The Existence of Shared Muscle Synergies Underlying Perturbed and Unperturbed Gait Depends on Walking Speed
Muscle synergy theory assumes that the central nervous system generates a wide range of complex motor outputs by recruiting muscle synergies with different strengths and timings. The current understanding is that a common set of muscle synergies underlies unperturbed as well as perturbed walking at...
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MDPI AG
2022-02-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/12/4/2135 |
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| author | Lotte Hagedoorn Matjaž Zadravec Andrej Olenšek Edwin van Asseldonk Zlatko Matjačić |
| author_facet | Lotte Hagedoorn Matjaž Zadravec Andrej Olenšek Edwin van Asseldonk Zlatko Matjačić |
| author_sort | Lotte Hagedoorn |
| collection | DOAJ |
| description | Muscle synergy theory assumes that the central nervous system generates a wide range of complex motor outputs by recruiting muscle synergies with different strengths and timings. The current understanding is that a common set of muscle synergies underlies unperturbed as well as perturbed walking at self-selected speeds. However, it is not known whether this is the case for substantially slower walking. The aim of this study was to investigate whether a shared set of muscle synergies underlies balance recovery responses following inward- and outward-directed perturbations in the mediolateral direction at various perturbation onsets and walking speeds. Twelve healthy subjects walked at three walking speeds (0.4, 0.6, and 0.8 m/s) on a treadmill while perturbations were applied to the pelvis using the balance assessment robot. A set of sixteen EMG signals, i.e., eight muscles per leg, was measured and decomposed into muscle synergies and weighting curves using non-negative matrix factorization. The muscles included were left and right tibialis anterior, soleus, gastrocnemius medialis, gastrocnemius lateralis, rectus femoris, hamstring, gluteus medius, and gluteus maximus. In general, four muscle synergies were needed to adequately reconstruct the data. Muscle synergies were similar for unperturbed and perturbed walking at a high walking speed (0.8 m/s). However, the number of similar muscle synergies between perturbed and unperturbed walking was significantly lower for low walking speeds (0.4 and 0.6 m/s). These results indicate that shared muscle synergies underlying perturbed and unperturbed walking are less present during slow walking compared to fast walking. |
| first_indexed | 2024-03-09T22:40:34Z |
| format | Article |
| id | doaj.art-5daf1ca858554704801ae6504c18e428 |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-09T22:40:34Z |
| publishDate | 2022-02-01 |
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| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-5daf1ca858554704801ae6504c18e4282023-11-23T18:39:52ZengMDPI AGApplied Sciences2076-34172022-02-01124213510.3390/app12042135The Existence of Shared Muscle Synergies Underlying Perturbed and Unperturbed Gait Depends on Walking SpeedLotte Hagedoorn0Matjaž Zadravec1Andrej Olenšek2Edwin van Asseldonk3Zlatko Matjačić4Department of Rehabilitation, Radboud University Medical Center, 6525 GA Nijmegen, The NetherlandsResearch and Development Unit, University Rehabilitation Institute Republic of Slovenia, 1000 Ljubljana, SloveniaResearch and Development Unit, University Rehabilitation Institute Republic of Slovenia, 1000 Ljubljana, SloveniaDepartment of Biomechanical Engineering, University of Twente, 7522 NB Enschede, The NetherlandsResearch and Development Unit, University Rehabilitation Institute Republic of Slovenia, 1000 Ljubljana, SloveniaMuscle synergy theory assumes that the central nervous system generates a wide range of complex motor outputs by recruiting muscle synergies with different strengths and timings. The current understanding is that a common set of muscle synergies underlies unperturbed as well as perturbed walking at self-selected speeds. However, it is not known whether this is the case for substantially slower walking. The aim of this study was to investigate whether a shared set of muscle synergies underlies balance recovery responses following inward- and outward-directed perturbations in the mediolateral direction at various perturbation onsets and walking speeds. Twelve healthy subjects walked at three walking speeds (0.4, 0.6, and 0.8 m/s) on a treadmill while perturbations were applied to the pelvis using the balance assessment robot. A set of sixteen EMG signals, i.e., eight muscles per leg, was measured and decomposed into muscle synergies and weighting curves using non-negative matrix factorization. The muscles included were left and right tibialis anterior, soleus, gastrocnemius medialis, gastrocnemius lateralis, rectus femoris, hamstring, gluteus medius, and gluteus maximus. In general, four muscle synergies were needed to adequately reconstruct the data. Muscle synergies were similar for unperturbed and perturbed walking at a high walking speed (0.8 m/s). However, the number of similar muscle synergies between perturbed and unperturbed walking was significantly lower for low walking speeds (0.4 and 0.6 m/s). These results indicate that shared muscle synergies underlying perturbed and unperturbed walking are less present during slow walking compared to fast walking.https://www.mdpi.com/2076-3417/12/4/2135perturbed walkingelectromyographynon-negative matrix factorizationmuscle synergiesgait speedbalance control |
| spellingShingle | Lotte Hagedoorn Matjaž Zadravec Andrej Olenšek Edwin van Asseldonk Zlatko Matjačić The Existence of Shared Muscle Synergies Underlying Perturbed and Unperturbed Gait Depends on Walking Speed Applied Sciences perturbed walking electromyography non-negative matrix factorization muscle synergies gait speed balance control |
| title | The Existence of Shared Muscle Synergies Underlying Perturbed and Unperturbed Gait Depends on Walking Speed |
| title_full | The Existence of Shared Muscle Synergies Underlying Perturbed and Unperturbed Gait Depends on Walking Speed |
| title_fullStr | The Existence of Shared Muscle Synergies Underlying Perturbed and Unperturbed Gait Depends on Walking Speed |
| title_full_unstemmed | The Existence of Shared Muscle Synergies Underlying Perturbed and Unperturbed Gait Depends on Walking Speed |
| title_short | The Existence of Shared Muscle Synergies Underlying Perturbed and Unperturbed Gait Depends on Walking Speed |
| title_sort | existence of shared muscle synergies underlying perturbed and unperturbed gait depends on walking speed |
| topic | perturbed walking electromyography non-negative matrix factorization muscle synergies gait speed balance control |
| url | https://www.mdpi.com/2076-3417/12/4/2135 |
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