Wedged footwear insoles can reduce peak knee adduction moments during gait, which are associated with knee osteoarthritis development and progression; however, randomized trials have been mixed in terms of wedged insole clinical efficacy. To address methodological and technical limitations of past studies, the purposes of this thesis were to (1) identify the most suitable footwear control condition, from a biomechanical perspective, (2) identify a method that can predict the effect of wedged insoles on resultant knee adduction moments, and (3) evaluate the effects of a reduced knee adduction moment intervention on clinical outcomes for individuals with knee osteoarthritis.
In fifteen healthy individuals, three sham footwear conditions were compared against participant’s own footwear to determine if sham footwear were biomechanically inert. It was found that all three sham footwear conditions significantly altered biomechanical variables during gait, including the knee adduction moment, and thus participant’s own footwear was recommended as the best control condition, from a biomechanical perspective, for future clinical studies.
In fifteen healthy and nineteen knee osteoarthritis participants, a method was discovered that utilizes two dimensional video data from a single stepping motion to predict the change in knee adduction moment induced by wedged insoles during walking. When compared to actual walking data, the method successfully identified the correct insole intervention for 12/15 healthy and 17/19 knee osteoarthritis individuals. It is hoped this method may be implemented into clinical settings for improved footwear prescription capability for individuals with knee osteoarthritis.
Finally, a three month randomized trial was conducted. Biomechanical and clinical data were collected from 48 individuals with knee osteoarthritis at baseline, and participants were randomized to either an insole (knee adduction moment reduction) group, or a waitlist control group. At follow-up, no significant differences were noted between groups in terms of change in pain. Knee adduction moment reduction was not associated with reduced pain for the insole group. These data suggest that reduction of knee adduction moments do not confer a clinical benefit in the short term, but do not rule out the possibility that reduced moments are beneficial from a prevention standpoint, or for long term management.