A wearable electromyography-controlled functional electrical stimulation system improves balance, gait function, and symmetry in older adults

BACKGROUND: Wearable technologies have been developed for healthy aging. The technology for electromyography (EMG)-controlled functional electrical stimulation (FES) systems has been developed, but research on how helpful it is in daily life has been insufficient. OBJECTIVE: The purpose of this study was to investigate the effect of the EMG-controlled FES system on muscle morphology, balance, and gait in older adults. METHODS: Twenty-nine older adults were evaluated under two randomly assigned conditions (non-FES and FES assists). Muscle morphology, balance, gait function, and muscle effort during gait were measured using ultrasonography, a physical test, a gait analysis system, and EMG. RESULTS: The EMG-controlled FES system improved gait speed by 11.1% and cadence by 15.6% (P< 0.01). The symmetry ratio of the bilateral gastrocnemius was improved by 9.9% in the stance phase and 11.8% in the swing phase (P< 0.05). The degrees of coactivation of the knee and ankle muscles were reduced by 45.1% and 50.5%, respectively (P< 0.05). Balance improved by 6–10.7% (P< 0.01). CONCLUSION: The EMG-controlled FES system is useful for balance and gait function by increasing muscle symmetry and decreasing muscle coactivation during walking in older adults.