Immediate effects of varying cadence in bicycle ergometry on characteristics of gait and lower extremity motor activity in frail older adults

Aim This study examined the immediate effects of a 5-min pedaling period with varying cadence (VC) on various dimensions of gait function in frail older adults. Methods Twenty frail older adults (mean age 77.2 years) were randomly assigned to one of two groups: the VC group or the constant cadence (CC) group. Each group performed bicycle ergometry for 5 min at 20 W. The CC group pedaled continuously at a CC of 50 rpm, while the VC group pedaled continuously at cadences of 45, 55, 65, 55, and 45 rpm, in this order, changing cadence every 60 s. Immediately before and after bicycle ergometry, the following measurements were carried out: gait performance, muscle activity (electromyographic analysis), and knee motion analysis. Results CC did not significantly affect any of the measured parameters. In contrast, the VC group showed improvement in all three parameters: an increase in normal gait speed and cadence (p < 0.01), a reduction in the activation period (p < 0.04) and CI-THIGH (antagonistic coactivation time between knee flexor and extensor muscles, p < 0.05), and an increase in maximum knee extension angular velocity (p < 0.01). Conclusion A short period of VC bicycle ergometry with low work intensity was effective in immediately improving gait function in frail older adults.