Synergy in Motion Exploring the Similarity and Variability of Muscle Synergy Patterns in Healthy Individuals

Luying Feng, Luying

Abstract:

Background: Recent studies suggest that muscle synergy patterns can be a guide for diagnosis and
rehabilitation.
Research question: Does human’s lower limb synergy pattern significantly change with changes in
walking speed? Are there large differences in synergy patterns among different healthy
individuals?
Methods: 22 healthy subjects from an open-source datasets were included. Non-negative matrix
factorization was applied to identify the module composition of surface electromyography(sEMG)
data, and the similarity index was adopted to quantify the overall similarity between synergy
patterns.
Results: Results demonstrated that healthy individuals have their own intrinsic muscle recruit
ment and coordination characteristics for locomotion at various speeds, additionally, their syn
ergy patterns exhibit predictability under speed variations.
Significance: This study develop reference synergy patterns for the lower limbs across 28 different
walking speeds. The developed synergy patterns and the above findings may guide the study of
gait synergy in rehabilitation and assistance.