Inclusion Criteria:  people with radiographic TF OA fulfilling American College of Rheumatology classification criteria reporting average knee pain on walking > 3 on an 11-point scale (0-10) in at least one knee pain or tenderness predominantly located on the medial knee.  Exclusion Criteria:  medial TF joint space width greater than lateral Kellgren/Lawrence (K/L) grade 4 knee surgery or intra-articular corticosteroid injection in the past 6 months uncomfortable walking on treadmill for 20 minutes unable to walk without a walking aide inflammatory arthritis other musculoskeletal or neurological disorders that affect gait patterns currently receiving physical therapy