Obesity is a strong independent risk factor for musculoskeletal pain and injury. In fact it nearly doubles the risk of chronic pain in the elderly. Compared with persons of normal weight, the odds of sustaining a musculoskeletal injury are 15% higher for persons with a BMI (body mass index) of 25-30 and 48% higher for those whose BMI is equal to and greater than 40.
Studies also confirm a statistically significant link between obesity and incidence of osteoarthritis. Compared with patients who have a normal BMI, the need for a total knee arthroplasty (knee replacement) is estimated to be 8.5 times higher in patients with a BMI greater than 30, 18.7 times higher in patients with a BMI greater than 35, and 32.7 times higher in patients with a BMI of 40 or greater.
Source: Journal of the American Academy of Orthopedic Surgeons, November 2014