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Kaufmann P, Koller W, Wallnöfer E, Goncalves B, Baca A, Kainz H. Increased trial-to-trial similarity and reduced temporal overlap of muscle synergy activation coefficients manifest during learning and with increasing movement proficiency. Sci Rep 2024; 14:17638. [PMID: 39085397 PMCID: PMC11291506 DOI: 10.1038/s41598-024-68515-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 07/23/2024] [Indexed: 08/02/2024] Open
Abstract
Muscle synergy analyses are used to enhance our understanding of motor control. Spatially fixed synergy weights coordinate multiple co-active muscles through activation commands, known as activation coefficients. To gain a more comprehensive understanding of motor learning, it is essential to understand how activation coefficients vary during a learning task and at different levels of movement proficiency. Participants walked on a line, a beam, and learned to walk on a tightrope-tasks that represent different levels of proficiency. Muscle synergies were extracted from electromyography signals across all conditions and the number of synergies was determined by the knee-point of the total variance accounted for (tVAF) curve. The results indicated that the tVAF of one synergy decreased with task proficiency, with the tightrope task resulting in the highest tVAF compared to the line and beam tasks. Furthermore, with increasing proficiency and after a learning process, trial-to-trial similarity increased and temporal overlap of synergy activation coefficients decreased. Consequently, we propose that precise adjustment and refinement of synergy activation coefficients play a pivotal role in motor learning.
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Affiliation(s)
- Paul Kaufmann
- Department of Biomechanics, Kinesiology and Computer Science in Sport, Centre for Sport Science and University Sports, University of Vienna, Auf Der Schmelz 6a (USZ ||), 1150, Vienna, Austria
- Neuromechanics Research Group, Centre for Sport Science and University Sports, University of Vienna, Auf Der Schmelz 6a, 1150, Vienna, Austria
| | - Willi Koller
- Department of Biomechanics, Kinesiology and Computer Science in Sport, Centre for Sport Science and University Sports, University of Vienna, Auf Der Schmelz 6a (USZ ||), 1150, Vienna, Austria
- Neuromechanics Research Group, Centre for Sport Science and University Sports, University of Vienna, Auf Der Schmelz 6a, 1150, Vienna, Austria
| | - Elias Wallnöfer
- Department of Biomechanics, Kinesiology and Computer Science in Sport, Centre for Sport Science and University Sports, University of Vienna, Auf Der Schmelz 6a (USZ ||), 1150, Vienna, Austria
- Neuromechanics Research Group, Centre for Sport Science and University Sports, University of Vienna, Auf Der Schmelz 6a, 1150, Vienna, Austria
| | - Basilio Goncalves
- Department of Biomechanics, Kinesiology and Computer Science in Sport, Centre for Sport Science and University Sports, University of Vienna, Auf Der Schmelz 6a (USZ ||), 1150, Vienna, Austria
- Neuromechanics Research Group, Centre for Sport Science and University Sports, University of Vienna, Auf Der Schmelz 6a, 1150, Vienna, Austria
| | - Arnold Baca
- Department of Biomechanics, Kinesiology and Computer Science in Sport, Centre for Sport Science and University Sports, University of Vienna, Auf Der Schmelz 6a (USZ ||), 1150, Vienna, Austria
| | - Hans Kainz
- Department of Biomechanics, Kinesiology and Computer Science in Sport, Centre for Sport Science and University Sports, University of Vienna, Auf Der Schmelz 6a (USZ ||), 1150, Vienna, Austria.
- Neuromechanics Research Group, Centre for Sport Science and University Sports, University of Vienna, Auf Der Schmelz 6a, 1150, Vienna, Austria.
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2
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Morozumi T, Preziosa P, Meani A, Pessina G, Pagani E, Azzimonti M, Filippi M, Rocca MA. Brain and cervical spinal cord MRI correlates of sensorimotor impairment in patients with multiple sclerosis. Mult Scler 2024; 30:1004-1015. [PMID: 38912804 DOI: 10.1177/13524585241260145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/25/2024]
Abstract
BACKGROUND Cervical spinal cord (cSC) lesions and atrophy contribute to disability in multiple sclerosis (MS), but associations with specific sensorimotor dysfunction require further exploration. OBJECTIVE To investigate the associations of brain and cSC magnetic resonance imaging (MRI) measures with sensorimotor impairment in MS. METHODS One hundred fifty-one MS patients and 69 healthy controls underwent 3T MRI and clinical assessments including Expanded Disability Status Scale (EDSS), 9-hole peg test (9-HPT), finger tapping test (FTT), timed 25-foot walk test (T25FWT), and vibration detection threshold (VDT). Random forest ranked brain (T2-hyperintense lesion volume (T2-LV) and normalized deep gray matter (GM), cortical and white matter (WM) volumes) and cSC (T2-LV and total, GM, and WM cross-sectional areas (CSAs) at C2/C3 level) MRI measures relevance in explaining EDSS milestones (EDSS ⩾3.0, ⩾4.0, and ⩾6.0), VDT, pyramidal and sensory functional systems (P-FS and S-FS ⩾2), and motor tests impairment. RESULTS Various combinations of brain and cSC MRI measures explained EDSS milestones (area under the curve (AUC) =0.879-0.900), VDT (R2 = 0.194), and impaired P-FS (AUC = 0.820), S-FS (AUC = 0.795), 9-HPT (AUC = 0.793), FTT (AUC = 0.740), and T25FWT (AUC = 0.825). cSC GM CSA was the most informative feature for all outcomes, except 9-HPT. CONCLUSION cSC MRI measures, especially GM CSA, explain EDSS and sensorimotor dysfunction better than brain measures in MS.
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Affiliation(s)
- Tetsu Morozumi
- Neuroimaging Research Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Paolo Preziosa
- Neuroimaging Research Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Neurology Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy/Vita-Salute San Raffaele University, Milan, Italy
| | - Alessandro Meani
- Neuroimaging Research Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Giorgia Pessina
- Neuroimaging Research Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Elisabetta Pagani
- Neuroimaging Research Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Matteo Azzimonti
- Neuroimaging Research Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Neurology Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy/Vita-Salute San Raffaele University, Milan, Italy
| | - Massimo Filippi
- Neuroimaging Research Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Neurology Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Vita-Salute San Raffaele University, Milan, Italy
- Neurorehabilitation Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Neurophysiology Service, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Maria A Rocca
- Neuroimaging Research Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Neurology Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy/Vita-Salute San Raffaele University, Milan, Italy
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3
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Brüll L, Santuz A, Mersmann F, Bohm S, Schwenk M, Arampatzis A. Spatiotemporal modulation of a common set of muscle synergies during unpredictable and predictable gait perturbations in older adults. J Exp Biol 2024; 227:jeb247271. [PMID: 38506185 PMCID: PMC11058090 DOI: 10.1242/jeb.247271] [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: 01/03/2024] [Accepted: 03/14/2024] [Indexed: 03/21/2024]
Abstract
Muscle synergies as functional low-dimensional building blocks of the neuromotor system regulate the activation patterns of muscle groups in a modular structure during locomotion. The purpose of the current study was to explore how older adults organize locomotor muscle synergies to counteract unpredictable and predictable gait perturbations during the perturbed steps and the recovery steps. Sixty-three healthy older adults (71.2±5.2 years) participated in the study. Mediolateral and anteroposterior unpredictable and predictable perturbations during walking were introduced using a treadmill. Muscle synergies were extracted from the electromyographic activity of 13 lower limb muscles using Gaussian non-negative matrix factorization. The four basic synergies responsible for unperturbed walking (weight acceptance, propulsion, early swing and late swing) were preserved in all applied gait perturbations, yet their temporal recruitment and muscle contribution in each synergy were modified (P<0.05). These modifications were observed for up to four recovery steps and were more pronounced (P<0.05) following unpredictable perturbations. The recruitment of the four basic walking synergies in the perturbed and recovery gait cycles indicates a robust neuromotor control of locomotion by using activation patterns of a few and well-known muscle synergies with specific adjustments within the synergies. The selection of pre-existing muscle synergies while adjusting the time of their recruitment during challenging locomotor conditions may improve the effectiveness to deal with perturbations and promote the transfer of adaptation between different kinds of perturbations.
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Affiliation(s)
- Leon Brüll
- 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
- Network Aging Research, Heidelberg University, 69115 Heidelberg, Germany
| | - 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
| | - Falk Mersmann
- 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
| | - Sebastian Bohm
- 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
| | - Michael Schwenk
- Network Aging Research, Heidelberg University, 69115 Heidelberg, Germany
- Institute of Sports and Sports Sciences, Heidelberg University, 69120 Heidelberg, Germany
- Department of Sport Science, Human Performance Research Center, University of Konstanz, 78464 Konstanz, Germany
| | - 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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4
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Druelle F, Ghislieri M, Molina-Vila P, Rimbaud B, Agostini V, Berillon G. A comparative study of muscle activity and synergies during walking in baboons and humans. J Hum Evol 2024; 189:103513. [PMID: 38401300 DOI: 10.1016/j.jhevol.2024.103513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Revised: 02/15/2024] [Accepted: 02/16/2024] [Indexed: 02/26/2024]
Abstract
Bipedal locomotion was a major functional change during hominin evolution, yet, our understanding of this gradual and complex process remains strongly debated. Based on fossil discoveries, it is possible to address functional hypotheses related to bipedal anatomy, however, motor control remains intangible with this approach. Using comparative models which occasionally walk bipedally has proved to be relevant to shed light on the evolutionary transition toward habitual bipedalism. Here, we explored the organization of the neuromuscular control using surface electromyography (sEMG) for six extrinsic muscles in two baboon individuals when they walk quadrupedally and bipedally on the ground. We compared their muscular coordination to five human subjects walking bipedally. We extracted muscle synergies from the sEMG envelopes using the non-negative matrix factorization algorithm which allows decomposing the sEMG data in the linear combination of two non-negative matrixes (muscle weight vectors and activation coefficients). We calculated different parameters to estimate the complexity of the sEMG signals, the duration of the activation of the synergies, and the generalizability of the muscle synergy model across species and walking conditions. We found that the motor control strategy is less complex in baboons when they walk bipedally, with an increased muscular activity and muscle coactivation. When comparing the baboon bipedal and quadrupedal pattern of walking to human bipedalism, we observed that the baboon bipedal pattern of walking is closer to human bipedalism for both baboons, although substantial differences remain. Overall, our findings show that the muscle activity of a non-adapted biped effectively fulfills the basic mechanical requirements (propulsion and balance) for walking bipedally, but substantial refinements are possible to optimize the efficiency of bipedal locomotion. In the evolutionary context of an expanding reliance on bipedal behaviors, even minor morphological alterations, reducing muscle coactivation, could have faced strong selection pressure, ultimately driving bipedal evolution in hominins.
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Affiliation(s)
- François Druelle
- Histoire Naturelle de l'Homme Préhistorique, UMR 7194, CNRS-MNHN-UPVD, Musée de l'Homme, 17 place du Trocadéro, 75116 Paris, France; Primatology Station of the CNRS, UAR 846, 2230 route des quatre tours, 13790 Rousset, France; Functional Morphology Laboratory, University of Antwerp, Campus Drie Eiken (Building D), Universiteitsplein 1, 2610 Antwerp, Belgium.
| | - Marco Ghislieri
- Department of Electronics and Telecommunications, Politecnico di Torino, Corso Duca degli Abruzzi, 24, 10129 Turin, Italy; PoliTo(BIO)Med Lab, Politecnico di Torino, Corso Duca degli Abruzzi, 24, 10129 Turin, Italy
| | - Pablo Molina-Vila
- Primatology Station of the CNRS, UAR 846, 2230 route des quatre tours, 13790 Rousset, France
| | - Brigitte Rimbaud
- Primatology Station of the CNRS, UAR 846, 2230 route des quatre tours, 13790 Rousset, France
| | - Valentina Agostini
- Department of Electronics and Telecommunications, Politecnico di Torino, Corso Duca degli Abruzzi, 24, 10129 Turin, Italy; PoliTo(BIO)Med Lab, Politecnico di Torino, Corso Duca degli Abruzzi, 24, 10129 Turin, Italy
| | - Gilles Berillon
- Histoire Naturelle de l'Homme Préhistorique, UMR 7194, CNRS-MNHN-UPVD, Musée de l'Homme, 17 place du Trocadéro, 75116 Paris, France; Primatology Station of the CNRS, UAR 846, 2230 route des quatre tours, 13790 Rousset, France
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5
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Fazzari C, Macchi R, Kunimasa Y, Ressam C, Casanova R, Chavet P, Nicol C. Muscle synergies inherent in simulated hypogravity running reveal flexible but not unconstrained locomotor control. Sci Rep 2024; 14:2707. [PMID: 38302569 PMCID: PMC10834966 DOI: 10.1038/s41598-023-50076-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 12/15/2023] [Indexed: 02/03/2024] Open
Abstract
With human space exploration back in the spotlight, recent studies have investigated the neuromuscular adjustments to simulated hypogravity running. They have examined the activity of individual muscles, whereas the central nervous system may rather activate groups of functionally related muscles, known as muscle synergies. To understand how locomotor control adjusts to simulated hypogravity, we examined the temporal (motor primitives) and spatial (motor modules) components of muscle synergies in participants running sequentially at 100%, 60%, and 100% body weight on a treadmill. Our results highlighted the paradoxical nature of simulated hypogravity running: The reduced mechanical constraints allowed for a more flexible locomotor control, which correlated with the degree of spatiotemporal adjustments. Yet, the increased temporal (shortened stance phase) and sensory (deteriorated proprioceptive feedback) constraints required wider motor primitives and a higher contribution of the hamstring muscles during the stance phase. These results are a first step towards improving astronaut training protocols.
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Affiliation(s)
| | - Robin Macchi
- Aix-Marseille Univ, CNRS, ISM, Marseille, France
- French Institute of Sport (INSEP), Laboratory Sport, Expertise and Performance (EA 7370), Paris, France
| | | | - Camélia Ressam
- NeuroSpin, UMR CEA/CNRS 9027, Paris-Saclay University, Gif-sur-Yvette, France
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6
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Block VJ, Cheng S, Juwono J, Cuneo R, Kirkish G, Alexander AM, Khan M, Akula A, Caverzasi E, Papinutto N, Stern WA, Pletcher MJ, Marcus GM, Olgin JE, Hauser SL, Gelfand JM, Bove R, Cree BAC, Henry RG. Association of daily physical activity with brain volumes and cervical spinal cord areas in multiple sclerosis. Mult Scler 2023; 29:363-373. [PMID: 36573559 PMCID: PMC9972237 DOI: 10.1177/13524585221143726] [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] [Indexed: 12/28/2022]
Abstract
BACKGROUND Remote activity monitoring has the potential to evaluate real-world, motor function, and disability at home. The relationships of daily physical activity with spinal cord white matter and gray matter (GM) areas, multiple sclerosis (MS) disability and leg function, are unknown. OBJECTIVE Evaluate the association of structural central nervous system pathology with ambulatory disability. METHODS Fifty adults with progressive or relapsing MS with motor disability who could walk >2 minutes were assessed using clinician-evaluated, patient-reported outcomes, and quantitative brain and spinal cord magnetic resonance imaging (MRI) measures. Fitbit Flex2, worn on the non-dominant wrist, remotely assessed activity over 30 days. Univariate and multivariate analyses were performed to assess correlations between physical activity and other disability metrics. RESULTS Mean age was 53.3 years and median Expanded Disability Status Scale (EDSS) was 4.0. Average daily step counts (STEPS) were highly correlated with EDSS and walking measures. Greater STEPS were significantly correlated with greater C2-C3 spinal cord GM areas (ρ = 0.39, p = 0.04), total cord area (TCA; ρ = 0.35, p = 0.04), and cortical GM volume (ρ = 0.32, p = 0.04). CONCLUSION These results provide preliminary evidence that spinal cord GM area is a neuroanatomical substrate associated with STEPS. STEPS could serve as a proxy to alert clinicians and researchers to possible changes in structural nervous system pathology.
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Affiliation(s)
- Valerie J Block
- UCSF Weill Institute for Neurosciences,
Department of Neurology, University of California San Francisco, San
Francisco, CA, USA/Department of Physical Therapy and Rehabilitation
Science, University of California San Francisco, San Francisco, CA,
USA
| | - Shuiting Cheng
- UCSF Weill Institute for Neurosciences,
Department of Neurology, University of California San Francisco, San
Francisco, CA, USA
| | - Jeremy Juwono
- UCSF Weill Institute for Neurosciences,
Department of Neurology, University of California San Francisco, San
Francisco, CA, USA
| | - Richard Cuneo
- UCSF Weill Institute for Neurosciences,
Department of Neurology, University of California San Francisco, San
Francisco, CA, USA
| | - Gina Kirkish
- UCSF Weill Institute for Neurosciences,
Department of Neurology, University of California San Francisco, San
Francisco, CA, USA
| | - Amber M Alexander
- UCSF Weill Institute for Neurosciences,
Department of Neurology, University of California San Francisco, San
Francisco, CA, USA
| | - Mahir Khan
- UCSF Weill Institute for Neurosciences,
Department of Neurology, University of California San Francisco, San
Francisco, CA, USA
| | - Amit Akula
- UCSF Weill Institute for Neurosciences,
Department of Neurology, University of California San Francisco, San
Francisco, CA, USA
| | - Eduardo Caverzasi
- UCSF Weill Institute for Neurosciences,
Department of Neurology, University of California San Francisco, San
Francisco, CA, USA/Department of Brain and Behavioral Sciences, University
of Pavia, Pavia, Italy
| | - Nico Papinutto
- UCSF Weill Institute for Neurosciences,
Department of Neurology, University of California San Francisco, San
Francisco, CA, USA
| | | | - Mark J Pletcher
- Department of Epidemiology and Biostatistics,
University of California San Francisco, San Francisco, CA, USA/Department of
Medicine, University of California San Francisco, San Francisco, CA,
USA
| | - Gregory M Marcus
- Department of Epidemiology and Biostatistics,
University of California San Francisco, San Francisco, CA, USA
| | - Jeffrey E Olgin
- Department of Epidemiology and Biostatistics,
University of California San Francisco, San Francisco, CA, USA
| | - Stephen L Hauser
- UCSF Weill Institute for Neurosciences,
Department of Neurology, University of California San Francisco, San
Francisco, CA, USA
| | - Jeffrey M Gelfand
- UCSF Weill Institute for Neurosciences,
Department of Neurology, University of California San Francisco, San
Francisco, CA, USA
| | - Riley Bove
- UCSF Weill Institute for Neurosciences,
Department of Neurology, University of California San Francisco, San
Francisco, CA, USA
| | - Bruce AC Cree
- BAC Cree UCSF Weill Institute for
Neurosciences, Department of Neurology, University of California, 1651 4th St
Suite 252, San Francisco, San Francisco, CA 94158, USA.
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7
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Cofré Lizama LE, Panisset MG, Peng L, Tan Y, Kalincik T, Galea MP. Optimal sensor location and direction to accurately classify people with early-stage multiple sclerosis using gait stability. Gait Posture 2023; 102:39-42. [PMID: 36889202 DOI: 10.1016/j.gaitpost.2023.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 12/18/2022] [Accepted: 02/13/2023] [Indexed: 03/10/2023]
Abstract
BACKGROUND The local divergence exponent (LDE) has been used to assess gait stability in people with multiple sclerosis (pwMS). Although previous studies have consistently found that stability is lower in pwMS, inconsistent methodologies have been used to assess patients with a broad range of disability levels. QUESTIONS What sensor location and movement direction(s) are better able to classify pwMS at early stages of the disease? METHODS 49 pwMS with EDSS ≤ 2.5 and 24 healthy controls walked overground for 5 min while 3D acceleration data was obtained from sensors placed at the sternum (STR) and lumbar (LUM) areas. Unidirectional (vertical [VT], mediolateral [ML], and anteroposterior [AP]) and 3-dimensional (3D) LDEs were calculated using STR and LUM data over 150 strides. ROC analyses were performed to assess classification models using single and combined LDEs, with and without velocity per lap (VELLAP) as a covariate. RESULTS Four models performed equally well by using combinations of VELLAP, LUM3D, LUMVT, LUMML, LUMAP, STRML, and STRAP (AUC = 0.879). The best model using single sensor LDEs included VELLAP, STR3D, STRML, and STRAP (AUC = 0.878), whereas using VELLAP + STRVT (AUC = 0.869) or VELLAP + STR3D (AUC=0.858) performed best using a single LDE. SIGNIFICANCE The LDE offers an alternative to currently insensitive tests of gait impairment in pwMS at early stages, when deterioration is not clinically evident. For clinical purposes, the implementation of this measure can be simplified using a single sensor at the sternum and a single LDE measure, but speed should be considered. Longitudinal studies to determine the predictive power and responsiveness of the LDE to MS progression are still needed.
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Affiliation(s)
- L Eduardo Cofré Lizama
- Department of Medicine, The University of Melbourne, Parkville, VIC 3050, Australia; School of Allied Health, Human Services and Sport, La Trobe University, Bundoora, VIC 3086, Australia.
| | - Maya G Panisset
- Department of Medicine, The University of Melbourne, Parkville, VIC 3050, Australia
| | - Liuhua Peng
- School of Mathematics and Statistics, The University of Melbourne, Parkville, VIC 3050, Australia
| | - Ying Tan
- Department of Mechanical Engineering, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Tomas Kalincik
- CORe, Department of Medicine, The University of Melbourne, Parkville, VIC 3050, Australia; Neuroimmunology Centre, Department of Neurology, Royal Melbourne Hospital, Australia
| | - Mary P Galea
- Department of Medicine, The University of Melbourne, Parkville, VIC 3050, Australia; Australian Rehabilitation Research Centre, Royal Park Campus, Parkville, VIC 3052, Australia
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8
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Santuz A, Akay T. Muscle spindles and their role in maintaining robust locomotion. J Physiol 2023; 601:275-285. [PMID: 36510697 PMCID: PMC10483674 DOI: 10.1113/jp282563] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 12/09/2022] [Indexed: 12/15/2022] Open
Abstract
Muscle spindles, one of the two main classes of proprioceptors together with Golgi tendon organs, are sensory structures that keep the central nervous system updated about the position and movement of body parts. Although they were discovered more than 150 years ago, their function during movement is not yet fully understood. Here, we summarize the morphology and known functions of muscle spindles, with a particular focus on locomotion. Although certain properties such as the sensitivity to dynamic and static muscle stretch are long known, recent advances in molecular biology have allowed the characterization of the molecular mechanisms for signal transduction in muscle spindles. Building upon classic literature showing that a lack of sensory feedback is deleterious to locomotion, we bring to the discussion more recent findings that support a pivotal role of muscle spindles in maintaining murine and human locomotor robustness, defined as the ability to cope with perturbations. Yet, more research is needed to expand the existing mechanistic understanding of how muscle spindles contribute to the production of robust, functional locomotion in real world settings. Future investigations should focus on combining different animal models to identify, in health and disease, those peripheral, spinal and brain proprioceptive structures involved in the fine tuning of motor control when locomotion happens in challenging conditions.
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Affiliation(s)
- Alessandro Santuz
- Atlantic Mobility Action Project, Brain Repair Centre, Department of Medical Neuroscience, Life Sciences Research Institute, Dalhousie University, Halifax, NS, Canada
| | - Turgay Akay
- Atlantic Mobility Action Project, Brain Repair Centre, Department of Medical Neuroscience, Life Sciences Research Institute, Dalhousie University, Halifax, NS, Canada
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9
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Baifa Z, Xinglong Z, Dongmei L. Muscle coordination during archery shooting: A comparison of archers with different skill levels. Eur J Sport Sci 2023; 23:54-61. [PMID: 34859747 DOI: 10.1080/17461391.2021.2014573] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
This study aimed to compare the muscle coordination of different skill level archers by using the concept of muscle synergies. A total of 28 archers (8 elite, 12 mid-level, and 8 novices) were recruited to participate in this study. Electromyography (EMG) signals were recorded using a 13-channel (Trigno EMG sensor, Delsys Inc., USA) wireless surface EMG system. Fundamental synergies containing time-dependent activation coefficients (motor primitives) and time-invariant muscle weightings (motor modules) were extracted using non-negative matrix factorisation. We observed three fundamental synergies in all groups during archery shooting. The results showed that the centre of activity of the motor primitive of synergy-3 occurred earlier in novice archers than in elite and mid-level archers, which was followed by an increase in the averaged frequency of overlaps. The results also showed a slight difference in the relative muscle contribution of the motor module of synergy-2 and -3 within different groups. These findings revealed that the number of muscle synergies did not depend on the proficiency level; however, more expert archers improved timing management better than less experienced ones. Therefore, we suggest that coaches and athletes focus on optimising the temporal coordination of the follow-through phase.
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Affiliation(s)
- Zhang Baifa
- School of Sport Science, Beijing Sport University, Beijing, People's Republic of China
| | - Zhou Xinglong
- School of Sport Science, Beijing Sport University, Beijing, People's Republic of China
| | - Luo Dongmei
- School of Sport Science, Beijing Sport University, Beijing, People's Republic of China
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10
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Alizadehsaravi L, Bruijn SM, Muijres W, Koster RAJ, van Dieën JH. Improvement in gait stability in older adults after ten sessions of standing balance training. PLoS One 2022; 17:e0242115. [PMID: 35895709 PMCID: PMC9328559 DOI: 10.1371/journal.pone.0242115] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 06/28/2022] [Indexed: 11/18/2022] Open
Abstract
Balance training aims to improve balance and transfer acquired skills to real-life tasks. How older adults adapt gait to different conditions, and whether these adaptations are altered by balance training, remains unclear. We hypothesized that reorganization of modular control of muscle activity is a mechanism underlying adaptation of gait to training and environmental constraints. We investigated the transfer of standing balance training, shown to enhance unipedal balance control, to gait and adaptations in neuromuscular control of gait between normal and narrow-base walking in twenty-two older adults (72.6 ± 4.2 years). At baseline, after one, and after ten training sessions, kinematics and EMG of normal and narrow-base treadmill walking were measured. Gait parameters and temporal activation profiles of five muscle synergies were compared between time-points and gait conditions. Effects of balance training and an interaction between training and gait condition on step width were found, but not on synergies. After ten training sessions step width decreased in narrow-base walking, while step width variability decreased in both conditions. Trunk center of mass displacement and velocity, and the local divergence exponent, were lower in narrow-base compared to normal walking. Activation duration in narrow-base compared to normal walking was shorter for synergies associated with dominant leg weight acceptance and non-dominant leg stance, and longer for the synergy associated with non-dominant heel-strike. Time of peak activation associated with dominant leg stance occurred earlier in narrow-base compared to normal walking, while it was delayed in synergies associated with heel-strikes and non-dominant leg stance. The adaptations of synergies to narrow-base walking may be interpreted as related to more cautious weight transfer to the new stance leg and enhanced control over center of mass movement in the stance phase. The improvement of gait stability due to standing balance training is promising for less mobile older adults.
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Affiliation(s)
- Leila Alizadehsaravi
- Faculty of Behavioural and Movement Sciences, Department of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Sjoerd M. Bruijn
- Faculty of Behavioural and Movement Sciences, Department of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Wouter Muijres
- Faculty of Behavioural and Movement Sciences, Department of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Ruud A. J. Koster
- Faculty of Behavioural and Movement Sciences, Department of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Jaap H. van Dieën
- Faculty of Behavioural and Movement Sciences, Department of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- * E-mail:
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11
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Santuz A, Janshen L, Brüll L, Munoz-Martel V, Taborri J, Rossi S, Arampatzis A. Sex-specific tuning of modular muscle activation patterns for locomotion in young and older adults. PLoS One 2022; 17:e0269417. [PMID: 35658057 PMCID: PMC9165881 DOI: 10.1371/journal.pone.0269417] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 03/22/2022] [Indexed: 12/26/2022] Open
Abstract
There is increasing evidence that including sex as a biological variable is of crucial importance to promote rigorous, repeatable and reproducible science. In spite of this, the body of literature that accounts for the sex of participants in human locomotion studies is small and often produces controversial results. Here, we investigated the modular organization of muscle activation patterns for human locomotion using the concept of muscle synergies with a double purpose: i) uncover possible sex-specific characteristics of motor control and ii) assess whether these are maintained in older age. We recorded electromyographic activities from 13 ipsilateral muscles of the lower limb in young and older adults of both sexes walking (young and old) and running (young) on a treadmill. The data set obtained from the 215 participants was elaborated through non-negative matrix factorization to extract the time-independent (i.e., motor modules) and time-dependent (i.e., motor primitives) coefficients of muscle synergies. We found sparse sex-specific modulations of motor control. Motor modules showed a different contribution of hip extensors, knee extensors and foot dorsiflexors in various synergies. Motor primitives were wider (i.e., lasted longer) in males in the propulsion synergy for walking (but only in young and not in older adults) and in the weight acceptance synergy for running. Moreover, the complexity of motor primitives was similar in younger adults of both sexes, but lower in older females as compared to older males. In essence, our results revealed the existence of small but defined sex-specific differences in the way humans control locomotion and that these are not entirely maintained in older age.
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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
- * E-mail:
| | - Lars Janshen
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany
- Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Leon Brüll
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany
- Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany
- Network Aging Research, Heidelberg University, Heidelberg, Germany
| | - Victor Munoz-Martel
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany
- Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Juri Taborri
- Department of Economics, Engineering, Society and Business Organization, University of Tuscia, Viterbo, Italy
| | - Stefano Rossi
- Department of Economics, Engineering, Society and Business Organization, University of Tuscia, Viterbo, Italy
| | - 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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12
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Cofré Lizama LE, Strik M, Van der Walt A, Kilpatrick TJ, Kolbe SC, Galea MP. Gait stability reflects motor tracts damage at early stages of multiple sclerosis. Mult Scler 2022; 28:1773-1782. [DOI: 10.1177/13524585221094464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background: Gait in people with multiple sclerosis (PwMS) is affected even when no changes can be observed on clinical examination. A sensitive measure of gait deterioration is stability; however, its correlation with motor tract damage has not yet been established. Objective: To compare stability between PwMS and healthy controls (HCs) and determine associations between stability and diffusion magnetic resonance image (MRI) measures of axonal damage in selected sensorimotor tracts. Methods: Twenty-five PwMS (Expanded Disability Status Scale (EDSS) < 2.5) and 15 HCs walked on a treadmill. Stability from sacrum (LDESAC), shoulder (LDESHO) and cervical (LDECER) was calculated using the local divergence exponent (LDE). Participants underwent a 7T-MRI brain scan to obtain fibre-specific measures of axonal loss within the corticospinal tract (CST), interhemispheric sensorimotor tract (IHST) and cerebellothalamic tract (CTT). Correlation analyses between LDE and fibre density (FD) within tracts, fibre cross-section (FC) and FD modulated by FC (FDC) were conducted. Between-groups LDE differences were analysed using analysis of variance (ANOVA). Results: Correlations between all stability measures with CSTFD, between CSTFDC with LDESAC and LDECER, and LDECER with IHSTFD and IHSTFDC were significant yet moderate ( R < −0.4). Stability was significantly different between groups. Conclusions: Poorer gait stability is associated with corticospinal tract (CST) axonal loss in PwMS with no-to-low disability and is a sensitive indicator of neurodegeneration.
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Affiliation(s)
- L Eduardo Cofré Lizama
- School of Allied Health, Human Services and Sports, La Trobe University, Bundoora, VIC, Australia/Department of Medicine and Radiology, The University of Melbourne, Parkville, VIC, Australia
| | - Myrte Strik
- Melbourne Brain Centre Imaging Unit, Department of Radiology, The University of Melbourne, Parkville, VIC, Australia
| | - Anneke Van der Walt
- Department of Neurosciences, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Trevor J Kilpatrick
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia/Florey Department of Neuroscience and Mental Health, The University of Melbourne, Parkville, Australia/Department of Neurology, The Royal Melbourne Hospital, Parkville, VIC, Australia
| | - Scott C Kolbe
- Department of Neurosciences, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Mary P Galea
- Galea Department of Medicine and Radiology, The University of Melbourne, Parkville, VIC, Australia
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13
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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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14
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Munoz-Martel V, Santuz A, Bohm S, Arampatzis A. Proactive Modulation in the Spatiotemporal Structure of Muscle Synergies Minimizes Reactive Responses in Perturbed Landings. Front Bioeng Biotechnol 2021; 9:761766. [PMID: 34976964 PMCID: PMC8716881 DOI: 10.3389/fbioe.2021.761766] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 11/16/2021] [Indexed: 11/18/2022] Open
Abstract
Stability training in the presence of perturbations is an effective means of increasing muscle strength, improving reactive balance performance, and reducing fall risk. We investigated the effects of perturbations induced by an unstable surface during single-leg landings on the mechanical loading and modular organization of the leg muscles. We hypothesized a modulation of neuromotor control when landing on the unstable surface, resulting in an increase of leg muscle loading. Fourteen healthy adults performed 50 single-leg landings from a 30 cm height onto two ground configurations: stable solid ground (SG) and unstable foam pads (UG). Ground reaction force, joint kinematics, and electromyographic activity of 13 muscles of the landing leg were measured. Resultant joint moments were calculated using inverse dynamics and muscle synergies with their time-dependent (motor primitives) and time-independent (motor modules) components were extracted via non-negative matrix factorization. Three synergies related to the touchdown, weight acceptance, and stabilization phase of landing were found for both SG and UG. When compared with SG, the motor primitive of the touchdown synergy was wider in UG (p < 0.001). Furthermore, in UG the contribution of gluteus medius increased (p = 0.015) and of gastrocnemius lateralis decreased (p < 0.001) in the touchdown synergy. Weight acceptance and stabilization did not show any statistically significant differences between the two landing conditions. The maximum ankle and hip joint moment as well as the rate of ankle, knee, and hip joint moment development were significantly lower (p < 0.05) in the UG condition. The spatiotemporal modifications of the touchdown synergy in the UG condition highlight proactive adjustments in the neuromotor control of landings, which preserve reactive adjustments during the weight acceptance and stabilization synergies. Furthermore, the performed proactive control in combination with the viscoelastic properties of the soft surface resulted in a reduction of the mechanical loading in the lower leg muscles. We conclude that the use of unstable surfaces does not necessarily challenge reactive motor control nor increase muscle loading per se. Thus, the characteristics of the unstable surface and the dynamics of the target task must be considered when designing perturbation-based interventions.
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Affiliation(s)
- Victor Munoz-Martel
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany
- Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany
| | - 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
| | - 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
| | - 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
- *Correspondence: Adamantios Arampatzis,
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15
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Cruz-Montecinos C, Pérez-Alenda S, Cerda M, Maas H. Modular reorganization of gait in chronic but not in artificial knee joint constraint. J Neurophysiol 2021; 126:516-531. [PMID: 34133242 DOI: 10.1152/jn.00418.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
It is currently unknown if modular reorganization does occur if not the central nervous system, but the musculoskeletal system is affected. The aims of this study were to investigate 1) the effects of an artificial knee joint constraint on the modular organization of gait in healthy subjects; and 2) the differences in modular organization between healthy subjects with an artificial knee joint constraint and people with a similar but chronic knee joint constraint. Eleven healthy subjects and eight people with a chronic knee joint constraint walked overground at 1 m/s. The healthy subjects also walked with a constraint limiting knee joint movement to 20°. The total variance accounted (tVAF) for one to four synergies and modular organization were assessed using surface electromyography from 11 leg muscles. The distribution of number of synergies were not significantly different between groups. The tVAF and the motor modules were not significantly affected by the artificial knee constraint. A higher tVAF for one and two synergies, as well as merging of motor modules were observed in the chronic knee constraint group. We conclude that in the short-term a knee constraint does not affect the modular organization of gait, but in the long-term a knee constraint results in modular reorganization. These results indicate that merging of motor modules may also occur when changes in the mechanics of the musculoskeletal system is the primary cause of the motor impairment.NEW & NOTEWORTHY It is currently unknown if modular reorganization does occur if not the central nervous system, but the musculoskeletal system is affected. This study showed that in the short-term a knee constraint does not affect the modular organization of gait, but in the long-term a knee constraint results in modular reorganization. These results indicate that modular reorganization may also occur when changes in the mechanics of the musculoskeletal system is the primary cause of the motor impairment.
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Affiliation(s)
- Carlos Cruz-Montecinos
- Physiotherapy in Motion Multispeciality Research Group (PTinMOTION), Department of Physiotherapy, University of Valencia, Valencia, Spain.,Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, Amsterdam, The Netherlands.,Laboratory of Clinical Biomechanics, Department of Physical Therapy, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Sofía Pérez-Alenda
- Physiotherapy in Motion Multispeciality Research Group (PTinMOTION), Department of Physiotherapy, University of Valencia, Valencia, Spain
| | - Mauricio Cerda
- Integrative Biology Program, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Center for Medical Informatics and Telemedicine, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Biomedical Neuroscience Institute, Santiago, Chile
| | - Huub Maas
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, Amsterdam, The Netherlands
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16
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Janshen L, Santuz A, Arampatzis A. Muscle Synergies in Patients With Multiple Sclerosis Reveal Demand-Specific Alterations in the Modular Organization of Locomotion. Front Hum Neurosci 2021; 14:593365. [PMID: 33584221 PMCID: PMC7873056 DOI: 10.3389/fnhum.2020.593365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 12/14/2020] [Indexed: 11/15/2022] Open
Abstract
For patients with multiple sclerosis (MS), deficits in gait significantly reduce the quality of life. Using the concept of muscle synergies, this study investigated the modular organization of motor control during level and inclined walking in MS patients (MSP) compared with healthy participants (HP) to identify the potential demand-specific adjustments in motor control in MSP. We hypothesized a widening of the time-dependent activation patterns (motor primitives) in MSP to increase the overlap of temporally-adjacent muscle synergies, especially during inclined walking, as a strategy to increase the robustness of motor control, thus compensating pathology-related deficits. We analyzed temporal gait parameters and muscle synergies from myoelectric signals of 13 ipsilateral leg muscles using non-negative matrix factorization. Compared with HP, MSP demonstrated a widening in the time-dependent coefficients (motor primitives), as well as altered relative muscle contribution (motor modules), in certain synergies during level and inclined walking. Moreover, inclined walking revealed a demand-specific adjustment in the modular organization in MSP, resulting in an extra synergy compared with HP. This further increased the overlap of temporally-adjacent muscle synergies to provide sufficient robustness in motor control to accomplish the more demanding motor task while coping with pathology-related motor deficits during walking.
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Affiliation(s)
- Lars Janshen
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany
| | - 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
| | - 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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17
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Munoz-Martel V, Santuz A, Bohm S, Arampatzis A. Neuromechanics of Dynamic Balance Tasks in the Presence of Perturbations. Front Hum Neurosci 2021; 14:560630. [PMID: 33584219 PMCID: PMC7874030 DOI: 10.3389/fnhum.2020.560630] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 12/18/2020] [Indexed: 01/13/2023] Open
Abstract
Understanding the neuromechanical responses to perturbations in humans may help to explain the reported improvements in stability performance and muscle strength after perturbation-based training. In this study, we investigated the effects of perturbations, induced by unstable surfaces, on the mechanical loading and the modular organization of motor control in the lower limb muscles during lunging forward and backward. Fifteen healthy adults performed 50 forward and 50 backward lunges on stable and unstable ground. Ground reaction forces, joint kinematics, and the electromyogram (EMG) of 13 lower limb muscles were recorded. We calculated the resultant joint moments and extracted muscle synergies from the stepping limb. We found sparse alterations in the resultant joint moments and EMG activity, indicating a little if any effect of perturbations on muscle mechanical loading. The time-dependent structure of the muscle synergy responsible for the stabilization of the body was modified in the perturbed lunges by a shift in the center of activity (later in the forward and earlier in the backward lunge) and a widening (in the backward lunge). Moreover, in the perturbed backward lunge, the synergy related to the body weight acceptance was not present. The found modulation of the modular organization of motor control in the unstable condition and related minor alteration in joint kinetics indicates increased control robustness that allowed the participants to maintain functionality in postural challenging settings. Triggering specific modulations in motor control to regulate robustness in the presence of perturbations may be associated with the reported benefits of perturbation-based training.
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Affiliation(s)
- Victor Munoz-Martel
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany.,Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany
| | - 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
| | - 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
| | - 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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18
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Ranavolo A, Serrao M, Draicchio F. Critical Issues and Imminent Challenges in the Use of sEMG in Return-To-Work Rehabilitation of Patients Affected by Neurological Disorders in the Epoch of Human-Robot Collaborative Technologies. Front Neurol 2020; 11:572069. [PMID: 33414754 PMCID: PMC7783040 DOI: 10.3389/fneur.2020.572069] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 11/30/2020] [Indexed: 01/07/2023] Open
Abstract
Patients affected by neurological pathologies with motor disorders when they are of working age have to cope with problems related to employability, difficulties in working, and premature work interruption. It has been demonstrated that suitable job accommodation plans play a beneficial role in the overall quality of life of pathological subjects. A well-designed return-to-work program should consider several recent innovations in the clinical and ergonomic fields. One of the instrument-based methods used to monitor the effectiveness of ergonomic interventions is surface electromyography (sEMG), a multi-channel, non-invasive, wireless, wearable tool, which allows in-depth analysis of motor coordination mechanisms. Although the scientific literature in this field is extensive, its use remains significantly underexploited and the state-of-the-art technology lags expectations. This is mainly attributable to technical and methodological (electrode-skin impedance, noise, electrode location, size, configuration and distance, presence of crosstalk signals, comfort issues, selection of appropriate sensor setup, sEMG amplitude normalization, definition of correct sEMG-related outcomes and normative data) and cultural limitations. The technical and methodological problems are being resolved or minimized also thanks to the possibility of using reference books and tutorials. Cultural limitations are identified in the traditional use of qualitative approaches at the expense of quantitative measurement-based monitoring methods to design and assess ergonomic interventions and train operators. To bridge the gap between the return-to-work rehabilitation and other disciplines, several teaching courses, accompanied by further electrodes and instrumentations development, should be designed at all Bachelor, Master and PhD of Science levels to enhance the best skills available among physiotherapists, occupational health and safety technicians and ergonomists.
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Affiliation(s)
- Alberto Ranavolo
- Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, INAIL, Rome, Italy
| | - Mariano Serrao
- Department of Medical and Surgical Sciences and Biotechnologies, Sapienza University of Rome, Rome, Italy
- Movement Analysis LAB, Policlinico Italia, Rome, Italy
| | - Francesco Draicchio
- Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, INAIL, Rome, Italy
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19
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Mileti I, Serra A, Wolf N, Munoz-Martel V, Ekizos A, Palermo E, Arampatzis A, Santuz A. Muscle Activation Patterns Are More Constrained and Regular in Treadmill Than in Overground Human Locomotion. Front Bioeng Biotechnol 2020; 8:581619. [PMID: 33195143 PMCID: PMC7644811 DOI: 10.3389/fbioe.2020.581619] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 09/15/2020] [Indexed: 11/24/2022] Open
Abstract
The use of motorized treadmills as convenient tools for the study of locomotion has been in vogue for many decades. However, despite the widespread presence of these devices in many scientific and clinical environments, a full consensus on their validity to faithfully substitute free overground locomotion is still missing. Specifically, little information is available on whether and how the neural control of movement is affected when humans walk and run on a treadmill as compared to overground. Here, we made use of linear and non-linear analysis tools to extract information from electromyographic recordings during walking and running overground, and on an instrumented treadmill. We extracted synergistic activation patterns from the muscles of the lower limb via non-negative matrix factorization. We then investigated how the motor modules (or time-invariant muscle weightings) were used in the two locomotion environments. Subsequently, we examined the timing of motor primitives (or time-dependent coefficients of muscle synergies) by calculating their duration, the time of main activation, and their Hurst exponent, a non-linear metric derived from fractal analysis. We found that motor modules were not influenced by the locomotion environment, while motor primitives were overall more regular in treadmill than in overground locomotion, with the main activity of the primitive for propulsion shifted earlier in time. Our results suggest that the spatial and sensory constraints imposed by the treadmill environment might have forced the central nervous system to adopt a different neural control strategy than that used for free overground locomotion, a data-driven indication that treadmills could induce perturbations to the neural control of locomotion.
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Affiliation(s)
- Ilaria Mileti
- Department of Mechanical and Aerospace Engineering, Sapienza University of Rome, Rome, Italy
| | - Aurora Serra
- Department of Mechanical and Aerospace Engineering, Sapienza University of Rome, Rome, Italy
| | - Nerses Wolf
- Department of Electrical Engineering and Informatics, Technische Universität Berlin, Berlin, Germany
| | - Victor Munoz-Martel
- 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
| | - Eduardo Palermo
- Department of Mechanical and Aerospace Engineering, Sapienza University of Rome, Rome, Italy
| | - 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
| | - 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
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20
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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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21
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Taborri J, Studer V, Grossi P, Brambilla L, Patanè F, Ferrò MT, Mantegazza R, Rossi S. Reliability and Repeatability Analysis of Indices to Measure Gait Deterioration in MS Patients during Prolonged Walking. SENSORS (BASEL, SWITZERLAND) 2020; 20:E5063. [PMID: 32899946 PMCID: PMC7570495 DOI: 10.3390/s20185063] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/31/2020] [Accepted: 09/04/2020] [Indexed: 11/23/2022]
Abstract
Gait deterioration caused by prolonged walking represents one of the main consequences of multiple sclerosis (MS). This study aims at proposing quantitative indices to measure the gait deterioration effects. The experimental protocol consisted in a 6-min walking test and it involved nine patients with MS and twenty-six healthy subjects. Pathology severity was assessed through the Expanded Disability Status Scale. Seven inertial units were used to gather lower limb kinematics. Gait variability and asymmetry were assessed by coefficient of variation (CoV) and symmetry index (SI), respectively. The evolution of ROM (range of motion), CoV, and SI was computed analyzing data divided into six 60-s subgroups. Maximum difference among subgroups and the difference between the first minute and the remaining five were computed. The indices were analyzed for intra- and inter-day reliability and repeatability. Correlation with clinical scores was also evaluated. Good to excellent reliability was found for all indices. The computed standard deviations allowed us to affirm the good repeatability of the indices. The outcomes suggested walking-related fatigue leads to an always more variable kinematics in MS, in terms of changes in ROM, increase of variability and asymmetry. The hip asymmetry strongly correlated with the clinical disability.
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Affiliation(s)
- Juri Taborri
- Department of Economics, Engineering, Society and Business Organization (DEIM), University of Tuscia, 01100 Viterbo, Italy;
| | - Valeria Studer
- Multiple Sclerosis Center, Neurology Department, Martini Hospital, 10121 Turin, Italy;
| | - Paola Grossi
- Neuroimmunology Center for Multiple Sclerosis, Cerebrovascular Department, ASST Crema, 52242 Crema, Italy; (P.G.); (M.T.F.)
| | - Laura Brambilla
- Operating Units of Autoimmune and Neuromuscular Diseases, IRCCS Foundation Neurological Institute Carlo Besta, 20133 Milano, Italy; (L.B.); (R.M.)
| | - Fabrizio Patanè
- Department of Engineering, Mech. Meas. and Microelectr.lab (M3lab), University Niccolò Cusano, 00166 Rome, Italy;
| | - Maria Teresa Ferrò
- Neuroimmunology Center for Multiple Sclerosis, Cerebrovascular Department, ASST Crema, 52242 Crema, Italy; (P.G.); (M.T.F.)
| | - Renato Mantegazza
- Operating Units of Autoimmune and Neuromuscular Diseases, IRCCS Foundation Neurological Institute Carlo Besta, 20133 Milano, Italy; (L.B.); (R.M.)
| | - Stefano Rossi
- Department of Economics, Engineering, Society and Business Organization (DEIM), University of Tuscia, 01100 Viterbo, Italy;
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22
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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: 8] [Impact Index Per Article: 2.0] [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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