2025 Volume 4 Issue 1 Pages 1-11
Objective: The aim of this study was to clarify the effect of ankle foot orthosis (AFO) on the reproducibility of kinematic data and spatiotemporal patterns of muscle synergy in a stroke patient with occasional toe-catching.
Method: The case was a woman in her 70s who had hemiplegic stroke. Walking with comfortable speed was performed in two conditions with and without wearing AFO, surface electromyography was used to collect muscle activity from paretic lower limb muscles during 10 gait cycles. Non-negative matrix factorization was used to extract muscle synergies and their spatiotemporal patterns were compared between both conditions with and without AFO. To compare the reproducibility of the spatiotemporal pattern of muscle synergy and the time series changes in lower limb joint angles between the two conditions, cross-correlation analysis and cosine similarity were calculated based on the date on the obtained from 10 gait cycles.
Results: Two types of muscle synergies were extracted in both conditions, which were activated during stance and swing phases. The similarity of the spatiotemporal patterns between the both conditions was high(>0.990) for the two types of muscle synergies. The cross-correlation values between the lower limb joint angle and the temporal pattern of muscle synergy activated during the swing phase were significantly lower in the without AFO condition. Furthermore, the cosine similarity in this muscle synergy was significantly lower in the without AFO condition.
Conclusion: We suggest that AFO may have contributed to improved reproducibility of lower limb joint movements through improved reproducibility of the spatiotemporal pattern of muscle synergy.
