Device-assisted calf-raise training combining high-speed and eccentric exercises improves gait speed in older adults

Plantar flexors are critical for mobility in older adults. Although movement velocity contributes to gait performance in addition to strength, few interventions target both plantar flexor strength and velocity. To address this gap, we developed a novel device to support a program incorporating both high-speed and eccentric plantar-flexor exercises and examined whether this device-assisted program improves plantar flexion strength, movement velocity, and gait speed. In a nonrandomized controlled trial, 40 older adults were allocated to either a training group ( n = 20) or a control group ( n = 20). The training group undertook a 10-week calf-raise program using a custom-built device, whereas the control group continued usual activities. The program was performed twice daily, 5 days per week, and included high-speed calf-raises (20 repetitions) and eccentric calf-raises (30 repetitions). Of the 19 participants who initiated the intervention, 18 completed the program (retention rate, 94.7%), and all achieved the prescribed target dose (adherence, 100%). Compared with controls, the training group showed greater improvements in gait speed (+ 0.17 m/s) and plantar flexion strength (+ 7.5 kgf) and movement velocity (+ 104.9 °/s). These findings suggest that device-assisted calf-raise training may improve plantar flexor function and gait performance in older adults. Trial registration: UMIN-CTR, UMIN000052504; 15/10/2023.