Influence of foot strike patterns on local dynamic stability of the lower extremity

This study examined how foot strike patterns affect lower extremity stability during running. Ten habitual forefoot and ten habitual rearfoot strike runners performed a 15-minute running trial on an instrumented treadmill at a speed of 3 m/s, with motion capture system collecting three-dimensional kinematics of the lower extremity. The local dynamic stability of the hip, knee, and ankle joints in each of the movement planes was calculated using the maximum Lyapunov exponent. The results demonstrated that forefoot strike runners exhibited higher knee stability in the sagittal plane compared with rearfoot strike runners. Additionally, the ankle stability in the frontal plane was potentially influenced by running duration. These findings can provide direct evidence for common knee injuries in rearfoot strike runners and suggest that the application of local dynamic stability can offer valuable insights into the mechanisms of running-related injuries.