It is hypothesised that laterally wedged insoles will result in reduced knee pain and cartilage volume loss after 12 months of wear, compared to control insoles. People with symptomatic knee osteoarthritis will be recruited from the community and randomised to wear either laterally wedged insoles or control insoles for 12 months. Patients will be assessed at baseline and at 12 months.

Inclusion Criteria:

• Eligibility will be confirmed by radiographic and clinical examination
• People with medial tibiofemoral joint OA fulfilling American College of Rheumatology classification criteria and reporting average knee pain on walking >3 on an 11-point scale
• varus knee malalignment on standing anteroposterior lower limb x-ray.

Exclusion Criteria:

• advanced radiographic knee OA (Kellgren and Lawrence stage 4
• knee surgery or intra-articular corticosteroid injection within 6 months
• current or past (within 4 weeks) oral corticosteroid use
• systemic arthritic conditions
• history of tibiofemoral/patellofemoral joint replacement or tibial osteotomy
• any other muscular, joint or neurological condition affecting lower limb function
• ankle/foot pathology or pain that precludes the use of insoles
• use of foot orthotics within past 6 months and
• use of footwear that does not accomodate an insole.