Obesity is strongly associated with osteoarthritis, and in particular a dose dependent relationship has been found to exist between BMI and risk of developing osteoarthritis of the knees. Excessive osteoarthritis of otherwise healthy joints is known to contribute towards osteoarthritis, but obesity is also a risk factor for developing osteoarthritis in non-weight-bearing joints, and current research indicates a more complex relationship exists between osteoarthritis and obesity than can be explained by biomechanical stress alone.