- width with LWAS could be another mechanism for the further reduction of the moment with that type of insole. The analyses of biomechanical parameters at subtalar joints revealed that the change of valgus angle at the joints was smaller with LWAS than with LW, while the magnitude of subtalar adduction moment was similar for LW and LWAS. This may indicate that LWAS could allow the subject to walk in a more natural manner, while exerting load shift similar to that with LW. Conclusions: The addition of an arch support to the laterally wedged insole reduced knee adduction moment more efficiently than the conventional laterally wedged insoles, presumably through the reduction of the toe-out angle and step width. Current results also indicated that the conventional laterally wedged insole could have potential drawbacks to induce toe-out gait with wider stance, which might impair its biomechanical effects. The result of insole therapy for medial knee OA could be significantly improved by the addition of an arch support to the laterally wedged insole.