Load-modifying Footwear Intervention Does Lower Knee Adduction Moment in Subjects with Symptoms of Medial Compartment Knee Osteoarthritis

INTRODUCTION A high maximum adduction moment at the knee during walking has been associated with the treatment outcome (Andriacchi 1994) and rate of progression (Miyazaki et al. 2002) of medial compartment knee osteoarthritis (OA). Consequently, many interventions for knee OA are aimed at reducing the maximum knee adduction moment. While footwear modifications, using wedged insoles or shoes (Crenshaw 2000 and Fisher 2002) have been shown to reduce the knee adduction moment, subjects often find such interventions uncomfortable to wear. Fisher et al. 2004 reported that a variable stiffness shoe reduced the knee adduction moment in healthy individuals. However, it has not been shown that a variable stiffness shoe can reduce the adduction moment in subjects with medial compartment knee OA, or if there are certain patients that are not responsive to a variable stiffness shoe. The purpose of this study was to test the following hypothesis: the variable stiffness shoes will lower the knee adduction moment in the affected leg of individuals with symptoms of medial compartment knee OA, compared to the subjects’ personal shoes and control shoes.