Overloaded or unevenly loaded knee joints can cause osteoarthritis (OA), or cause your OA to get worse. Learning how to walk differently may be able to correct the loading problem and reduce your knee pain. This approach is being studied in people with medial, or inner, compartment OA — which is 10 times more common than other forms of knee OA.
“The medial knee compartment bears a much higher load than the lateral [outside] compartment,” says Pete Shull, PhD, assistant professor in the School of Mechanical Engineering at Shanghai Jiao Tong University in Shanghai, China. “That’s just the way our bodies are structured. The inside knee compartment experiences loading [or force] that’s two to three times higher than the outside.”
Researchers are looking for ways to shift some of the medial compartment’s load to the lateral one. “The lateral compartment almost always has healthy cartilage,” says Shull. “The compartments are like brake pads on a bike, unevenly worn. So by changing the way someone walks, we can get the cartilage in the compartments to wear more evenly.”
What the Studies Show
In a 2011 study published in the Journal of Biomechanics, Shull and his colleagues retrained nine healthy people without osteoarthritis to shift their gait.
They had the participants walk on a treadmill while wearing equipment that measured the forces on the knee and gave feedback on how they were walking. With the feedback, participants were able to learn how to shift weight to different parts of the knee. The pressure on the medial compartment was reduced by 20%. A knee brace can reduce pressure by 10–15% and foot orthotics can reduce pressure by 5–10%.
Once Shull and his colleagues established that the technology could help healthy people learn new walking patterns, they decided to test it on people with symptomatic knee osteoarthritis.
The 2013 study published in the Journal of Orthopaedic Research, looked at 10 people with medial compartment knee OA and self-reported pain. They participated in weekly gait retraining sessions for six weeks. Their scores for pain and function improved by 29% and 32%, respectively.
Researchers at University of British Columbia and University of Melbourne have also been studying how changes in gait may lessen knee burden. In a 2012 study published in Arthritis Care and Research, they taught 22 participants with knee OA to shift their trunks toward their damaged knee. Although the greater the lean, the less pressure on the inner joint, participants had a tough time learning the new walk and initially at least, found no pain reduction.
Similarly, a 2013 study by the same group, which examined the effects of altering foot angles in 22 people with knee OA, showed no immediate change in knee pain or other symptoms.
What You Can Do Now
Shull and colleagues at Stanford University in California are working to develop wearable equipment to enable real-time feedback about gait patterns that can be used in clinics.
For now, patients can get movement retraining by working with a physical therapist, says orthopedic surgeon Jason Dragoo, MD, associate professor in the Department of Orthopedic Surgery at Stanford, who has been working with Shull and others on gait retraining research. “The physical therapist can help them to walk symmetrically and to spend equal time on both legs, making sure that the trunk is over the legs and not swaying side to side. When you limp, you lose efficiency and that can make knee pain worse.”
What’s most important is to practice the new movement, says Dr. Dragoo: “Once the physical therapist teaches you how to walk differently, you have to be committed to watching the way you walk.”