The overall objective of this project is to determine whether the provision of a pneumatic knee brace in patients with medial knee osteoarthritis (OA) improves knee mechanics. Secondary objectives will be to assess if the brace relieves knee pain and improves function. We will test the hypothesis that compared to the control treatment (see below for the definition) the use of a pneumatic knee brace is effective in medial knee OA.

This study is closed to enrollment and in the data analysis phase

Inclusion Criteria:

• knee pain, aching or stiffness on most of the past 30 days
• x-ray verified predominant medial tibiofemoral osteoarthritis (TFOA)
• overall pain that is due to the medial TFOA (versus being referred from the back, hips, or other pre-existing conditions)
• ambulatory persons

Exclusion Criteria:

• use of a crutch, walker, or wheelchair or cane more than 50% of the time
• history of Deep Vein Thrombosis
• Pain emanating more from back or hip than from knee
• Low pain score on WOMAC
• predominant patellofemoral disease or knee pathology other than medial compartment OA likely to be causing their knee pain.
• Planning to move from area within 1 month of study screening.
• Unable to fit the brace properly
• BMI greater than 35
• corticosteriod injections in the past month
• Bilateral total knee replacements or plan for TKR
• Other types of arthritis including Rheumatoid Arthritis, Systemic Lupus Erythematosus, gout, psoriatic arthritis, pseudogout.
• woman who are pregnant (due to x-rays taken to determine eligibility)