The effect of resistance training on an unstable surface with blood flow restriction on the temporal patterns and the number of muscle synergies in the elderly with a history of falling while walking: a preliminary study

as getting old, neuromuscular adaptations decrease and the fall rates increase. Analyzing the temporal patterns of muscle synergy can provide a useful framework for describing and interpreting neuromuscular system’s adaptation. Therefore, the aim of the present study was to investigate the effect of unstable resistance training with blood flow restriction on the temporal patterns and the number of muscle synergies of elderly with a history of falling while walking.

27 elderly men (62±1.5 years old) with a history of falling were randomly assigned into three groups of unstable resistance training without blood flow restriction, unstable resistance training with blood flow restriction and control. The training program consisted of squat training with body weight on unstable surface for 4 weeks and three sessions per week. Before and after the intervention, electromyography signals from eight muscles of the lower limb were recorded during walking to extract the number of synergies, the amount of muscle use, the duration of muscle use, and the stability of neural commands. Kruskal-Wallis test, Paired Wilcoxon test and analysis of covariance test with Bonferroni post hoc test were used (P˂0/05).

Results showed that although there is significant difference in the number of muscle synergy between the control group and the resistance training group on the unstable surface with blood flow restriction (p=0.002) and without blood flow restriction (p=0.013); But no statistically significant difference was observed between the two training groups (P=0.23). Also, the amount of muscles use and duration of muscles use decreased in both training groups with blood flow restriction (P=0.0001) and without blood flow restriction (P=0.0001). However, statistically significant difference was observed only in the stability variable of neural commands between both training groups with and without blood flow restriction (P=0.005).

Unstable resistance training with blood flow restriction only improves the stability index of neural commands during walking compared to unstable resistance training without blood flow restriction in elderly people with falls’ history.