Reduced Knee Joint Loading With Lateral and Medial Wedge Insoles for Management of Knee Osteoarthritis: a Randomized Controlled Trial

Knee osteoarthritis (OA) is commonly treated using laterally wedged insoles. Although these insoles typically reduce knee abduction moments (KAM) - a variable associated with knee osteoarthritis - and thus are believed to be beneficial for OA management, recent research has indicated that in some cases lateral wedge insoles actually increase knee joint loads. In such cases, a medial wedge may be more appropriate.

The purpose of this study is to evaluate the influence of reduced KAMs on pain over 3-months for patients with knee OA. It is hypothesized that pain reduction will be directly related to KAM reduction.

Forty-six participants with knee OA will be recruited to participate. Each will undergo biomechanical gait analysis to determine the wedge type that most greatly reduces knee adduction moments. In addition, each participant will undergo a Dual Energy X-Ray Absorptiometry (DXA) scan to quantify adiposity. Finally, participants will complete a series of questionnaires to evaluate pain, function, physical activity, footwear comfort and injury history. Participants will be randomized into either a wait list control group (no insole) or experimental group (medial or lateral wedged insole), and monitored for 3 months.

Changes to pain, function, comfort and physical activity from baseline to 3 months will be assessed within the control and experimental groups. Regression analyses will be conducted on the experimental group to determine if a relationship exists between reduced KAMs and reduced pain over 3 months. Comparisons will also be made between the control and experimental groups.