Biomechanical comparison of human trunk and thigh muscle activity during walking and horseback riding activity

Hippotherapy is a physical therapy tool that utilizes horseback riding to improve strength, coordination, gait, and balance. These benefits may be linked to similarities in kinematics and muscle activation between horseback riding and normal human gait, but this is not well represented in the literature, especially for muscle activation. The purpose of this study was to investigate the relationships between muscle activation of horseback riding and healthy human gait.

The muscle activation of nine healthy female participants (age 18-22) were recorded during walking and horseback riding trials using surface electromyography (EMG). Muscles analyzed include rectus abdominis, lumbar erector spinae, rectus femoris and biceps femoris. Activation waveforms during walking and riding were generated, and from this average and maximum contraction magnitudes were recorded.

Average muscle activation was significantly greater in riding for the left (p = 0.008) and right (p = 0.04) biceps femoris. Additionally, average and maximal activation of the left erector spinae were significantly greater in riding (W = 4; critical value for W at n = 9 is 5). Remaining differences in muscle activation between walking and riding were non-significant.

Peak and average muscle activation magnitude across the gait cycle were similar for most muscle groups. When present, differences were greater in riding. Despite these similarities, EMG waveforms displayed more predictable temporal patterns in walking.

These findings suggest that hippotherapy could be used to elicit muscle excitation similar to that of normal gait, which may have promising implications for rehabilitation targeting gait correction.