Effects of wear of the lateral heel of shoe soles on lower extremity joints

Abstract

Objective: The function of shoes decreases in accordance with the wear of shoe soles. Most markedly where the lateral heel first contacts the ground during gait. However, it has not been clarified how walking with worn-out soles affects the burden of the lower extremity joints. The purpose of this study was to show the effect of the worn-out soles on the joint load during gait.

Methods: Fifteen healthy individuals participated in this study. Gait at comfortable speed was measured with both without worn-out soles and normal soles using a 3D motion analysis system and force plates.

Results: No differences were found in the varus angle and moment of the knee joint between the two conditions. However, a significant increase in peak adductive moment of the hip joint just after initial contact and a significant decrease of knee flexion angle and knee extension moment in loading response were found in the worn-out sole condition compared to the normal insole condition.

Discussions: The results showed that continuous walking with the worn-out soles induces a decrease in knee flexion in early stance and would increase the risk in the knee joint.