These Shoes Were Made for Walking

Knee osteoarthritis patients have improved knee loads when using specialized mobility shoe

(RxWiki News) When patients with knee osteoarthritis are walking, their knees may jut out to the side. Shoes that imitate barefoot walking can help with that.

A recently published study found that wearing a "mobility" shoe keeps the knee joint more aligned in knee osteoarthritis patients.

Using flat, flexible footwear can significantly reduce knee loading in patients with the joint condition, according to researchers.

"Change your walking shoes often."

Researchers, led by Najia Shakoor, MD, associate professor in the Section of Rheumatology at Rush Medical College, evaluated how different kinds of footwear affected knee loading in 12 patients with knee osteoarthritis.

When the knee loads during walking, the knee and leg start to take on a person's body weight.

In the study, participants wore their own preferred shoes for walking activities and the "mobility shoe," a flexible, lightweight shoe with specialized grooves that imitate barefoot walking.

Each of the patients walked barefoot, in their own shoes and in mobility shoes for at least six hours a day, six days a week at the start of the study.

Researchers measured participants' peak external knee adduction moment, or knee bend away from the center of the body, to get an idea of the knee's movements during the loading part of walking.

To measure gait, participants were instructed to walk at a self-selected normal speed and at 1 meter per second. The tests were repeated six, 12 and 24 weeks later.

The mobility shoes decreased knee adduction moment by 18 percent after 24 weeks compared to participants' own shoes, researchers found.

In addition, participants had an 11 percent and 10 percent reduction in knee adduction moment by week 24 when walking in their own shoes and when barefoot walking, respectively.

There were no differences in knee adduction between the mobility shoes and barefoot walking.

"[…] The current study demonstrates that not only were knee joint loads reduced while wearing the study mobility shoe, but…loads were reduced during natural barefoot gait and even improved when walking in the participants’ original footwear at six months; thus suggesting that this non-custom footwear functioned as a biomechanical training device to beneficially alter gait mechanics," researchers wrote in their report.

Researchers said it is unclear how long the shoes' effects would be maintained if use of the footwear was discontinued.

The participants' own footwear likely influenced their gait and it is also unclear how the mobility shoe specifically changed a person's gait.

In addition, the full extent of how much the mobility shoes reduced pressure, or loading, on the knees has not yet been determined. The reduction trend seemed to continue through the six-month study, researchers said.

Patients who revert back to their usual shoes could revert back to increased knee loading over time, according to researchers.

The authors noted that the number of people they studied was small and the data was gathered after only six months. Studies that cover a longer period of time are needed to see the shoes' effects over the long term.

The study, funded by the Arthritis Foundation, was published online April 10 in Arthritis & Rheumatism, a journal of the American College of Rheumatology.

Two of the authors were co-inventors of the shoe in the study. Rush University Medical Center owns the patent and will receive payment from its licensing agreement if it's successful. Some of the payments will go to the inventors.

Review Date: 
April 11, 2013