Muscle synergies and muscle networks in multiple frequency components in post-stroke patients

• Published in: Biomedical signal processing and control Vol. 95; p. 106417
• Main Authors: Zhao, Kunkun, Feng, Yizhou, Li, Liang, Zhou, Yuxuan, Zhang, Zhisheng, Li, Jianqing
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.09.2024
• Subjects: Electromyographic; EMG; Frequency components; Muscle networks; Muscle synergies; Stroke; Stroke; Electromyographic; Muscle networks; Frequency components; EMG; Muscle synergies
• ISSN: 1746-8094; 1746-8108
• DOI: 10.1016/j.bspc.2024.106417

•Muscle synergies and muscle networks were extracted from three distinct frequency components (20–450 Hz, 20–30 Hz, 30–450 Hz).•The low-frequency component (20–30 Hz) is capable of performing muscle synergy analysis as done in the full-band (20–450 Hz).•Alterations in muscle coordination induced by stroke are evident in the full-band in muscle network analysis. As a neural control strategy employed by the central nervous system to control movements, the extraction of muscle synergies from a broad range of electromyographic signals has been the focus. Nevertheless, recent coherence analysis demonstrates distinct roles played in low-frequency components in motor control. This suggests that muscle synergies extracted from the low-frequency components can capture movement characteristics as done in the full-band. To investigate this issue, muscle synergies were extracted from three distinct frequency components (20–450 Hz, 20–30 Hz, 30–450 Hz) during spatial reaching movements in a group of healthy and stroke subjects. Synergy similarities were computed both within frequencies and between groups, and complex network analysis was conducted based on the group-averaged synergies. Results showed that the number and structure of muscle synergies, as well as network metrics, identified from the full-band (20–450 Hz) and low-frequency (20–30 Hz) exhibited high similarity between groups. These patterns diverged from those observed in high-frequency (30–450 Hz). The stroke did not induce significant alterations in muscle synergies. However, higher network metrics were identified in the full-band for one synergy. This study demonstrated the capacity of low-frequency components to perform muscle synergy analysis. These findings can help better understand the neural drive and motor control, potentially advancing the assessment of motor function and rehabilitation strategies.