Avtor/Urednik		Hagedoorn, Lotte C.; Zadravec, Matjaž; Olenšek, Andrej; Asseldonk, Edwin van; Matjačić, Zlatko
Naslov		The existence of shared muscle synergies underlying perturbed and unperturbed gait depends on walking speed
Tip		članek
Vol. in št.		Letnik iss. 4, št. art. 2135
Leto izdaje		2022
Obseg		str. 1-14
ISSN		2076-3417
Jezik		eng
Abstrakt		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.
Proste vsebinske oznake		pertubirana hoja elektromiografija negativna matrična faktorizacija mišične sinergije hitrost hoje nadzor ravnotežja perturbed walking electromyography non-negative matrix factorization muscle synergies gait speed balance control