Bring Out the Flip-Flops and Sneakers, Better for Osteoarthritis
Just in time for summer, you can bring out your flip-flops and sneakers and feel confident that they are better for your knees and may help prevent osteoarthritis. That’s the word from researchers at Rush University Medical Center.
Some people worry about the lack of arch support characteristic of flip-flops and sneakers with flexible soles. However, it turns out that footwear designed to provide the feet with lots of support have largely neglected the biomechanical impact on the legs, according to rheumatologist Najia Shakoor, MD, the main author of the new study.
A key risk factor for development of osteoarthritis, which affects approximately 27 million people in the United States alone, is loading on the knee joints. People’s choice of footwear has a significant impact on that load, especially when they walk. The new Rush University study found that “flat, flexible footwear significantly reduces the load on the knee joints compared with supportive, stable shoes with less flexible soles.”
Osteoarthritis most often affects the weight-bearing joints of the knees, hips, and lower back, according to the Arthritis Foundation. Osteoarthritis of the knees is associated with pain when walking, climbing stairs, and rising from a chair. The pain can prevent patients from exercising the legs and can result in weakened thigh muscles, which further debilitates the patient.
Osteoarthritis of the hips is associated with pain in the buttock, inner thigh, and groin, referred pain in the knee and side of the thigh, and limping when walking. Spinal osteoarthritis is characterized by a breakdown of the spinal discs, stiffness and pain in the neck and lower back, pinched nerves in the back, and weakness or numbness in arms and legs due to pinched nerves.
In the new study, the researchers evaluated the gait of 31 patients who had symptoms of osteoarthritis. The patients’ gait was analyzed while they walked barefoot and while wearing four different types of shoes: clogs, stability shoes (prescribed for comfort and stability), a flat athletic shoe with flexible soles, and flip-flops.
The loads on the knee joints were 11 to 15 percent higher when people wore the clogs and stability shoes when compared with the flexible-soled sneakers, flip-flops, or barefoot. Shakoor noted that the reduction in joint load seen with the flat shoes and barefeet was comparable to that seen with wedged orthotic shoe inserts and knee braces, which are used to reduce the load on knee joints in people who have osteoarthritis.
Shakoor noted that clogs and stability shoes have a heel, which produces greater load on the knees. The reduced joint load associated with the flip-flops and flexible-soled sneakers is likely associated with the fact that, like walking barefoot, they allow the foot to flex naturally when it contacts the ground, which reduces the impact on the knee joint.
Although the results of this study suggest that flip-flops and flexible-soled athletic shoes reduce the impact on the knees and can thus reduce the risk of osteoarthritis or help those who have the disease, this choice of footwear is not for everyone. Shakoor warned that flip-flops could be hazardous for elderly, frail, and unstable individuals because they are too loose-fitting and could contribute to falls.
Rush University Medical Center, news release Mar. 24, 2010