The development of medial knee osteoarthritis (OA) has been attributed to overloading of the medial compartment articular cartilage. Therefore, treatment strategies are often focused on reducing medial compartment loads. Gait modification represents a non-invasive method for achieving this goal. Previous studies have shown that a variety of gait modifications (e.g., toeing out, increased medial-lateral trunk sway, walking with medialized knees (i.e., medial thrust gait)) are effective in reducing the external knee adduction moment. Although the external knee adduction moment is often used as a surrogate measure of medial compartment force, a recent study showed that reductions in the external knee adduction moment do not guarantee reductions in medial compartment force. Therefore, direct measurements of changes in medial contact force are important for determining the effectiveness of gait modifications.