Biomechanical effects of lateral and medial wedge insoles on unilateral weight bearing

Abstract

[Purpose] Lateral wedge insoles reduce the peak external knee adduction moment and are advocated for patients with knee osteoarthritis. However, some patients demonstrate adverse biomechanical effects with treatment. In this study, we examined the immediate effects of lateral and medial wedge insoles under unilateral weight bearing. [Subjects and Methods] Thirty healthy young adults participated in this study. The subjects were assessed by using the foot posture index, and were divided into three groups: normal foot, pronated foot, and supinated foot groups. The knee adduction moment and knee-ground reaction force lever arm under the studied conditions were measured by using a three-dimensional motion capture system and force plates. [Results] In the normal and pronated groups, the change in knee adduction moment significantly decreased under the lateral wedge insole condition compared with the medial wedge insole condition. In the normal group, the change in the knee-ground reaction force lever arm also significantly decreased under the lateral wedge insole condition than under the medial wedge insole condition. [Conclusion] Lateral wedge insoles significantly reduced the knee adduction moment and knee-ground reaction force lever arm during unilateral weight bearing in subjects with normal feet, and the biomechanical effects varied according to individual foot alignment.

The Effects of Short-Term Wearing of Customized 3D Printed Single-Sided Lateral Wedge Insoles on Lower Limbs in Healthy Males: A Randomized Controlled Trial

“…Although the increase in GRF was small in this study, the LWI reduced the moment arm in the early and late stages of horizontal walking, similar to the results of previous studies [26,27]. The reduction of ground reaction torque and knee adduction torque was similar under all walking conditions.…”

Effects of footwear on the knee adduction moment in medial knee osteoarthritis: classification criteria for flat flexible vs stable supportive shoes

“…While some studies have shown reductions in the KAM when using a combined lateral wedge/medial arch support 24,25 , it appears that the reduction in KAM is largely driven by the lateral wedge orthotic 26,27 . In fact, findings suggest that the KAM is increased when a medial arch support is used in isolation 25,28,29 . However, recent additions to the market also include shoes with flat, thin, flexible soles which minimize interference with natural foot motion during walking.…”

The immediate effects of foot pressure based insole on ankle dorsiflexion range of motion, postural sway, and muscle activation in healthy adults with genu varum

“…A lateral wedge insole has been commonly used for genu varum for osteoarthritis [7][8][9] because it reduce pain [10] and knee adduction moment [11]. It also improves functions involved in physical activity, such as walking distance [7] and static balance [12].…”