Studies in the past have shown a statistically significant association between use of lateral wedge insoles and lower pain in medical knee osteoarthritis. However, among trials comparing wedge insoles with neutral insoles, there was no significant association between use of wedge insoles and reduction in knee pain, according to a recent study at the University of Manchester, England.
Mathew J. Parkes, B.Sc, and colleagues conducted a search of the medical literature to identify randomized trials that compared shoe-based treatments (lateral heel wedge insoles or shoes with variable stiffness soles) aimed at reducing knee pain. They found 12 trials that met their criteria.
Researchers found the overall effect estimate was a standard mean difference in pain between interventions that showed a moderately significant effect of a lateral wedge in pain reduction. When trials were grouped according to the control group treatment, the authors found that compared with neutral inserts, lateral wedges had no association.