Wedge Insoles Useless for Back Pain

Frequent ads in the media, both print and electronic, promote the use of lateral wedge insoles as a treatment option for painful osteoarthritis of the knee. Do they work? According to Stephanie Watson, executive editor of the Harvard Women’s Health Watch, such insoles do little to relieve the pain of arthritis.

Medial knee osteoarthritis affects the inner part of the knee. Walking directs more force to the inside part of the knee (the medial aspect) than it does the outside part with the result that the medial compartment is where osteoarthritis usually appears first, according to Watson. Slightly tilting the foot is thought to reduce the load on the inner knee joint. That is why lateral insoles are thicker at the outer edge of the foot.

Watson reported that to learn if lateral wedge insoles actually relieve arthritis pain, an international team of researchers evaluated the results of 12 different shoe-based clinical trials that included a total of 885 participants. The trials compared the lateral wedge insole to a neutral insole and did not find a significant lessoning of pain. The findings echo new osteoarthritis treatment guidelines released by the American Academy of Orthopaedic Surgeons (AAOS) in May. Based on current research, the AAOS said it could not recommend lateral wedge insoles for people with medial knee osteoarthritis.

Nearly a third of Americans will develop osteoarthritis of the knee before age 70. With no “cure” beside knee replacement for this painful joint condition, relief has come from pain pills. Doctors have proscribed devices such as wedge insoles as a less drastic, side effect-free treatment option.

Robert Shmerling, M.D., clinical chief in the Division of Rheumatology at Beth Israel Deaconess Medical Center, and associate professor of medicine at Harvard Medical School tells his patients that they do not need to toss out lateral wedge insoles if they’ve worked for them, because everyone’s response to treatment can be different. “I think it makes sense to recommend insoles on a case-by-case basis, because even though the average response was no different between wedge insole users and non-users, individual response can vary, ” he said.

With the prices of wedge insoles ranging from $10 to $500, Shmerling advises his patients not to splurge on the costliest options first. “Considering the results of this study, I think it’s hard to justify a big investment in wedge insoles solely to treat knee pain from osteoarthritis, ” he said.

Watson noted that there is evidence that wearing flat-heeled, flexible shoes—especially ones that mimic the natural movement of walking barefoot—may do more to slow knee osteoarthritis than any insert a patient might place inside them.