The Effect of Concurrent Ankle and Hip Positions on Hamstring Function in Athletes

Previous studies have suggested that ankle position and hip position can influence hamstring strength, but none have considered the influence of both joint positions at the same time.

This study aimed to investigate the effect of ankle and hip position on peak torque (PT), normalized PT (NPT), angle of PT (APT), and surface electromyographic (SEMG) activity during isokinetic knee flexion.

In this within-subject study design, thirteen physically active men in a single session performed three maximal isokinetic unilateral knee flexion repetitions in four different ankle and hip positions: sitting with dorsal/plantar flexion and supine with dorsal/plantar flexion at two angular velocities of 60 and 180°/s on the isokinetic dynamometer. The individual SEMG activity of the gastrocnemius (GL), biceps femoris (BFl), and semitendinosus (ST) muscles was detected using a wireless SEMG system.

Ankle and hip positions had a significant impact on the PT, NPT, and APT (p < 0.05), but did not affect SEMG activity of BFl, ST, and GL muscles for both angular velocities (p > 0.109). Specifically, the flexed hip and dorsiflexed ankle provided the greatest torque production, while the extended hip and plantarflexed ankle led to a decrease in hamstring torque production. An increase in angular velocity also led to an increase in APT.

Both hip and ankle positions have a significant impact on the PT, NPT, and APT, but not on BFl, ST, and GL activation during maximal knee flexion, for both angular velocities, 60 and 180°/s.