Angeles, CA, 90033, USA
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, USA
| | - Kristan A Leech
- Division of Biokinesiology and Physical Therapy, University of Southern California, 1540 E Alcazar St, CHP 155, Los Angeles, CA, 90033, USA.
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Sun SY, Giszter SF, Harkema SJ, Angeli CA. Modular organization of locomotor networks in people with severe spinal cord injury. Front Neurosci 2022; 16:1041015. [PMID: 36570830 PMCID: PMC9768556 DOI: 10.3389/fnins.2022.1041015] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Accepted: 11/16/2022] [Indexed: 12/12/2022] Open
Abstract
Introduction Previous studies support modular organization of locomotor circuitry contributing to the activation of muscles in a spatially and temporally organized manner during locomotion. Human spinal circuitry may reorganize after spinal cord injury; however, it is unclear if reorganization of spinal circuitry post-injury affects the modular organization. Here we characterize the modular synergy organization of locomotor muscle activity expressed during assisted stepping in subjects with complete and incomplete spinal cord injury (SCI) of varying chronicity, before any explicit training regimen. We also investigated whether the synergy characteristics changed in two subjects who achieved independent walking after training with spinal cord epidural stimulation. Methods To capture synergy structures during stepping, individuals with SCI were stepped on a body-weight supported treadmill with manual facilitation, while electromyography (EMGs) were recorded from bilateral leg muscles. EMGs were analyzed using non-negative matrix factorization (NMF) and independent component analysis (ICA) to identify synergy patterns. Synergy patterns from the SCI subjects were compared across different clinical characteristics and to non-disabled subjects (NDs). Results Results for both NMF and ICA indicated that the subjects with SCI were similar among themselves, but expressed a greater variability in the number of synergies for criterion variance capture compared to NDs, and weaker correlation to NDs. ICA yielded a greater number of muscle synergies than NMF. Further, the clinical characteristics of SCI subjects and chronicity did not predict any significant differences in the spatial synergy structures despite any neuroplastic changes. Further, post-training synergies did not become closer to ND synergies in two individuals. Discussion These findings suggest fundamental differences between motor modules expressed in SCIs and NDs, as well as a striking level of spatial and temporal synergy stability in motor modules in the SCI population, absent the application of specific interventions.
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Affiliation(s)
- Soo Yeon Sun
- Department of Physical Therapy, Alvernia University, Reading, PA, United States
| | - Simon F. Giszter
- Department of Neurobiology and Anatomy, College of Medicine, Drexel University, Philadelphia, PA, United States,School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, United States
| | - Susan J. Harkema
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY, United States,Department of Neurological Surgery, University of Louisville, Louisville, KY, United States,Frazier Rehab Institute, University of Louisville Health, Louisville, KY, United States
| | - Claudia A. Angeli
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY, United States,Frazier Rehab Institute, University of Louisville Health, Louisville, KY, United States,Department of Bioengineering, University of Louisville, Louisville, KY, United States,*Correspondence: Claudia A. Angeli,
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Aoyama T, Ae K, Kohno Y. Interindividual differences in upper limb muscle synergies during baseball throwing motion in male college baseball players. J Biomech 2022; 145:111384. [PMID: 36403527 DOI: 10.1016/j.jbiomech.2022.111384] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 09/21/2022] [Accepted: 11/09/2022] [Indexed: 11/15/2022]
Abstract
Throwing is a fundamental human motor behavior that has evolved to aid hunting and defense against predators. In modern humans, accurate throwing is an important skill required in many sports. However, the spatiotemporal coordination of muscles during baseball throwing has not been fully elucidated. We herein aimed to identify the muscle synergies involved in baseball throwing and determine whether their spatiotemporal patterns are shared among individuals. Ten college baseball players participated in this study. Electromyographic activity was recorded from 13 ipsilateral upper limb muscles during throwing using full effort. Non-negative matrix factorization was used to extract the motor module composition and temporal activation patterns during baseball throwing, followed by k-means analysis to cluster the extracted motor modules based on their similarity. Four motor modules were extracted for each player. These were classified into four clusters (Clusters 1-4), each reaching the peak activity sequentially from the early cocking phase to ball release. Spatiotemporal interindividual similarity in the muscle synergy cluster comprising the muscles activated during the transition from early cocking to late cocking (Cluster 2) was significantly lower than that in the other clusters. There was no individual-specific muscle synergy. These results suggest that the skilled baseball throwing motion acquired through years of practice may consist of four basic muscle synergies that are common among individuals with some differences in their spatiotemporal patterns.
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Affiliation(s)
- Toshiyuki Aoyama
- Department of Physical Therapy, Ibaraki Prefectural University of Health Sciences, 4669-2 Ami, Ami-Machi, Inashiki-gun, Ibaraki, Japan.
| | - Kazumichi Ae
- Nippon Sport Science University, 7-1-1 Fukasawa, Setagaya-ward, Tokyo, Japan
| | - Yutaka Kohno
- Centre for Medical Sciences, Ibaraki Prefectural University of Health Sciences, 4669-2 Ami, Ami-Machi, Inashiki-gun, Ibaraki, Japan
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Srivastava S, Seamon BA, Marebwa BK, Wilmskoetter J, Bowden MG, Gregory CM, Seo NJ, Hanlon CA, Bonilha L, Brown TR, Neptune RR, Kautz SA. The relationship between motor pathway damage and flexion-extension patterns of muscle co-excitation during walking. Front Neurol 2022; 13:968385. [PMID: 36388195 PMCID: PMC9650203 DOI: 10.3389/fneur.2022.968385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 10/12/2022] [Indexed: 01/16/2023] Open
Abstract
Background Mass flexion-extension co-excitation patterns during walking are often seen as a consequence of stroke, but there is limited understanding of the specific contributions of different descending motor pathways toward their control. The corticospinal tract is a major descending motor pathway influencing the production of normal sequential muscle coactivation patterns for skilled movements. However, control of walking is also influenced by non-corticospinal pathways such as the corticoreticulospinal pathway that possibly contribute toward mass flexion-extension co-excitation patterns during walking. The current study sought to investigate the associations between damage to corticospinal (CST) and corticoreticular (CRP) motor pathways following stroke and the presence of mass flexion-extension patterns during walking as evaluated using module analysis. Methods Seventeen healthy controls and 44 stroke survivors were included in the study. We used non-negative matrix factorization for module analysis of paretic leg electromyographic activity. We typically have observed four modules during walking in healthy individuals. Stroke survivors often have less independently timed modules, for example two-modules presented as mass flexion-extension pattern. We used diffusion tensor imaging-based analysis where streamlines connecting regions of interest between the cortex and brainstem were computed to evaluate CST and CRP integrity. We also used a coarse classification tree analysis to evaluate the relative CST and CRP contribution toward module control. Results Interhemispheric CST asymmetry was associated with worse lower extremity Fugl-Meyer score (p = 0.023), propulsion symmetry (p = 0.016), and fewer modules (p = 0.028). Interhemispheric CRP asymmetry was associated with worse lower extremity Fugl-Meyer score (p = 0.009), Dynamic gait index (p = 0.035), Six-minute walk test (p = 0.020), Berg balance scale (p = 0.048), self-selected walking speed (p = 0.041), and propulsion symmetry (p = 0.001). The classification tree model reveled that substantial ipsilesional CRP or CST damage leads to a two-module pattern and poor walking ability with a trend toward increased compensatory contralesional CRP based control. Conclusion Both CST and CRP are involved with control of modules during walking and damage to both may lead to greater reliance on the contralesional CRP, which may contribute to a two-module pattern and be associated with worse walking performance.
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Affiliation(s)
- Shraddha Srivastava
- Ralph H. Johnson VA Medical Center, Charleston, SC, United States,Department of Health Sciences and Research, College of Health Professions, Medical University of South Carolina, Charleston, SC, United States,*Correspondence: Shraddha Srivastava
| | - Bryant A. Seamon
- Ralph H. Johnson VA Medical Center, Charleston, SC, United States,Department of Health Sciences and Research, College of Health Professions, Medical University of South Carolina, Charleston, SC, United States,Division of Physical Therapy, Department of Rehabilitation Sciences, College of Health Professions, Medical University of South Carolina, Charleston, SC, United States
| | - Barbara K. Marebwa
- Department of Neurology, College of Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Janina Wilmskoetter
- Department of Health Sciences and Research, College of Health Professions, Medical University of South Carolina, Charleston, SC, United States
| | - Mark G. Bowden
- Ralph H. Johnson VA Medical Center, Charleston, SC, United States,Department of Health Sciences and Research, College of Health Professions, Medical University of South Carolina, Charleston, SC, United States,Division of Physical Therapy, Department of Rehabilitation Sciences, College of Health Professions, Medical University of South Carolina, Charleston, SC, United States
| | - Chris M. Gregory
- Ralph H. Johnson VA Medical Center, Charleston, SC, United States,Department of Health Sciences and Research, College of Health Professions, Medical University of South Carolina, Charleston, SC, United States,Division of Physical Therapy, Department of Rehabilitation Sciences, College of Health Professions, Medical University of South Carolina, Charleston, SC, United States
| | - Na Jin Seo
- Ralph H. Johnson VA Medical Center, Charleston, SC, United States,Department of Health Sciences and Research, College of Health Professions, Medical University of South Carolina, Charleston, SC, United States,Division of Occupational Therapy, College of Health Professions, Medical University of South Carolina, Charleston, SC, United States
| | - Colleen A. Hanlon
- Department of Cancer Biology, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Leonardo Bonilha
- Department of Neurology, College of Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Truman R. Brown
- Department of Radiology and Radiological Science, College of Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Richard R. Neptune
- Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX, United States
| | - Steven A. Kautz
- Ralph H. Johnson VA Medical Center, Charleston, SC, United States,Department of Health Sciences and Research, College of Health Professions, Medical University of South Carolina, Charleston, SC, United States,Division of Physical Therapy, Department of Rehabilitation Sciences, College of Health Professions, Medical University of South Carolina, Charleston, SC, United States
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Afzal T, Zhu F, Tseng SC, Lincoln JA, Francisco GE, Su H, Chang SH. Evaluation of Muscle Synergy during Exoskeleton-assisted Walking in Persons with Multiple Sclerosis. IEEE Trans Biomed Eng 2022; 69:3265-3274. [PMID: 35412969 DOI: 10.1109/tbme.2022.3166705] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVE Gait deficit after multiple sclerosis (MS) can be characterized by altered muscle activation patterns. There is preliminary evidence of improved walking with a lower limb exoskeleton in persons with MS. However, the effects of exoskeleton-assisted walking on neuromuscular modifications are relatively unclear. The objective of this study was to investigate the muscle synergies, their activation patterns and the differences in neural strategies during walking with (EXO) and without (No-EXO) an exoskeleton. METHODS Ten subjects with MS performed walking during EXO and No-EXO conditions. Electromyography signals from seven leg muscles were recorded. Muscle synergies and the activation profiles were extracted using non-negative matrix factorization. RESULTS The stance phase duration was significantly shorter during EXO compared to the No-EXO condition (p<0.05). Moreover, typically 3-5 modules were extracted in each condition. The module-1 (comprising Vastus Medialis and Rectus Femoris muscles), module-2 (comprising Soleus and Medial Gastrocnemius muscles), module-3 (Tibialis Anterior muscle) and module-4 (comprising Biceps Femoris and Semitendinosus muscles) were comparable between conditions. During EXO condition, Semitendinosus and Vastus Medialis emerged in module-5 in 7/10 subjects. Compared to No-EXO, average activation amplitude was significantly reduced corresponding to module-2 during the stance phase and module-3 during the swing phase during EXO. CONCLUSION Exoskeleton-assistance does not alter the existing synergy modules, but could induce a new module to emerge, and alters the control of these modules, i.e., modifies the neural commands indicated by the reduced amplitude of the activation profiles.
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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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Merged swing-muscle synergies and their relation to walking characteristics in subacute post-stroke patients: An observational study. PLoS One 2022; 17:e0263613. [PMID: 35120178 PMCID: PMC8815905 DOI: 10.1371/journal.pone.0263613] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 01/21/2022] [Indexed: 11/19/2022] Open
Abstract
In post-stroke patients, muscle synergy (the coordination of motor modules during walking) is impaired. In some patients, the muscle synergy termed module 1 (hip/knee extensors) is merged with module 2 (ankle plantar flexors), and in other cases, module 1 is merged with module 4 (knee flexors). However, post-stroke individuals with a merging pattern of module 3 (hip flexor and ankle dorsiflexor) and module 4, which is the swing-muscle synergy, have not been reported. This study aimed to determine the muscle-synergy merging subtypes of post-stroke during comfortable walking speed (cws). We also examined the effect of experimental lower-limb angle modulation on the muscle synergy patterns of walking in each subtype. Forty-one participants were assessed under three conditions: cws, long stepping on the paretic side (p-long), and long stepping on the non-paretic side (np-long). Lower-limb flexion and extension angles and the electromyogram were measured during walking. Subtype classification was based on the merging pattern of the muscle synergies, and we examined the effect of different lower-limb angles on the muscle synergies. We identified three merging subtypes: module 1 with module 2 (subtype 1), module 1 with module 4 (subtype 2), and module 3 with module 4 (subtype 3). In the cws condition, the lower-limb flexion angle was reduced in subtype 3, and the lower-limb extension angle was decreased in subtype 1. A more complex muscle synergy was observed only in subtype 3 in the p-long condition versus cws (p = 0.036). This subtype classification of walking impairments based on the merging pattern of the muscle synergies could be useful for the selection of a rehabilitation strategy according to the individual’s particular neurological condition. Rehabilitation with increased lower-limb flexion may be effective for the training of patients with merging of modules 3 and 4 in comfortable walking.
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Mizuta N, Hasui N, Nishi Y, Higa Y, Matsunaga A, Deguchi J, Yamamoto Y, Nakatani T, Taguchi J, Morioka S. Association between temporal asymmetry and muscle synergy during walking with rhythmic auditory cueing in stroke survivors living with impairments. Arch Rehabil Res Clin Transl 2022; 4:100187. [PMID: 35756980 PMCID: PMC9214337 DOI: 10.1016/j.arrct.2022.100187] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We examined the effect of temporal gait asymmetry on muscle synergy post stroke. In our design, the temporal asymmetry during gait was experimentally modulated. The temporal asymmetry was modulated using rhythmic auditory cueing. Rhythmic auditory cueing with gait immediately improved temporal asymmetry and muscle synergy deficits. The temporal asymmetry affected muscle synergy more than kinematics.
Objective To examine the relationship between temporal asymmetry and complexity of muscle synergy during walking using rhythmic auditory cueing (RAC) and the factors related to changes in muscle synergy during walking with RAC in survivors of stroke. Design Cross-sectional study. Setting Wards at 2 medical corporation hospitals. Participants Forty survivors of stroke (N=40; mean age, 70.4±10.3 years; time since stroke, 72.2±32.3 days) who could walk without physical assistance. Interventions Not applicable. Main Outcome Measures The participants were assessed in a random block design under 2 conditions: comfortable walking speed (CWS) and walking with RAC. Single-leg support time, kinematics, and electromyograms were measured. Factors related to the complexity of muscle synergy (variance accounted for by 1 synergy [VAF1]) between the walking conditions were examined using hierarchical multiple regression analysis. Results In the RAC condition, lower limb flexion and knee flexion angles, single-leg support time on the paretic side, and the symmetry index of single-leg support time were increased compared with those in the CWS condition. VAF1 was decreased in the RAC condition (73.9±0.15) compared with that in the CWS condition (76.9±0.13, P=.002). Hierarchical multiple regression analysis revealed that the change in VAF1 was explained by change in single-leg support time (R2=0.43, P=.002). Conclusions The RAC condition demonstrated a more complex representation of muscle synergy than the CWS condition; the change in single-leg support time on the paretic side related to the changes in muscle synergy more than changes in lower limb angle. These findings can help in the walking-training concept to improve muscle synergy deficits in survivors of stroke.
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Affiliation(s)
- Naomichi Mizuta
- Department of Neurorehabilitation, Graduate School of Health Sciences, Kio University, Nara, Japan
- Department of Therapy, Takarazuka Rehabilitation Hospital (SHOWAKAI Medical Corporation), Takarazuka, Japan
- Corresponding author Naomichi Mizuta, PT, PhD, Department of Neurorehabilitation, Graduate School of Health Sciences, Kio University, 4-2-2 Umaminaka, Koryo, Kitakatsuragi-gun, Nara, 635-0832, Japan.
| | - Naruhito Hasui
- Department of Therapy, Takarazuka Rehabilitation Hospital (SHOWAKAI Medical Corporation), Takarazuka, Japan
| | - Yuki Nishi
- Department of Neurorehabilitation, Graduate School of Health Sciences, Kio University, Nara, Japan
| | - Yasutaka Higa
- Department of Therapy, Takarazuka Rehabilitation Hospital (SHOWAKAI Medical Corporation), Takarazuka, Japan
| | - Ayaka Matsunaga
- Department of Therapy, Takarazuka Rehabilitation Hospital (SHOWAKAI Medical Corporation), Takarazuka, Japan
| | - Junji Deguchi
- Department of Rehabilitation, Nakazuyagi Hospital (HIMAWARIKAI Medical Corporation), Tokushima, Japan
| | - Yasutada Yamamoto
- Department of Therapy, Takarazuka Rehabilitation Hospital (SHOWAKAI Medical Corporation), Takarazuka, Japan
| | - Tomoki Nakatani
- Department of Therapy, Takarazuka Rehabilitation Hospital (SHOWAKAI Medical Corporation), Takarazuka, Japan
| | - Junji Taguchi
- Department of Therapy, Takarazuka Rehabilitation Hospital (SHOWAKAI Medical Corporation), Takarazuka, Japan
| | - Shu Morioka
- Department of Neurorehabilitation, Graduate School of Health Sciences, Kio University, Nara, Japan
- Neurorehabilitation Research Center, Kio University, Nara, Japan
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11
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Zhu F, Kern M, Fowkes E, Afzal T, Contreras-Vidal JL, Francisco GE, Chang SH. Effects of an exoskeleton-assisted gait training on post-stroke lower-limb muscle coordination. J Neural Eng 2021; 18. [PMID: 33752175 DOI: 10.1088/1741-2552/abf0d5] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 03/22/2021] [Indexed: 11/11/2022]
Abstract
Objective.Powered exoskeletons have been used to help persons with gait impairment regain some walking ability. However, little is known about its impact on neuromuscular coordination in persons with stroke. The objective of this study is to investigate how a powered exoskeleton could affect the neuromuscular coordination of persons with post-stroke hemiparesis.Approach.Eleven able-bodied subjects and ten stroke subjects participated in a single-visit treadmill walking assessment, in which their motion and lower-limb muscle activities were captured. By comparing spatiotemporal parameters, kinematics, and muscle synergy pattern between two groups, we characterized the normal gait pattern and the post-stroke motor deficits. Five eligible stroke subjects received exoskeleton-assisted gait trainings and walking assessments were conducted pre-intervention (Pre) and post-intervention (Post), without (WO) and with (WT) the exoskeleton. We compared their gait performance between (a) Pre and Post to investigate the effect of exoskeleton-assisted gait training and, (b) WO and WT the exoskeleton to investigate the effect of exoskeleton wearing on stroke subjects.Main results.While four distinct motor modules were needed to describe lower-extremity activities during stead-speed walking among able-bodied subjects, three modules were sufficient for the paretic leg from the stroke subjects. Muscle coordination complexity, module composition and activation timing were preserved after the training, indicating the intervention did not significantly change the neuromuscular coordination. In contrast, walking WT the exoskeleton altered the stroke subjects' synergy pattern, especially on the paretic side. The changes were dominated by the activation profile modulation towards the normal pattern observed from the able-bodied group.Significance.This study gave us some critical insight into how a powered exoskeleton affects the stroke subjects' neuromuscular coordination during gait and demonstrated the potential to use muscle synergy as a method to evaluate the effect of the exoskeleton training.This study was registered at ClinicalTrials.gov (identifier: NCT03057652).
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Affiliation(s)
- Fangshi Zhu
- Department of Physical Medicine and Rehabilitation, The University of Texas Health Science Center at Houston, Houston, TX, United States of America.,Center for Wearable Exoskeletons, NeuroRecovery Research Center, TIRR Memorial Hermann, Houston, TX, United States of America
| | - Marcie Kern
- Center for Wearable Exoskeletons, NeuroRecovery Research Center, TIRR Memorial Hermann, Houston, TX, United States of America
| | - Erin Fowkes
- Center for Wearable Exoskeletons, NeuroRecovery Research Center, TIRR Memorial Hermann, Houston, TX, United States of America
| | - Taimoor Afzal
- Department of Physical Medicine and Rehabilitation, The University of Texas Health Science Center at Houston, Houston, TX, United States of America.,Center for Wearable Exoskeletons, NeuroRecovery Research Center, TIRR Memorial Hermann, Houston, TX, United States of America
| | - Jose-Luis Contreras-Vidal
- Department of Electrical and Computer Engineering, The University of Houston, Houston, TX, United States of America
| | - Gerard E Francisco
- Department of Physical Medicine and Rehabilitation, The University of Texas Health Science Center at Houston, Houston, TX, United States of America.,Center for Wearable Exoskeletons, NeuroRecovery Research Center, TIRR Memorial Hermann, Houston, TX, United States of America
| | - Shuo-Hsiu Chang
- Department of Physical Medicine and Rehabilitation, The University of Texas Health Science Center at Houston, Houston, TX, United States of America.,Center for Wearable Exoskeletons, NeuroRecovery Research Center, TIRR Memorial Hermann, Houston, TX, United States of America
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12
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Lewallen LK, Srivastava S, Kautz SA, Neptune RR. Assessment of turning performance and muscle coordination in individuals post-stroke. J Biomech 2020; 114:110113. [PMID: 33338757 DOI: 10.1016/j.jbiomech.2020.110113] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 09/28/2020] [Accepted: 10/29/2020] [Indexed: 11/17/2022]
Abstract
Turning is an important activity of daily living and often compromised post-stroke. The fall rate for individuals post-stroke while turning is nearly four times as high compared to healthy adults, with most falls resulting in injury. Thus, there is a need for evidence-based rehabilitation targets to improve turning performance for individuals post-stroke. To produce well-coordinated movements, muscles can be organized into muscle modules (i.e., groups of co-excited muscles). Post-stroke these modules can be merged, leading to impaired muscle coordination and walking performance. However, the relationship between impaired coordination and turning performance is not well understood. Thus, the purpose of this study was to analyze the influence of impaired muscle coordination (i.e., merged modules) on turning performance (i.e., time and number of steps required to complete a turn, and smoothness and balance control during the turn). Individuals post-stroke and healthy controls performed three tasks including overground straight-line walking, a 90-degree turn, and a 180-degree turn. The number of muscle modules during straight-line walking were determined using non-negative matrix factorization. During 180-degree turning, those with two modules took longer to turn, used more steps and had less smooth movement. Those with reduced module complexity exhibited diminished balance control during both 90-degree and 180-degree turning. These results suggest obtaining independent modules should be an important aim in locomotor therapies aimed at improving turning performance. In addition, the time it takes to complete a 180-degree turn may provide useful clinical insight into impaired muscle coordination post-stroke.
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Affiliation(s)
- Lindsey K Lewallen
- Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Shraddha Srivastava
- Department of Health Sciences and Research, College of Health Professions, Medical University of South Carolina, Charleston, SC, USA
| | - Steven A Kautz
- Ralph H. Johnson VA Medical Center, Charleston, SC, USA; Department of Health Sciences and Research, College of Health Professions, Medical University of South Carolina, Charleston, SC, USA
| | - Richard R Neptune
- Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX, USA.
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13
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Santuz A, Ekizos A, Kunimasa Y, Kijima K, Ishikawa M, Arampatzis A. Lower complexity of motor primitives ensures robust control of high-speed human locomotion. Heliyon 2020; 6:e05377. [PMID: 33163662 PMCID: PMC7610320 DOI: 10.1016/j.heliyon.2020.e05377] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 07/15/2020] [Accepted: 10/27/2020] [Indexed: 01/06/2023] Open
Abstract
Walking and running are mechanically and energetically different locomotion modes. For selecting one or another, speed is a parameter of paramount importance. Yet, both are likely controlled by similar low-dimensional neuronal networks that reflect in patterned muscle activations called muscle synergies. Here, we challenged human locomotion by having our participants walk and run at a very broad spectrum of submaximal and maximal speeds. The synergistic activations of lower limb locomotor muscles were obtained through decomposition of electromyographic data via non-negative matrix factorization. We analyzed the duration and complexity (via fractal analysis) over time of motor primitives, the temporal components of muscle synergies. We found that the motor control of high-speed locomotion was so challenging that the neuromotor system was forced to produce wider and less complex muscle activation patterns. The motor modules, or time-independent coefficients, were redistributed as locomotion speed changed. These outcomes show that humans cope with the challenges of high-speed locomotion by adapting the neuromotor dynamics through a set of strategies that allow for efficient creation and control of locomotion.
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Affiliation(s)
- Alessandro Santuz
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
- Berlin School of Movement Science, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
| | - Antonis Ekizos
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
- Berlin School of Movement Science, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
| | - Yoko Kunimasa
- Graduate School of Sport and Exercise Sciences, Osaka University of Health and Sport Sciences, 590-0459 Osaka, Japan
| | - Kota Kijima
- Graduate School of Sport and Exercise Sciences, Osaka University of Health and Sport Sciences, 590-0459 Osaka, Japan
| | - Masaki Ishikawa
- Graduate School of Sport and Exercise Sciences, Osaka University of Health and Sport Sciences, 590-0459 Osaka, Japan
| | - Adamantios Arampatzis
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
- Berlin School of Movement Science, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
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14
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Jonsdottir J, Lencioni T, Gervasoni E, Crippa A, Anastasi D, Carpinella I, Rovaris M, Cattaneo D, Ferrarin M. Improved Gait of Persons With Multiple Sclerosis After Rehabilitation: Effects on Lower Limb Muscle Synergies, Push-Off, and Toe-Clearance. Front Neurol 2020; 11:668. [PMID: 32793100 PMCID: PMC7393214 DOI: 10.3389/fneur.2020.00668] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Accepted: 06/03/2020] [Indexed: 12/25/2022] Open
Abstract
Introduction: Persons with MS (PwMS) have markedly reduced push-off and toe-clearance during gait compared to healthy subjects (HS). These deficits may result from alterations in neuromotor control at the ankle. To optimize rehabilitation interventions for PwMS, a crucial step is to evaluate if and how altered neuromotor control, as represented by muscle synergies, improves with rehabilitation. In this study we investigated changes in ankle motor control and associated biomechanical parameters during gait in PwMS, occurring with increase in speed after gait rehabilitation. Methods: 3D motion and EMG data were collected while 11 PwMS (age 50.3 + 11.1; EDSS 5.2 + 1.2) walked overground at self-selected speed before (T0) and after 20 sessions (T1) of intensive treadmill training. Muscle synergies were extracted using non-negative matrix factorization. Gait parameters were computed according to the LAMB protocol. Pearson's correlation coefficient was used to evaluate the similarity of motor modules between PwMS and HS. To assess differences in distal module activations representing neuromotor control at the ankle [Forward Propulsion (FPM) and Ground Clearance modules (GCM)], each module's activation timing was integrated over 100% of the gait cycle and the activation percentage index (API) was computed in six phases. Ten age matched HS provided two separate speed-matched normative datasets for T0 and T1. For speed independent comparison for the PwMs Z scores were calculated for all their gait variables. Results: In PwMS velocity increased significantly from T0 to T1 (0.74-0.90 m/s, p < 0.05). The activation profiles (API) of FPM and GCM of PwMS improved in pre-swing (p < 0.05): FPM (Mean [95% CI] [%]: T0: 12.5 [5.7-19.3] vs. T1: 9.0 [2.7-15.3]); GCM (T0: 26.7 [18.2-35.3] vs. T1: 24.5 [18.2-30.7]). This was associated with an increase in toe clearance (80.3 to 103.6 mm, p < 0.05) and a higher ankle power peak in pre-swing (1.53-1.93 W/kg, p < 0.05). Conclusion: Increased gait speed of PwMS after intensive gait training was consistent with improvements in spatio-temporal gait parameters. The most important finding of this study was the re-organization of distal leg modules related to neurophysiological changes induced by rehabilitation. This was associated with an improved ankle performance.
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15
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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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16
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Tan CK, Kadone H, Watanabe H, Marushima A, Hada Y, Yamazaki M, Sankai Y, Matsumura A, Suzuki K. Differences in Muscle Synergy Symmetry Between Subacute Post-stroke Patients With Bioelectrically-Controlled Exoskeleton Gait Training and Conventional Gait Training. Front Bioeng Biotechnol 2020; 8:770. [PMID: 32850696 PMCID: PMC7403486 DOI: 10.3389/fbioe.2020.00770] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 06/18/2020] [Indexed: 12/22/2022] Open
Abstract
Understanding the reorganization of the central nervous system after stroke is an important endeavor in order to design new therapies in gait training for stroke patients. Current clinical evaluation scores and gait velocity are insufficient to describe the state of the nervous system, and one aspect where this is lacking is in the quantification of gait symmetry. Previous studies have pointed out that spatiotemporal gait asymmetries are commonly observed in stroke patients with hemiparesis. Such asymmetries are known to cause long-term complications like joint pain and deformation. Recent studies also indicate that spatiotemporal measures showed that gait symmetry worsens after discharge from therapy. This study shows that muscle synergy analysis can be used to quantify gait symmetry and compliment clinical measures. Surface EMG was collected from lower limb muscles of subacute post-stroke patients (with an onset of around 14 days) from two groups, one undergoing robotic-assisted therapy (known as HAL group) and the other undergoing conventional therapy (known as Control group). Muscle synergies from the paretic and non-paretic limb were extracted with Non-Negative Matrix Factorization (NNMF) and compared with each other to obtain a gait symmetry index over therapy sessions. Gait events were tracked with motion tracking (for the HAL group) or foot pressure sensors (for the conventional therapy group). Patients from both groups were assessed over a 3-weeks long gait training program. Results indicated that there were no differences in muscle synergy symmetry for both groups of patients. However, the timing of muscle synergies were observed to be symmetrical in the HAL group, but not for the Control group. Intergroup comparisons of symmetry in muscle synergies and their timings were not significantly different. This could be due to a large variability in recovery in the Control group. Finally, stance time ratio was not observed to improve in both groups after their respective therapies. Interestingly, FIM and FMA scores of both groups were observed to improve after their respective therapies. Analysis of muscle coordination could reveal mechanisms of gait symmetry which could otherwise be difficult to observe with clinical scores.
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Affiliation(s)
- Chun Kwang Tan
- Artificial Intelligence Laboratory, University of Tsukuba, Tsukuba, Japan.,Faculty of Engineering, Information and Systems, University of Tsukuba, Tsukuba, Japan
| | - Hideki Kadone
- Center for Innovative Medicine and Engineering, University of Tsukuba Hospital, Tsukuba, Japan.,Center for Cybernics Research, University of Tsukuba, Tsukuba, Japan
| | - Hiroki Watanabe
- Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Aiki Marushima
- Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Yasushi Hada
- Department of Rehabilitation Medicine, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Masashi Yamazaki
- Department of Orthopaedic Surgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Yoshiyuki Sankai
- Faculty of Engineering, Information and Systems, University of Tsukuba, Tsukuba, Japan.,Center for Cybernics Research, University of Tsukuba, Tsukuba, Japan
| | - Akira Matsumura
- Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Kenji Suzuki
- Artificial Intelligence Laboratory, University of Tsukuba, Tsukuba, Japan.,Faculty of Engineering, Information and Systems, University of Tsukuba, Tsukuba, Japan.,Center for Cybernics Research, University of Tsukuba, Tsukuba, Japan
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17
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Stirling L, Kelty-Stephen D, Fineman R, Jones MLH, Daniel Park BK, Reed MP, Parham J, Choi HJ. Static, Dynamic, and Cognitive Fit of Exosystems for the Human Operator. HUMAN FACTORS 2020; 62:424-440. [PMID: 32004106 DOI: 10.1177/0018720819896898] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
OBJECTIVE To define static, dynamic, and cognitive fit and their interactions as they pertain to exosystems and to document open research needs in using these fit characteristics to inform exosystem design. BACKGROUND Initial exosystem sizing and fit evaluations are currently based on scalar anthropometric dimensions and subjective assessments. As fit depends on ongoing interactions related to task setting and user, attempts to tailor equipment have limitations when optimizing for this limited fit definition. METHOD A targeted literature review was conducted to inform a conceptual framework defining three characteristics of exosystem fit: static, dynamic, and cognitive. Details are provided on the importance of differentiating fit characteristics for developing exosystems. RESULTS Static fit considers alignment between human and equipment and requires understanding anthropometric characteristics of target users and geometric equipment features. Dynamic fit assesses how the human and equipment move and interact with each other, with a focus on the relative alignment between the two systems. Cognitive fit considers the stages of human-information processing, including somatosensation, executive function, and motor selection. Human cognitive capabilities should remain available to process task- and stimulus-related information in the presence of an exosystem. Dynamic and cognitive fit are operationalized in a task-specific manner, while static fit can be considered for predefined postures. CONCLUSION A deeper understanding of how an exosystem fits an individual is needed to ensure good human-system performance. Development of methods for evaluating different fit characteristics is necessary. APPLICATION Methods are presented to inform exosystem evaluation across physical and cognitive characteristics.
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Affiliation(s)
| | | | - Richard Fineman
- 2167 Harvard-MIT Health Science and Technology Program, Cambridge, MA, USA
| | - Monica L H Jones
- 1259 University of Michigan Transportation Research Institute, Ann Arbor, USA
| | | | - Matthew P Reed
- 1259 University of Michigan Transportation Research Institute, Ann Arbor, USA
| | - Joseph Parham
- 155353 U.S. Army Combat Capabilities Development Command Soldier Center, Natick, MA, USA
| | - Hyeg Joo Choi
- 155353 U.S. Army Combat Capabilities Development Command Soldier Center, Natick, MA, USA
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18
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Khatkova SE, Kostenko EV, Akulov MA, Diagileva VP, Nikolaev EA, Orlova AS. [Modern aspects of the pathophysiology of walking disorders and their rehabilitation in post-stroke patients]. Zh Nevrol Psikhiatr Im S S Korsakova 2020; 119:43-50. [PMID: 32207717 DOI: 10.17116/jnevro201911912243] [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: 11/17/2022]
Abstract
The problem of rehabilitation of post-stroke patients with motor deficit remains relevant with growing prevalence of disability and decreasing mortality, despite all measures aimed at stroke prevention and morbidity reduction. One of the most common consequences of stroke is gait impairment as a result of spastic paresis of the lower limb (decreased gait velocity, shortened step, excessive loading of intact limb etc.), which leads to significant maladaptation, increased risk of falls, decrease in quality of life. The article presents a detailed review of motor action in normal and pathologic conditions, analysis of neuronal structures involved into a movement act in healthy individuals and in stroke patients, current aspects of gait pathophysiology, characteristics of post-stroke gait (speed and asymmetry of gain, balance control impairment). A separate paragraph is devoted to gait recovery after stroke with analysis of existing and developing strategies of rehabilitation, aimed at the improvement of vertical posture, balance control and movement, condition, tone and functioning of skeletal muscles. Authors also analyze new research information on the efficacy of botulinum toxin preparations and programs of Guided Self-Rehabilitation Contracts (GSC), present the results of clinical trials demonstrating the efficacy of combination of these two methods.
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Affiliation(s)
- S E Khatkova
- Medical and Rehabilitation Center, Moscow, Russia; State Research Center - Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Moscow, Russia
| | - E V Kostenko
- Burdenko National Scientific and Practical Centre for Neurosurgery, Moscow, Russia
| | - M A Akulov
- Pirogov Russian National Research Medical University, Moscow, Russia
| | - V P Diagileva
- Medical and Rehabilitation Center, Moscow, Russia; State Research Center - Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Moscow, Russia
| | - E A Nikolaev
- Medical and Rehabilitation Center, Moscow, Russia; State Research Center - Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Moscow, Russia
| | - A S Orlova
- Sechenov First Moscow State Medical University, Moscow, Russia
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19
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Age-Related Differences in Muscle Synergy Organization during Step Ascent at Different Heights and Directions. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10061987] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The aim of this study was to explore the underlying age-related differences in dynamic motor control during different step ascent conditions using muscle synergy analysis. Eleven older women (67.0 y ± 2.5) and ten young women (22.5 y ± 1.6) performed stepping in forward and lateral directions at step heights of 10, 20 and 30 cm. Surface electromyography was obtained from 10 lower limb and torso muscles. Non-negative matrix factorization was used to identify sets of (n) synergies across age groups and stepping conditions. In addition, variance accounted for (VAF) by the detected number of synergies was compared to assess complexity of motor control. Finally, correlation coefficients of muscle weightings and between-subject variability of the temporal activation patterns were calculated and compared between age groups and stepping conditions. Four synergies accounted for >85% VAF across age groups and stepping conditions. Age and step height showed a significant negative correlation with VAF during forward stepping but not lateral stepping, with lower VAF indicating higher synergy complexity. Muscle weightings showed higher similarity across step heights in older compared to young women. Neuromuscular control of young and community-dwelling older women could not be differentiated based on the number of synergies extracted. Additional analyses of synergy structure and complexity revealed subtle age- and step-height-related differences, indicating that older women rely on more complex neuromuscular control strategies.
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20
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Booth ATC, van der Krogt MM, Harlaar J, Dominici N, Buizer AI. Muscle Synergies in Response to Biofeedback-Driven Gait Adaptations in Children With Cerebral Palsy. Front Physiol 2019; 10:1208. [PMID: 31611807 PMCID: PMC6776587 DOI: 10.3389/fphys.2019.01208] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 09/04/2019] [Indexed: 12/26/2022] Open
Abstract
Background Children with cerebral palsy (CP) often show impaired selective motor control (SMC) that induces limitations in motor function. Children with CP can improve aspects of pathological gait in an immediate response to visual biofeedback. It is not known, however, how these gait adaptations are achieved at the neural level, nor do we know the extent of SMC plasticity in CP. Aim Investigate the underlying SMC and changes that may occur when gait is adapted with biofeedback. Methods Twenty-three ambulatory children with CP and related (hereditary) forms of spastic paresis (Aged: 10.4 ± 3.1, 6–16 years, M: 16/F: 9) were challenged with real-time biofeedback to improve step length, knee extension, and ankle power while walking on an instrumented treadmill in a virtual reality environment. The electromyograms of eight superficial muscles of the leg were analyzed and synergies were further decomposed using non-negative matrix factorization (NNMF) using 1 to 5 synergies, to quantify SMC. Total variance accounted for (tVAF) was used as a measure of synergy complexity. An imposed four synergy solution was investigated further to compare similarity in weightings and timing patterns of matched paired synergies between baseline and biofeedback trials. Results Despite changes in walking pattern, changes in synergies were limited. The number of synergies required to explain at least 90% of muscle activation increased significantly, however, the change in measures of tVAF1 from baseline (0.75 ± 0.08) were less than ±2% between trials. In addition, within-subject similarity of synergies to baseline walking was high (>0.8) across all biofeedback trials. Conclusion These results suggest that while gait may be adapted in an immediate response, SMC as quantified by synergy analysis is perhaps more rigidly impaired in CP. Subtle changes in synergies were identified; however, it is questionable if these are clinically meaningful at the level of an individual. Adaptations may be limited in the short term, and further investigation is essential to establish if long term training using biofeedback leads to adapted SMC.
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Affiliation(s)
- Adam T C Booth
- Department of Rehabilitation Medicine, Amsterdam Movement Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands.,Department of Clinical Applications and Research, Motek Medical BV, Amsterdam, Netherlands
| | - Marjolein M van der Krogt
- Department of Rehabilitation Medicine, Amsterdam Movement Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Jaap Harlaar
- Department of Rehabilitation Medicine, Amsterdam Movement Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands.,Department of Biomechanical Engineering, Delft University of Technology, Delft, Netherlands
| | - Nadia Dominici
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Institute for Brain and Behavior Amsterdam & Amsterdam Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Annemieke I Buizer
- Department of Rehabilitation Medicine, Amsterdam Movement Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
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21
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Allen JL, Kesar TM, Ting LH. Motor module generalization across balance and walking is impaired after stroke. J Neurophysiol 2019; 122:277-289. [PMID: 31066611 DOI: 10.1152/jn.00561.2018] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Muscle coordination is often impaired after stroke, leading to deficits in the control of walking and balance. In this study, we examined features of muscle coordination associated with reduced walking performance in chronic stroke survivors using motor module (a.k.a. muscle synergy) analysis. We identified differences between stroke survivors and age-similar neurotypical controls in the modular control of both overground walking and standing reactive balance. In contrast to previous studies that demonstrated reduced motor module number poststroke, our cohort of stroke survivors did not exhibit a reduction in motor module number compared with controls during either walking or reactive balance. Instead, the pool of motor modules common to walking and reactive balance was smaller, suggesting reduced generalizability of motor module function across behaviors. The motor modules common to walking and reactive balance tended to be less variable and more distinct, suggesting more reliable output compared with motor modules specific to either behavior. Greater motor module generalization in stroke survivors was associated with faster walking speed, more normal step length asymmetry, and narrower step widths. Our work is the first to show that motor module generalization across walking and balance may help to distinguish important and clinically relevant differences in walking performance across stroke survivors that would have been overlooked by examining only a single behavior. Finally, because similar relationships between motor module generalization and walking performance have been demonstrated in healthy young adults and individuals with Parkinson's disease, this suggests that motor module generalization across walking and balance may be important for well-coordinated walking. NEW & NOTEWORTHY This is the first work to simultaneously examine neuromuscular control of walking and standing reactive balance in stroke survivors. We show that motor module generalization across these behaviors (i.e., recruiting common motor modules) is reduced compared with controls and is associated with slower walking speeds, asymmetric step lengths, and larger step widths. This is true despite no between-group differences in module number, suggesting that motor module generalization across walking and balance is important for well-coordinated walking.
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Affiliation(s)
- Jessica L Allen
- Department of Chemical and Biomedical Engineering, West Virginia University , Morgantown, West Virginia
| | - Trisha M Kesar
- Department of Rehabilitation Medicine, Division of Physical Therapy, Emory University School of Medicine , Atlanta, Georgia
| | - Lena H Ting
- Department of Rehabilitation Medicine, Division of Physical Therapy, Emory University School of Medicine , Atlanta, Georgia.,Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology , Atlanta, Georgia
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22
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Cheng R, Sui Y, Sayenko D, Burdick JW. Motor Control After Human SCI Through Activation of Muscle Synergies Under Spinal Cord Stimulation. IEEE Trans Neural Syst Rehabil Eng 2019; 27:1331-1340. [PMID: 31056504 DOI: 10.1109/tnsre.2019.2914433] [Citation(s) in RCA: 10] [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
Spinal cord stimulation (SCS) has enabled motor recovery in paraplegics with motor complete spinal cord injury (SCI). However, the physiological mechanisms underlying this recovery are unknown. This paper analyzes muscle synergies in two motor complete SCI patients under SCS during standing and compares them with muscle synergies in healthy subjects, in order to help elucidate the mechanisms that enable motor control through SCS. One challenge is that standard muscle synergy extraction algorithms, such as non-negative matrix factorization (NMF), fail when applied to SCI patients under SCS. We develop a new algorithm-rShiftNMF-to extract muscle synergies in these cases. We find muscle synergies extracted by rShiftNMF are significantly better at interpreting electromyography (EMG) activity, and resulting synergy features are more physiologically meaningful. By analyzing muscle synergies from SCI patients and healthy subjects, we find that: 1) SCI patients rely significantly on muscle synergy activation to generate motor activity; 2) interleaving SCS can selectively activate an additional muscle synergy that is critical to SCI standing; and 3) muscle synergies extracted from SCI patients under SCS differ substantially from those extracted from healthy subjects. We provide evidence that after spinal cord injury, SCS influences motor function through muscle synergy activation.
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23
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Martino G, Ivanenko Y, Serrao M, Ranavolo A, Draicchio F, Casali C, Lacquaniti F. Locomotor coordination in patients with Hereditary Spastic Paraplegia. J Electromyogr Kinesiol 2019; 45:61-69. [PMID: 30836301 DOI: 10.1016/j.jelekin.2019.02.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 02/14/2019] [Accepted: 02/18/2019] [Indexed: 10/27/2022] Open
Abstract
Locomotion is a complex behaviour that requires the coordination of multiple body segments and muscle groups. Here we investigated how the weakness and spasticity in individuals with Hereditary Spastic Paraplegia (HSP) affect the coordination patterns of the lower limbs. We analysed kinematics and electromyographic (EMG) activity from 12 leg muscles in 21 persons with HSP and 20 control subjects at matched walking speeds. To assess the locomotor coordination, we examined the covariation between thigh, shank and foot elevation angles by means of principal component analysis and the modular organization of EMG patterns using the non-negative matrix factorization algorithm. The characteristic features of the HSP gait consisted in changes of the elevation angles covariation, the shape of the gait loop, reduced range of motion of the distal segments and significantly lower foot lift. The EMG factorization analysis revealed a comparable structure of the motor output between HSP and control groups, but significantly wider basic temporal patterns associated with muscles innervated from the sacral spinal segments in HSP. Overall, the applied methodology highlighted the impact of the corticospinal degeneration and spasticity on the coordination of distal limb segments and basic muscle modules associated with distal spinal segments.
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Affiliation(s)
- G Martino
- Centre of Space Bio-medicine, University of Rome Tor Vergata, 00133 Rome, Italy; Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, 00179 Rome, Italy.
| | - Y Ivanenko
- Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, 00179 Rome, Italy
| | - M Serrao
- Rehabilitation Centre Policlinico Italia, 00162 Rome, Italy; Department of Medical and Surgical Sciences and Biotechnologies, Sapienza University of Rome, 04100 Latina, Italy
| | - A Ranavolo
- INAIL, Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Monte Porzio Catone, 00078 Rome, Italy
| | - F Draicchio
- INAIL, Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Monte Porzio Catone, 00078 Rome, Italy
| | - C Casali
- Department of Medical and Surgical Sciences and Biotechnologies, Sapienza University of Rome, 04100 Latina, Italy
| | - F Lacquaniti
- Centre of Space Bio-medicine, University of Rome Tor Vergata, 00133 Rome, Italy; Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, 00179 Rome, Italy; Department of Systems Medicine, University of Rome Tor Vergata, 00133 Rome, Italy
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24
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Santuz A, Ekizos A, Janshen L, Mersmann F, Bohm S, Baltzopoulos V, Arampatzis A. Modular Control of Human Movement During Running: An Open Access Data Set. Front Physiol 2018; 9:1509. [PMID: 30420812 PMCID: PMC6216155 DOI: 10.3389/fphys.2018.01509] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 10/08/2018] [Indexed: 12/31/2022] Open
Abstract
The human body is an outstandingly complex machine including around 1000 muscles and joints acting synergistically. Yet, the coordination of the enormous amount of degrees of freedom needed for movement is mastered by our one brain and spinal cord. The idea that some synergistic neural components of movement exist was already suggested at the beginning of the 20th century. Since then, it has been widely accepted that the central nervous system might simplify the production of movement by avoiding the control of each muscle individually. Instead, it might be controlling muscles in common patterns that have been called muscle synergies. Only with the advent of modern computational methods and hardware it has been possible to numerically extract synergies from electromyography (EMG) signals. However, typical experimental setups do not include a big number of individuals, with common sample sizes of 5 to 20 participants. With this study, we make publicly available a set of EMG activities recorded during treadmill running from the right lower limb of 135 healthy and young adults (78 males and 57 females). Moreover, we include in this open access data set the code used to extract synergies from EMG data using non-negative matrix factorization (NMF) and the relative outcomes. Muscle synergies, containing the time-invariant muscle weightings (motor modules) and the time-dependent activation coefficients (motor primitives), were extracted from 13 ipsilateral EMG activities using NMF. Four synergies were enough to describe as many gait cycle phases during running: weight acceptance, propulsion, early swing, and late swing. We foresee many possible applications of our data that we can summarize in three key points. First, it can be a prime source for broadening the representation of human motor control due to the big sample size. Second, it could serve as a benchmark for scientists from multiple disciplines such as musculoskeletal modeling, robotics, clinical neuroscience, sport science, etc. Third, the data set could be used both to train students or to support established scientists in the perfection of current muscle synergies extraction methods. All the data is available at Zenodo (doi: 10.5281/zenodo.1254380).
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Affiliation(s)
- Alessandro Santuz
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany.,Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Antonis Ekizos
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany.,Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Lars Janshen
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Falk Mersmann
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany.,Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Sebastian Bohm
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany.,Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Vasilios Baltzopoulos
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
| | - Adamantios Arampatzis
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany.,Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany
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25
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Allen JL, Franz JR. The motor repertoire of older adult fallers may constrain their response to balance perturbations. J Neurophysiol 2018; 120:2368-2378. [PMID: 30133380 DOI: 10.1152/jn.00302.2018] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Older adults are at a high risk of falls, and most falls occur during locomotor activities like walking. This study aimed to improve our understanding of changes in neuromuscular control associated with increased risk of falls in older adults in the presence of dynamic balance challenges during walking. Motor module (also known as muscle synergy) analyses identified changes in the neuromuscular recruitment of leg muscles during walking with and without perturbations designed to elicit the visual perception of lateral instability. During normal walking we found that a history of falls (but not age) was associated with reduced motor module complexity and that age (but not a history of falls) was associated with increased step-to-step variability of module recruitment timing. Furthermore, motor module complexity was unaltered in the presence of optical flow perturbations. The specific effects of a history of falls on leg muscle recruitment included an absence and/or inability to independently recruit motor modules normally recruited to perform biomechanical functions important for walking balance control. These results suggest that fallers do not recruit the appropriate motor modules necessary for well-coordinated walking balance control even in the presence of perturbations. The identified changes in the modular control of walking balance in older fallers may either represent a neural deficit that leads to poor balance control or a prior history of falls that results in a compensatory motor adaptation. In either case, our study provides initial evidence that a reduced motor repertoire in older adult fallers may be a constraint on their ability to appropriately respond to balance challenges during walking. NEW & NOTEWORTHY This is the first study to demonstrate a reduced motor repertoire during walking in older adults with a history of falls but without any overt neurological deficits. Furthermore, using virtual reality during walking to elicit the visual perception of lateral instability, we provide initial evidence that a reduced motor repertoire in older adult fallers may be a constraint on their ability to appropriately respond to balance challenges during walking.
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Affiliation(s)
- Jessica L Allen
- Department of Chemical and Biomedical Engineering, West Virginia University , Morgantown, West Virginia
| | - Jason R Franz
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University , Chapel Hill, North Carolina
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26
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Li S, Francisco GE, Zhou P. Post-stroke Hemiplegic Gait: New Perspective and Insights. Front Physiol 2018; 9:1021. [PMID: 30127749 PMCID: PMC6088193 DOI: 10.3389/fphys.2018.01021] [Citation(s) in RCA: 115] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 07/10/2018] [Indexed: 12/18/2022] Open
Abstract
Walking dysfunction occurs at a very high prevalence in stroke survivors. Human walking is a phenomenon often taken for granted, but it is mediated by complicated neural control mechanisms. The automatic process includes the brainstem descending pathways (RST and VST) and the intraspinal locomotor network. It is known that leg muscles are organized into modules to serve subtasks for body support, posture and locomotion. Major kinematic mechanisms are recognized to minimize the center of gravity (COG) displacement. Stroke leads to damage to motor cortices and their descending corticospinal tracts and subsequent muscle weakness. On the other hand, brainstem descending pathways and the intraspinal motor network are disinhibited and become hyperexcitable. Recent advances suggest that they mediate post-stroke spasticity and diffuse spastic synergistic activation. As a result of such changes, existing modules are simplified and merged, thus leading to poor body support and walking performance. The wide range and hierarchy of post-stroke hemiplegic gait impairments is a reflection of mechanical consequences of muscle weakness, spasticity, abnormal synergistic activation and their interactions. Given the role of brainstem descending pathways in body support and locomotion and post-stroke spasticity, a new perspective of understanding post-stroke hemiplegic gait is proposed. Its clinical implications for management of hemiplegic gait are discussed. Two cases are presented as clinical application examples.
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Affiliation(s)
- Sheng Li
- Department of Physical Medicine and Rehabilitation, University of Texas Health Science Center, Houston, TX, United States
- TIRR Memorial Hermann Research Center, TIRR Memorial Hermann, Houston, TX, United States
| | - Gerard E. Francisco
- Department of Physical Medicine and Rehabilitation, University of Texas Health Science Center, Houston, TX, United States
- TIRR Memorial Hermann Research Center, TIRR Memorial Hermann, Houston, TX, United States
| | - Ping Zhou
- Department of Physical Medicine and Rehabilitation, University of Texas Health Science Center, Houston, TX, United States
- TIRR Memorial Hermann Research Center, TIRR Memorial Hermann, Houston, TX, United States
- Guangdong Work Injury Rehabilitation Center, Guangzhou, China
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27
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Cheng R, Burdick JW. Extraction of Muscle Synergies in Spinal Cord Injured Patients. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2018; 2018:2623-2626. [PMID: 30440946 DOI: 10.1109/embc.2018.8512763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Muscle synergies encode motor activity as a linear superposition of multiple motor units composed of a temporal command exciting a specific network of muscles. This study examines muscle synergies derived from simple standing studies of a complete spinal cord injury (SCI) patient under epidural spinal stimulation. A popular technique for extracting these synergies from EMG data is non-negative matrix factorization (NNMF). However, standard NNMF algorithms do not allow for physiological delays for a neural signal to reach different muscles. These delays are prevalent in SCI patients under spinal stimulation, and so we propose a new algorithm (regularized ShiftNMF) to extract muscle synergies which account for signal delays. We find muscle synergies extracted by the regularized ShiftNMF algorithm are significantly better at reconstructing EMG activity, and the resulting features are physiologically consistent and more useful in describing patient behavior.
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28
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Using a Module-Based Analysis Framework for Investigating Muscle Coordination during Walking in Individuals Poststroke: A Literature Review and Synthesis. Appl Bionics Biomech 2018; 2018:3795754. [PMID: 29967653 PMCID: PMC6008620 DOI: 10.1155/2018/3795754] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 05/02/2018] [Indexed: 01/10/2023] Open
Abstract
Factorization methods quantitatively group electromyographic signals from several muscles during dynamic tasks into multiple modules where each module consists of muscles that are coactive during the movement. Module-based analyses may provide an analytical framework for testing theories of poststroke motor control recovery based on one's ability to move independently from mass flexion-extension muscle group coactivation. Such a framework may be useful for understanding the causality between underlying neural impairments, biomechanical function, and walking performance in individuals poststroke. Our aim is to synthesize current evidence regarding the relationships between modules, gait mechanics, and rehabilitation in individuals poststroke. We synthesized eleven studies that performed module-based analyses during walking tasks for individuals poststroke. Modules were primarily identified by nonnegative matrix factorization, and fewer modules correlated with poor walking performance on biomechanical and clinical measures. Fewer modules indicated reduced ability to control individual muscle timing during paretic leg stance. There was evidence that rehabilitation can lead to the use of more and/or better-timed modules. While future work will need to establish the ability of modules to identify impairment mechanisms, they appear to offer a promising analytical approach for evaluating motor control.
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29
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Profeta VL, Turvey MT. Bernstein’s levels of movement construction: A contemporary perspective. Hum Mov Sci 2018; 57:111-133. [DOI: 10.1016/j.humov.2017.11.013] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 11/24/2017] [Accepted: 11/27/2017] [Indexed: 01/13/2023]
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30
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Rimini D, Agostini V, Knaflitz M. Intra-Subject Consistency during Locomotion: Similarity in Shared and Subject-Specific Muscle Synergies. Front Hum Neurosci 2017; 11:586. [PMID: 29255410 PMCID: PMC5723022 DOI: 10.3389/fnhum.2017.00586] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 11/20/2017] [Indexed: 01/08/2023] Open
Abstract
Human locomotion is a complex motor task. Previous research hypothesized that muscle synergies reflect the modular control of muscle groups operated by the Central Nervous System (CNS). Despite the high stride-to-stride variability characterizing human gait, most studies analyze only a few strides. This may be limiting, because the intra-subject variability of motor output is neglected. This gap could be filled by recording and analyzing many gait cycles during a single walking task. In this way, it can be investigated if CNS recruits the same muscle synergies consistently or if different strategies are adopted during the locomotion task. The aim of this work is to investigate the intra-subject consistency of muscle synergies during overground walking. Twelve young healthy volunteers were instructed to walk for 5 min at their natural pace. On the average, 181 ± 10 gait cycles were analyzed for each subject. Surface electromyography was recorded from 12 muscles of the dominant lower limb and the trunk. Gait cycles were grouped into subgroups containing 10 gait cycles each. The consistency of the muscle synergies extracted during the gait trial was assessed by measuring cosine similarity (CS) of muscle weights vectors, and zero-lag cross-correlation (CC) of activation signals. The average intra-subject CS and CC were 0.94 ± 0.10 and 0.96 ± 0.06, respectively. We found five synergies shared by all the subjects: high consistency values were found for these synergies (CS = 0.96 ± 0.05, CC = 0.97 ± 0.03). In addition, we found 10 subject-specific synergies. These synergies were less consistent (CS = 0.80 ± 0.20, CC = 0.89 ± 0.14). In conclusion, our results demonstrated that shared muscle synergies were highly consistent during walking. Subject-specific muscle synergies were also consistent, although to a lesser extent.
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Affiliation(s)
- Daniele Rimini
- Dipartimento di Elettronica e Telecomunicazioni, Politecnico di Torino, Turin, Italy
| | - Valentina Agostini
- Dipartimento di Elettronica e Telecomunicazioni, Politecnico di Torino, Turin, Italy
| | - Marco Knaflitz
- Dipartimento di Elettronica e Telecomunicazioni, Politecnico di Torino, Turin, Italy
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31
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Rozumalski A, Steele KM, Schwartz MH. Muscle synergies are similar when typically developing children walk on a treadmill at different speeds and slopes. J Biomech 2017; 64:112-119. [PMID: 28943157 DOI: 10.1016/j.jbiomech.2017.09.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 06/23/2017] [Accepted: 09/04/2017] [Indexed: 11/16/2022]
Abstract
BACKGROUND The aim of this study was to determine whether changes in synergies relate to changes in gait while walking on a treadmill at multiple speeds and slopes. The hypothesis was that significant changes in movement pattern would not be accompanied by significant changes in synergies, suggesting that synergies are not dependent on the mechanical constraints but are instead neurological in origin. METHODS Sixteen typically developing children walked on a treadmill for nine combinations (stages) of different speeds and slopes while simultaneously collecting kinematics, kinetics, and surface electromyography (EMG) data. The kinematics for each stride were summarized using a modified version of the Gait Deviation Index that only includes the sagittal plane. The kinetics for each stride were summarized using a modified version of the Gait Deviation Index - Kinetic which includes sagittal plane moments and powers. Within each synergy group, the correlations of the synergies were calculated between the treadmill stages. RESULTS While kinematics and kinetics were significantly altered at the highest slope compared to level ground when walking on a treadmill, synergies were similar across stages. CONCLUSIONS The high correlations between synergies across stages indicate that neuromuscular control strategies do not change as children walk at different speeds and slopes on a treadmill. However, the multiple significant differences in kinematics and kinetics between stages indicate real differences in movement pattern. This supports the theory that synergies are neurological in origin and not simply a response to the biomechanical task constraints.
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Affiliation(s)
- Adam Rozumalski
- Gillette Children's Specialty Healthcare, St. Paul, MN, United States.
| | | | - Michael H Schwartz
- Gillette Children's Specialty Healthcare, St. Paul, MN, United States; University of Minnesota, Minneapolis, MN, United States
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32
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Barroso FO, Torricelli D, Molina-Rueda F, Alguacil-Diego IM, Cano-de-la-Cuerda R, Santos C, Moreno JC, Miangolarra-Page JC, Pons JL. Combining muscle synergies and biomechanical analysis to assess gait in stroke patients. J Biomech 2017; 63:98-103. [PMID: 28882330 DOI: 10.1016/j.jbiomech.2017.08.006] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2016] [Revised: 08/01/2017] [Accepted: 08/05/2017] [Indexed: 12/17/2022]
Abstract
The understanding of biomechanical deficits and impaired neural control of gait after stroke is crucial to prescribe effective customized treatments aimed at improving walking function. Instrumented gait analysis has been increasingly integrated into the clinical practice to enhance precision and inter-rater reliability for the assessment of pathological gait. On the other hand, the analysis of muscle synergies has gained relevance as a novel tool to describe the neural control of walking. Since muscle synergies and gait analysis capture different but equally important aspects of walking, we hypothesized that their combination can improve the current clinical tools for the assessment of walking performance. To test this hypothesis, we performed a complete bilateral, lower limb biomechanical and muscle synergies analysis on nine poststroke hemiparetic patients during overground walking. Using stepwise multiple regression, we identified a number of kinematic, kinetic, spatiotemporal and synergy-related features from the paretic and non-paretic side that, combined together, allow to predict impaired walking function better than the Fugl-Meyer Assessment score. These variables were time of peak knee flexion, VAFtotal values, duration of stance phase, peak of paretic propulsion and range of hip flexion. Since these five variables describe important biomechanical and neural control features underlying walking deficits poststroke, they may be feasible to drive customized rehabilitation therapies aimed to improve walking function. This paper demonstrates the feasibility of combining biomechanical and neural-related measures to assess locomotion performance in neurologically injured individuals.
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Affiliation(s)
- Filipe O Barroso
- Department of Physiology, Feinberg School of Medicine - Northwestern University, Chicago, IL, United States; Neural Rehabilitation Group, Cajal Institute, Spanish National Research Council (CSIC), Madrid, Spain; Centre ALGORITMI, University of Minho, Azurém, Guimarães, Portugal
| | - Diego Torricelli
- Neural Rehabilitation Group, Cajal Institute, Spanish National Research Council (CSIC), Madrid, Spain.
| | - Francisco Molina-Rueda
- Movement Analysis, Biomechanics, Ergonomic and Motor Control Laboratory (LAMBECOM), Faculty of Health Sciences at the Rey Juan Carlos University, Madrid, Spain
| | - Isabel M Alguacil-Diego
- Movement Analysis, Biomechanics, Ergonomic and Motor Control Laboratory (LAMBECOM), Faculty of Health Sciences at the Rey Juan Carlos University, Madrid, Spain
| | - Roberto Cano-de-la-Cuerda
- Movement Analysis, Biomechanics, Ergonomic and Motor Control Laboratory (LAMBECOM), Faculty of Health Sciences at the Rey Juan Carlos University, Madrid, Spain
| | - Cristina Santos
- Centre ALGORITMI, University of Minho, Azurém, Guimarães, Portugal
| | - Juan C Moreno
- Neural Rehabilitation Group, Cajal Institute, Spanish National Research Council (CSIC), Madrid, Spain
| | - Juan C Miangolarra-Page
- Movement Analysis, Biomechanics, Ergonomic and Motor Control Laboratory (LAMBECOM), Faculty of Health Sciences at the Rey Juan Carlos University, Madrid, Spain
| | - José L Pons
- Neural Rehabilitation Group, Cajal Institute, Spanish National Research Council (CSIC), Madrid, Spain
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33
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Shuman BR, Schwartz MH, Steele KM. Electromyography Data Processing Impacts Muscle Synergies during Gait for Unimpaired Children and Children with Cerebral Palsy. Front Comput Neurosci 2017. [PMID: 28634449 PMCID: PMC5460588 DOI: 10.3389/fncom.2017.00050] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Muscle synergies calculated from electromyography (EMG) data identify weighted groups of muscles activated together during functional tasks. Research has shown that fewer synergies are required to describe EMG data of individuals with neurologic impairments. When considering potential clinical applications of synergies, understanding how EMG data processing impacts results and clinical interpretation is important. The aim of this study was to evaluate how EMG signal processing impacts synergy outputs during gait. We evaluated the impacts of two common processing steps for synergy analyses: low pass (LP) filtering and unit variance scaling. We evaluated EMG data collected during barefoot walking from five muscles of 113 children with cerebral palsy (CP) and 73 typically-developing (TD) children. We applied LP filters to the EMG data with cutoff frequencies ranging from 4 to 40 Hz (reflecting the range reported in prior synergy research). We also evaluated the impact of normalizing EMG amplitude by unit variance. We found that the total variance accounted for (tVAF) by a given number of synergies was sensitive to LP filter choice and decreased in both TD and CP groups with increasing LP cutoff frequency (e.g., 9.3 percentage points change for one synergy between 4 and 40 Hz). This change in tVAF can alter the number of synergies selected for further analyses. Normalizing tVAF to a z-score (e.g., dynamic motor control index during walking, walk-DMC) reduced sensitivity to LP cutoff. Unit variance scaling caused comparatively small changes in tVAF. Synergy weights and activations were impacted less than tVAF by LP filter choice and unit variance normalization. These results demonstrate that EMG signal processing methods impact outputs of synergy analysis and z-score based measures can assist in reporting and comparing results across studies and clinical centers.
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Affiliation(s)
- Benjamin R Shuman
- Department of Mechanical Engineering, University of WashingtonSeattle, WA, United States.,WRF Institute for Neuroengineering, University of WashingtonSeattle, WA, United States
| | - Michael H Schwartz
- James R. Gage Center for Gait and Motion Analysis, Gillette Children's Specialty HealthcareSt. Paul, MN, United States.,Department of Biomedical Engineering, University of MinnesotaMinneapolis, MN, United States
| | - Katherine M Steele
- Department of Mechanical Engineering, University of WashingtonSeattle, WA, United States.,WRF Institute for Neuroengineering, University of WashingtonSeattle, WA, United States
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34
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Chia Bejarano N, Pedrocchi A, Nardone A, Schieppati M, Baccinelli W, Monticone M, Ferrigno G, Ferrante S. Tuning of Muscle Synergies During Walking Along Rectilinear and Curvilinear Trajectories in Humans. Ann Biomed Eng 2017; 45:1204-1218. [PMID: 28144794 DOI: 10.1007/s10439-017-1802-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 01/25/2017] [Indexed: 01/02/2023]
Abstract
The aim of this study was to develop a methodology based on muscle synergies to investigate whether rectilinear and curvilinear walking shared the same neuro-motor organization, and how this organization was fine-tuned by the walking condition. Thirteen healthy subjects walked on rectilinear and curvilinear paths. Electromyographic data from thirteen back and lower-limb muscles were acquired, together with kinematic data using inertial sensors. Four macroscopically invariant muscle synergies, extracted through non-negative matrix factorization, proved a shared modular organization across conditions. The fine-tuning of muscle synergies was studied through non-negative matrix reconstruction, applied by fixing muscle weights or activation profiles to those of the rectilinear condition. The activation profiles tended to be recruited for a longer period and with a larger amplitude during curvilinear walking. The muscles of the posterior side of the lower limb were those mainly influenced by the fine-tuning, with the muscles inside the rotation path being more active than the outer muscles. This study shows that rectilinear and curvilinear walking share a unique motor command. However, a fine-tuning in muscle synergies is introduced during curvilinear conditions, adapting the kinematic strategy to the new biomechanical needs.
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Affiliation(s)
- Noelia Chia Bejarano
- Neuroengineering and Medical Robotics Laboratory, Department of Electronics, Information and Bioengineering, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133, Milan, Italy.
| | - Alessandra Pedrocchi
- Neuroengineering and Medical Robotics Laboratory, Department of Electronics, Information and Bioengineering, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133, Milan, Italy
| | - Antonio Nardone
- Posture and Movement Laboratory, Division of Physical Medicine and Rehabilitation, Scientific Institute of Veruno, Fondazione Salvatore Maugeri (IRCCS), Veruno, Novara, Italy.,Department of Translational Medicine, University of Eastern Piedmont, Novara, Italy
| | - Marco Schieppati
- Department of Public Health, Experimental and Forensic Medicine, University of Pavia, Pavia, Italy.,Centro Studi Attività Motorie (CSAM), Scientific Institute of Pavia, Fondazione Salvatore Maugeri (IRCCS), Pavia, Italy
| | - Walter Baccinelli
- Neuroengineering and Medical Robotics Laboratory, Department of Electronics, Information and Bioengineering, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133, Milan, Italy.,Ab.Acus, Milan, Italy
| | - Marco Monticone
- Department of Public Health, Clinical and Molecular Medicine, University of Cagliari, Cagliari, Italy.,Physical Medicine and Rehabilitation Unit, Scientific Institute of Lissone, Fondazione Salvatore Maugeri (IRCCS), Lissone, Monza Brianza, Italy
| | - Giancarlo Ferrigno
- Neuroengineering and Medical Robotics Laboratory, Department of Electronics, Information and Bioengineering, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133, Milan, Italy
| | - Simona Ferrante
- Neuroengineering and Medical Robotics Laboratory, Department of Electronics, Information and Bioengineering, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133, Milan, Italy
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Lencioni T, Jonsdottir J, Cattaneo D, Crippa A, Gervasoni E, Rovaris M, Bizzi E, Ferrarin M. Are Modular Activations Altered in Lower Limb Muscles of Persons with Multiple Sclerosis during Walking? Evidence from Muscle Synergies and Biomechanical Analysis. Front Hum Neurosci 2016; 10:620. [PMID: 28018193 PMCID: PMC5145858 DOI: 10.3389/fnhum.2016.00620] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 11/21/2016] [Indexed: 12/21/2022] Open
Abstract
Background: Persons with Multiple Sclerosis frequently have gait deficits that lead to diminished activities of daily living. Identification of motoneuron activity patterns may elucidate new insight into impaired locomotor coordination and underlying neural systems. The aim of the present study was to investigate muscle synergies, identified by motor modules and their activation profiles, in persons with Multiple Sclerosis (PwMS) during walking compared to those of healthy subjects (HS), as well as, exploring relationship of muscle synergies with walking ability of PwMS. Methods: Seventeen PwMS walked at their natural speed while 12 HS walked at slower than their natural speeds in order to provide normative gait values at matched speeds (spatio-temporal, kinematic, and kinetic parameters and electromyography signals). Non-negative matrix factorization was used to identify muscle synergies from eight muscles. Pearson's correlation coefficient was used to evaluate the similarity of motor modules between PwMS and HS. To assess differences in module activations, each module's activation timing was integrated over 100% of gait cycle and the activation percentage was computed in six phases. Results: Fifty-nine% of PwMS and 58% of HS had 4 modules while the remaining of both populations had 3 modules. Module 2 (related to soleus, medial, and lateral gastrocnemius primarily involved in mid and terminal stance) and Module 3 (related to tibialis anterior and rectus femoris primarily involved in early stance, and early and late swing) were comparable across all subjects regardless of synergies number. PwMS had shorter stride length, longer double support phase and push off deficit with respect to HS (p < 0.05). The alterations of activation timing profiles of specific modules in PwMS were associated with their walking deficits (e.g., the reduction of Module 2 activation percentage index in terminal stance, PwMS 35.55 ± 13.23 vs. HS 50.51 ± 9.13% p < 0.05, and the push off deficit, PwMS 0.181 ± 0.136 vs. HS 0.291 ± 0.062 w/kg p < 0.05). Conclusion: During gait PwMS have synergies numbers similar to healthy persons. Their neurological deficit alters modular control through modifications of the timing activation profiles rather than module composition. These changes were associated with their main walking impairment, muscle weakness, and prolonged double support.
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Affiliation(s)
- Tiziana Lencioni
- Biomedical Technology Department, IRCCS Fondazione Don Carlo Gnocchi Onlus Milan, Italy
| | - Johanna Jonsdottir
- Department of Neurorehabilitation, IRCCS Fondazione Don Carlo Gnocchi Onlus, LaRiCE Milan, Italy
| | - Davide Cattaneo
- Department of Neurorehabilitation, IRCCS Fondazione Don Carlo Gnocchi Onlus, LaRiCE Milan, Italy
| | - Alessandro Crippa
- Department of Neurorehabilitation, IRCCS Fondazione Don Carlo Gnocchi Onlus, LaRiCE Milan, Italy
| | - Elisa Gervasoni
- Department of Neurorehabilitation, IRCCS Fondazione Don Carlo Gnocchi Onlus, LaRiCE Milan, Italy
| | - Marco Rovaris
- Department of Multiple Sclerosis, IRCCS Fondazione Don Carlo Gnocchi Onlus Milan, Italy
| | - Emilio Bizzi
- Department of Brain and Cognitive Sciences and McGovern Institute for Brain Research, Massachusetts Institute of Technology Cambridge, MA, USA
| | - Maurizio Ferrarin
- Biomedical Technology Department, IRCCS Fondazione Don Carlo Gnocchi Onlus Milan, Italy
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Ferrante S, Chia Bejarano N, Ambrosini E, Nardone A, Turcato AM, Monticone M, Ferrigno G, Pedrocchi A. A Personalized Multi-Channel FES Controller Based on Muscle Synergies to Support Gait Rehabilitation after Stroke. Front Neurosci 2016; 10:425. [PMID: 27695397 PMCID: PMC5025903 DOI: 10.3389/fnins.2016.00425] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 08/30/2016] [Indexed: 01/22/2023] Open
Abstract
It has been largely suggested in neuroscience literature that to generate a vast variety of movements, the Central Nervous System (CNS) recruits a reduced set of coordinated patterns of muscle activities, defined as muscle synergies. Recent neurophysiological studies have recommended the analysis of muscle synergies to finely assess the patient's impairment, to design personalized interventions based on the specific nature of the impairment, and to evaluate the treatment outcomes. In this scope, the aim of this study was to design a personalized multi-channel functional electrical stimulation (FES) controller for gait training, integrating three novel aspects: (1) the FES strategy was based on healthy muscle synergies in order to mimic the neural solutions adopted by the CNS to generate locomotion; (2) the FES strategy was personalized according to an initial locomotion assessment of the patient and was designed to specifically activate the impaired biomechanical functions; (3) the FES strategy was mapped accurately on the altered gait kinematics providing a maximal synchronization between patient's volitional gait and stimulation patterns. The novel intervention was tested on two chronic stroke patients. They underwent a 4-week intervention consisting of 30-min sessions of FES-supported treadmill walking three times per week. The two patients were characterized by a mild gait disability (walking speed > 0.8 m/s) at baseline. However, before treatment both patients presented only three independent muscle synergies during locomotion, resembling two different gait abnormalities. After treatment, the number of extracted synergies became four and they increased their resemblance with the physiological muscle synergies, which indicated a general improvement in muscle coordination. The originally merged synergies seemed to regain their distinct role in locomotion control. The treatment benefits were more evident for one patient, who achieved a clinically important change in dynamic balance (Mini-Best Test increased from 17 to 22) coupled with a very positive perceived treatment effect (GRC = 4). The treatment had started the neuro-motor relearning process also on the second subject, but twelve sessions were not enough to achieve clinically relevant improvements. This attempt to apply the novel theories of neuroscience research in stroke rehabilitation has provided promising results, and deserves to be further investigated in a larger clinical study.
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Affiliation(s)
- Simona Ferrante
- Neuroengineering and Medical Robotics Laboratory, Department of Electronics, Information and Bioengineering, Politecnico di Milano Milan, Italy
| | - Noelia Chia Bejarano
- Neuroengineering and Medical Robotics Laboratory, Department of Electronics, Information and Bioengineering, Politecnico di Milano Milan, Italy
| | - Emilia Ambrosini
- Neuroengineering and Medical Robotics Laboratory, Department of Electronics, Information and Bioengineering, Politecnico di MilanoMilan, Italy; Physical Medicine and Rehabilitation Unit, Scientific Institute of Lissone, Fondazione Salvatore Maugeri (IRCCS)Lissone, Monza Brianza, Italy
| | - Antonio Nardone
- Posture and Movement Laboratory, Division of Physical Medicine and Rehabilitation, Scientific Institute of Veruno, Fondazione Salvatore Maugeri (IRCCS)Veruno, Novara, Italy; Department of Translational Medicine, University of Eastern PiedmontNovara, Italy
| | - Anna M Turcato
- Posture and Movement Laboratory, Division of Physical Medicine and Rehabilitation, Scientific Institute of Veruno, Fondazione Salvatore Maugeri (IRCCS)Veruno, Novara, Italy; Department of Translational Medicine, University of Eastern PiedmontNovara, Italy
| | - Marco Monticone
- Physical Medicine and Rehabilitation Unit, Scientific Institute of Lissone, Fondazione Salvatore Maugeri (IRCCS)Lissone, Monza Brianza, Italy; Department of Public Health, Clinical and Molecular Medicine, University of CagliariCagliari, Italy
| | - Giancarlo Ferrigno
- Neuroengineering and Medical Robotics Laboratory, Department of Electronics, Information and Bioengineering, Politecnico di Milano Milan, Italy
| | - Alessandra Pedrocchi
- Neuroengineering and Medical Robotics Laboratory, Department of Electronics, Information and Bioengineering, Politecnico di Milano Milan, Italy
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Serrancolí G, Kinney AL, Fregly BJ, Font-Llagunes JM. Neuromusculoskeletal Model Calibration Significantly Affects Predicted Knee Contact Forces for Walking. J Biomech Eng 2016; 138:2525707. [PMID: 27210105 PMCID: PMC4913205 DOI: 10.1115/1.4033673] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Revised: 05/10/2016] [Indexed: 01/01/2023]
Abstract
Though walking impairments are prevalent in society, clinical treatments are often ineffective at restoring lost function. For this reason, researchers have begun to explore the use of patient-specific computational walking models to develop more effective treatments. However, the accuracy with which models can predict internal body forces in muscles and across joints depends on how well relevant model parameter values can be calibrated for the patient. This study investigated how knowledge of internal knee contact forces affects calibration of neuromusculoskeletal model parameter values and subsequent prediction of internal knee contact and leg muscle forces during walking. Model calibration was performed using a novel two-level optimization procedure applied to six normal walking trials from the Fourth Grand Challenge Competition to Predict In Vivo Knee Loads. The outer-level optimization adjusted time-invariant model parameter values to minimize passive muscle forces, reserve actuator moments, and model parameter value changes with (Approach A) and without (Approach B) tracking of experimental knee contact forces. Using the current guess for model parameter values but no knee contact force information, the inner-level optimization predicted time-varying muscle activations that were close to experimental muscle synergy patterns and consistent with the experimental inverse dynamic loads (both approaches). For all the six gait trials, Approach A predicted knee contact forces with high accuracy for both compartments (average correlation coefficient r = 0.99 and root mean square error (RMSE) = 52.6 N medial; average r = 0.95 and RMSE = 56.6 N lateral). In contrast, Approach B overpredicted contact force magnitude for both compartments (average RMSE = 323 N medial and 348 N lateral) and poorly matched contact force shape for the lateral compartment (average r = 0.90 medial and -0.10 lateral). Approach B had statistically higher lateral muscle forces and lateral optimal muscle fiber lengths but lower medial, central, and lateral normalized muscle fiber lengths compared to Approach A. These findings suggest that poorly calibrated model parameter values may be a major factor limiting the ability of neuromusculoskeletal models to predict knee contact and leg muscle forces accurately for walking.
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Affiliation(s)
- Gil Serrancolí
- Department of Mechanical Engineering and
Biomedical Engineering Research Centre,
Universitat Politècnica de Catalunya,
Barcelona, Catalunya 08028, Spain
e-mail:
| | - Allison L. Kinney
- Department of Mechanical and
Aerospace Engineering,
University of Dayton,
Dayton, OH 45469
e-mail:
| | - Benjamin J. Fregly
- Department of Mechanical and
Aerospace Engineering,
University of Florida,
Gainesville, FL 32611
e-mail:
| | - Josep M. Font-Llagunes
- Department of Mechanical Engineering and
Biomedical Engineering Research Centre,
Universitat Politècnica de Catalunya,
Av. Diagonal 647,
Barcelona, Catalunya 08028, Spain
e-mail:
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38
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Pérez-Nombela S, Barroso F, Torricelli D, de Los Reyes-Guzmán A, Del-Ama AJ, Gómez-Soriano J, Pons JL, Gil-Agudo Á. Modular control of gait after incomplete spinal cord injury: differences between sides. Spinal Cord 2016; 55:79-86. [PMID: 27349606 DOI: 10.1038/sc.2016.99] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 03/21/2016] [Accepted: 05/24/2016] [Indexed: 01/11/2023]
Abstract
STUDY DESIGN This is an analytical descriptive study. OBJECTIVES The main goal of this study was to compare the modular organization of bilateral lower limb control in incomplete spinal cord injury (iSCI) patients during overground walking, using muscle synergies analysis. The secondary goal was to determine whether the similarity between the patients and control group correlate with clinical indicators of walking performance. SETTING This study was conducted in National Hospital for Spinal Cord Injury (Toledo, Spain). METHODS Eight iSCI patients and eight healthy subjects completed 10 walking trials at matched speed. For each trial, three-dimensional motion analysis and surface electromyography (sEMG) analysis of seven leg muscles from both limbs were performed. Muscle synergies were extracted from sEMG signals using a non-negative matrix factorization algorithm. The optimal number of synergies has been defined as the minimum number needed to obtain variability accounted for (VAF) ⩾90%. RESULTS When compared with healthy references, iSCI patients showed fewer muscle synergies in the most affected side and, in both sides, significant differences in the composition of synergy 2. The degree of similarity of these variables with the healthy reference, together with the composition of synergy 3 of the most affected side, presented significant correlations (P<0.05) with walking performance. CONCLUSION The analysis of muscle synergies shows potential to detect differences between the two sides in patients with iSCI. Specifically, the VAF may constitute a new neurophysiological metric to assess and monitor patients' condition throughout the gait recovery process.
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Affiliation(s)
- S Pérez-Nombela
- Biomechanical and Technical Aids Department, National Hospital for Spinal Cord Injury, Toledo, Spain
| | - F Barroso
- Neural Rehabilitation Group, Cajal Institute, Spanish National Research Council (CSIC), Madrid, Spain.,Centre ALGORITMI, University of Minho, Azurém, Guimarães, Portugal
| | - D Torricelli
- Neural Rehabilitation Group, Cajal Institute, Spanish National Research Council (CSIC), Madrid, Spain
| | - A de Los Reyes-Guzmán
- Biomechanical and Technical Aids Department, National Hospital for Spinal Cord Injury, Toledo, Spain
| | - A J Del-Ama
- Biomechanical and Technical Aids Department, National Hospital for Spinal Cord Injury, Toledo, Spain
| | - J Gómez-Soriano
- Sensoriomotor Function Group, National Hospital for Spinal Cord Injury, Toledo, Spain.,Toledo Physiotherapy Research Group (GIFTO). Nursing and Physical Therapy School, Castilla-La Mancha, Toledo, Spain
| | - J L Pons
- Neural Rehabilitation Group, Cajal Institute, Spanish National Research Council (CSIC), Madrid, Spain
| | - Á Gil-Agudo
- Biomechanical and Technical Aids Department, National Hospital for Spinal Cord Injury, Toledo, Spain
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39
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Shuman B, Goudriaan M, Bar-On L, Schwartz MH, Desloovere K, Steele KM. Repeatability of muscle synergies within and between days for typically developing children and children with cerebral palsy. Gait Posture 2016; 45:127-32. [PMID: 26979894 DOI: 10.1016/j.gaitpost.2016.01.011] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Muscle synergies are typically calculated from electromyographic (EMG) signals using nonnegative matrix factorization. Synergies identify weighted groups of muscles that are commonly activated together during a task, such as walking. Synergy analysis has become an emerging tool to evaluate neuromuscular control; however, the repeatability of synergies between trials and days has not been evaluated. The goal of this study was to evaluate the repeatability of synergy complexity and structure in unimpaired individuals and individuals with cerebral palsy (CP). EMG data were collected from eight lower-limb muscles during gait for six typically developing (TD) children and five children with CP on two separate days, over three walking speeds. To evaluate synergy complexity, we calculated the total variance accounted for by one synergy (tVAF1). On a given day, the average range in tVAF1 between gait cycles was 18.2% for TD and 19.1% for CP. The average standard deviation in tVAF1 between gait cycles was 4.9% for TD and 5.0% for CP. Average tVAF1 calculated across gait cycles was not significantly different between days for TD or CP participants. Comparing synergy structure, the average (standard deviation) within day correlation coefficients of synergy weights for two or more synergies were 0.89 (0.15) for TD and 0.88 (0.15) for CP. Between days, the average correlation coefficient of synergy weights for two or more synergies was greater than 0.89 for TD and 0.74 for CP. These results demonstrate that synergy complexity and structure averaged over multiple gait cycles are repeatable between days in both TD and CP groups.
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Affiliation(s)
- Benjamin Shuman
- University of Washington, Department of Mechanical Engineering, Seattle, WA 98195, USA
| | - Marije Goudriaan
- KU Leuven, Department of Rehabilitation Science, University of Leuven, Leuven, Belgium
| | - Lynn Bar-On
- KU Leuven, Department of Rehabilitation Science, University of Leuven, Leuven, Belgium
| | - Michael H Schwartz
- James R. Gage Center for Gait & Motion Analysis, Gillette Children's Specialty Healthcare, St. Paul, MN 55101, USA; University of Minnesota, Department of Biomedical Engineering, Minneapolis, MN, USA
| | - Kaat Desloovere
- KU Leuven, Department of Rehabilitation Science, University of Leuven, Leuven, Belgium
| | - Katherine M Steele
- University of Washington, Department of Mechanical Engineering, Seattle, WA 98195, USA.
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40
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Balasubramanian CK, Li CY, Bowden MG, Duncan PW, Kautz SA, Velozo CA. Dimensionality and Item-Difficulty Hierarchy of the Lower Extremity Fugl-Meyer Assessment in Individuals With Subacute and Chronic Stroke. Arch Phys Med Rehabil 2015; 97:582-589.e2. [PMID: 26740065 DOI: 10.1016/j.apmr.2015.12.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 12/05/2015] [Accepted: 12/07/2015] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To investigate the dimensionality and item-difficulty hierarchy of the Fugl-Meyer Assessment of the lower extremity (FMA-LE). DESIGN Secondary analyses of data pooled from 4 existing datasets: a phase III randomized controlled trial investigating the effectiveness of body weight support and a treadmill for rehabilitation of walking poststroke, and 3 cross-sectional studies investigating the link between impaired motor performance poststroke and walking. SETTING University research centers and rehabilitation centers. PARTICIPANTS A pooled sample of individuals with a stroke (N=535, men=313; mean age ± SD, 61.91±12.42y). INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Confirmatory factor analyses (CFA) and Rasch residual principal component analysis (PCA) investigated the dimensionality of the FMA-LE. The Rasch analysis rating scale model investigated item-difficulty hierarchy of the FMA-LE. RESULTS The CFA showed adequate fit of a 3-factor model, with 2 out of 3 indices (CFA=.95; Tucker-Lewis Index=.94; root mean square error of approximation=.124) showing good model fit. Rasch PCA showed that removal of the reflex and coordination items explained 90.8% of variance in the data, suggesting that the abnormal synergy items contributed to the measurement of a unidimensional construct. However, rating scale model results revealed deviations in the item-difficulty hierarchy of the unidimensional abnormal synergy items from the originally proposed stepwise sequence of motor recovery. CONCLUSIONS Our findings suggest that the FMA-LE might represent a multidimensional construct, challenging the use of a total score of the FMA-LE to predict lower extremity motor recovery. Removal of the misfit items resulted in creation of a unidimensional scale composed of the abnormal synergy items. However, this unidimensional scale deviates from the originally proposed hierarchical ordering.
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Affiliation(s)
| | - Chih-Ying Li
- Department of Health Science and Research and Division of Physical Therapy, College of Health Profession, Medical University of South Carolina, Charleston, SC
| | - Mark G Bowden
- Department of Health Science and Research and Division of Physical Therapy, College of Health Profession, Medical University of South Carolina, Charleston, SC; Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC
| | - Pamela W Duncan
- Department of Neurology, Wake Forest University, Winston-Salem, NC
| | - Steven A Kautz
- Department of Health Science and Research and Division of Physical Therapy, College of Health Profession, Medical University of South Carolina, Charleston, SC; Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC
| | - Craig A Velozo
- Division of Occupational Therapy, College of Health Profession, Medical University of South Carolina, Charleston, SC
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41
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Beyaert C, Vasa R, Frykberg GE. Gait post-stroke: Pathophysiology and rehabilitation strategies. Neurophysiol Clin 2015; 45:335-55. [PMID: 26547547 DOI: 10.1016/j.neucli.2015.09.005] [Citation(s) in RCA: 163] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 09/14/2015] [Accepted: 09/22/2015] [Indexed: 12/16/2022] Open
Abstract
We reviewed neural control and biomechanical description of gait in both non-disabled and post-stroke subjects. In addition, we reviewed most of the gait rehabilitation strategies currently in use or in development and observed their principles in relation to recent pathophysiology of post-stroke gait. In both non-disabled and post-stroke subjects, motor control is organized on a task-oriented basis using a common set of a few muscle modules to simultaneously achieve body support, balance control, and forward progression during gait. Hemiparesis following stroke is due to disruption of descending neural pathways, usually with no direct lesion of the brainstem and cerebellar structures involved in motor automatic processes. Post-stroke, improvements of motor activities including standing and locomotion are variable but are typically characterized by a common postural behaviour which involves the unaffected side more for body support and balance control, likely in response to initial muscle weakness of the affected side. Various rehabilitation strategies are regularly used or in development, targeting muscle activity, postural and gait tasks, using more or less high-technology equipment. Reduced walking speed often improves with time and with various rehabilitation strategies, but asymmetric postural behaviour during standing and walking is often reinforced, maintained, or only transitorily decreased. This asymmetric compensatory postural behaviour appears to be robust, driven by support and balance tasks maintaining the predominant use of the unaffected side over the initially impaired affected side. Based on these elements, stroke rehabilitation including affected muscle strengthening and often stretching would first need to correct the postural asymmetric pattern by exploiting postural automatic processes in various particular motor tasks secondarily beneficial to gait.
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Affiliation(s)
- C Beyaert
- EA3450, Université de Lorraine, Faculty of Medicine, 54500 Vandœuvre-lès-Nancy, France; Motion Analysis Laboratory, L.-Pierquin Rehabilitation Center, 54000 Nancy, France.
| | - R Vasa
- RV Foundation, Centre for Brain and Spinal Injury Rehab, Mumbai, India
| | - G E Frykberg
- Department of Neuroscience/Rehabilitation Medicine, Uppsala University, 75158 Uppsala, Sweden
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42
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Sawers A, Allen JL, Ting LH. Long-term training modifies the modular structure and organization of walking balance control. J Neurophysiol 2015; 114:3359-73. [PMID: 26467521 DOI: 10.1152/jn.00758.2015] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 10/13/2015] [Indexed: 01/08/2023] Open
Abstract
How does long-term training affect the neural control of movements? Here we tested the hypothesis that long-term training leading to skilled motor performance alters muscle coordination during challenging, as well as nominal everyday motor behaviors. Using motor module (a.k.a., muscle synergy) analyses, we identified differences in muscle coordination patterns between professionally trained ballet dancers (experts) and untrained novices that accompanied differences in walking balance proficiency assessed using a challenging beam-walking test. During beam walking, we found that experts recruited more motor modules than novices, suggesting an increase in motor repertoire size. Motor modules in experts had less muscle coactivity and were more consistent than in novices, reflecting greater efficiency in muscle output. Moreover, the pool of motor modules shared between beam and overground walking was larger in experts compared with novices, suggesting greater generalization of motor module function across multiple behaviors. These differences in motor output between experts and novices could not be explained by differences in kinematics, suggesting that they likely reflect differences in the neural control of movement following years of training rather than biomechanical constraints imposed by the activity or musculoskeletal structure and function. Our results suggest that to learn challenging new behaviors, we may take advantage of existing motor modules used for related behaviors and sculpt them to meet the demands of a new behavior.
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Affiliation(s)
- Andrew Sawers
- Department of Kinesiology, University of Illinois at Chicago, Chicago, Illinois; and
| | - Jessica L Allen
- Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, Georgia
| | - Lena H Ting
- Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, Georgia
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43
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Martino G, Ivanenko YP, d'Avella A, Serrao M, Ranavolo A, Draicchio F, Cappellini G, Casali C, Lacquaniti F. Neuromuscular adjustments of gait associated with unstable conditions. J Neurophysiol 2015; 114:2867-82. [PMID: 26378199 DOI: 10.1152/jn.00029.2015] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 09/11/2015] [Indexed: 12/20/2022] Open
Abstract
A compact description of coordinated muscle activity is provided by the factorization of electromyographic (EMG) signals. With the use of this approach, it has consistently been shown that multimuscle activity during human locomotion can be accounted for by four to five modules, each one comprised of a basic pattern timed at a different phase of gait cycle and the weighting coefficients of synergistic muscle activations. These modules are flexible, in so far as the timing of patterns and the amplitude of weightings can change as a function of gait speed and mode. Here we consider the adjustments of the locomotor modules related to unstable walking conditions. We compared three different conditions, i.e., locomotion of healthy subjects on slippery ground (SL) and on narrow beam (NB) and of cerebellar ataxic (CA) patients on normal ground. Motor modules were computed from the EMG signals of 12 muscles of the right lower limb using non-negative matrix factorization. The unstable gait of SL, NB, and CA showed significant changes compared with controls in the stride length, stride width, range of angular motion, and trunk oscillations. In most subjects of all three unstable conditions, >70% of the overall variation of EMG waveforms was accounted for by four modules that were characterized by a widening of muscle activity patterns. This suggests that the nervous system adopts the strategy of prolonging the duration of basic muscle activity patterns to cope with unstable conditions resulting from either slippery ground, reduced support surface, or pathology.
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Affiliation(s)
- G Martino
- Centre of Space Biomedicine, University of Rome Tor Vergata, Rome, Italy; Laboratory of Neuromotor Physiology, Istituto di Ricovero e Cura a Carattere Scientifico, Santa Lucia Foundation, Rome, Italy;
| | - Y P Ivanenko
- Laboratory of Neuromotor Physiology, Istituto di Ricovero e Cura a Carattere Scientifico, Santa Lucia Foundation, Rome, Italy
| | - A d'Avella
- Laboratory of Neuromotor Physiology, Istituto di Ricovero e Cura a Carattere Scientifico, Santa Lucia Foundation, Rome, Italy; Department of Biomedical Sciences and Morphological and Functional Images, University of Messina, Messina, Italy
| | - M Serrao
- Rehabilitation Centre Policlinico Italia, Rome, Italy; Department of Medical and Surgical Sciences and Biotechnologies, Sapienza University of Rome, Latina, Italy
| | - A Ranavolo
- Istituto Nazionale per l'Assicurazione Contro gli Infortuni sul Lavoro, Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Monte Porzio Catone, Rome, Italy; and
| | - F Draicchio
- Istituto Nazionale per l'Assicurazione Contro gli Infortuni sul Lavoro, Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Monte Porzio Catone, Rome, Italy; and
| | - G Cappellini
- Centre of Space Biomedicine, University of Rome Tor Vergata, Rome, Italy
| | - C Casali
- Department of Medical and Surgical Sciences and Biotechnologies, Sapienza University of Rome, Latina, Italy
| | - F Lacquaniti
- Centre of Space Biomedicine, University of Rome Tor Vergata, Rome, Italy; Laboratory of Neuromotor Physiology, Istituto di Ricovero e Cura a Carattere Scientifico, Santa Lucia Foundation, Rome, Italy; Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
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Sedaghat-Nejad E, Mousavi SJ, Hadizadeh M, Narimani R, Khalaf K, Campbell-Kyureghyan N, Parnianpour M. Is there a reliable and invariant set of muscle synergy during isometric biaxial trunk exertion in the sagittal and transverse planes by healthy subjects? J Biomech 2015; 48:3234-41. [DOI: 10.1016/j.jbiomech.2015.06.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 06/19/2015] [Accepted: 06/27/2015] [Indexed: 10/23/2022]
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Ting LH, Chiel HJ, Trumbower RD, Allen JL, McKay JL, Hackney ME, Kesar TM. Neuromechanical principles underlying movement modularity and their implications for rehabilitation. Neuron 2015; 86:38-54. [PMID: 25856485 DOI: 10.1016/j.neuron.2015.02.042] [Citation(s) in RCA: 246] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Neuromechanical principles define the properties and problems that shape neural solutions for movement. Although the theoretical and experimental evidence is debated, we present arguments for consistent structures in motor patterns, i.e., motor modules, that are neuromechanical solutions for movement particular to an individual and shaped by evolutionary, developmental, and learning processes. As a consequence, motor modules may be useful in assessing sensorimotor deficits specific to an individual and define targets for the rational development of novel rehabilitation therapies that enhance neural plasticity and sculpt motor recovery. We propose that motor module organization is disrupted and may be improved by therapy in spinal cord injury, stroke, and Parkinson's disease. Recent studies provide insights into the yet-unknown underlying neural mechanisms of motor modules, motor impairment, and motor learning and may lead to better understanding of the causal nature of modularity and its underlying neural substrates.
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Affiliation(s)
- Lena H Ting
- W.H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA 30332, USA; Department of Rehabilitation Medicine, Division of Physical Therapy, Emory University, Atlanta, GA 30322, USA.
| | - Hillel J Chiel
- Department of Biology, Case Western Reserve University, Cleveland, OH 44106, USA; Department of Neurosciences, Case Western Reserve University, Cleveland, OH 44106, USA; Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Randy D Trumbower
- W.H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA 30332, USA; Department of Rehabilitation Medicine, Division of Physical Therapy, Emory University, Atlanta, GA 30322, USA
| | - Jessica L Allen
- W.H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - J Lucas McKay
- W.H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Madeleine E Hackney
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta, GA 30033, USA; Department of Medicine, Division of General Medicine and Geriatrics, Emory University, Atlanta, GA 30322, USA
| | - Trisha M Kesar
- W.H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA 30332, USA; Department of Rehabilitation Medicine, Division of Physical Therapy, Emory University, Atlanta, GA 30322, USA
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