Changes of joint moments in the gait of normal subjects wearing laterally wedged insoles

Objective: The purpose of this study was to assess the kinematic and kinetic effects of wearing a laterally wedged insole on the knee joint moment during gait, specifically in the frontal plane, in normal healthy adults. Design: Motion analyses were conducted with (1) a three-dimensional motion analysis system and (2) ground reaction force analysis using force platforms when subjects walked under three different insole conditions: no wedge, a low wedge with a 3-degree lateral angle, and a high wedge with a 6-degree lateral angle. Results: The high-wedge insole significantly reduced the knee joint varus moment during gait compared with the gait with the no-wedge insole. The actual segment angles at the subtalar and knee joints did not show any changes due to insole conditions. In contrast, the subtalar joint valgus moment increased for the high-wedge insole. This finding was correlated with a greater moment arm of the subtalar Joint valgus moment with the high-wedge insole. Conclusions: These results indicate that, under dynamic conditions, the subjects wearing laterally wedged insoles had both changes of moments at the subtalar and knee joints via the more laterally shifted location of the center of pressure.