One of the major risk factors for getting or worsening osteoarthritis in the knee is overloading the joint. Some doctors may recommend weight loss or shoe inserts. Others may suggest a surgical joint realignment called high tibial osteotomy. But researchers are exploring a different approach that focuses on teaching patients to walk differently. 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, who began his research as a doctoral student at Stanford University.  “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 equipped to measure the forces on the knee.Then they asked the participants to walk again on the treadmill using something called haptic, or touch, feedback. The researchers placed small motor devices on the back of the participants’ legs and backs and instructed them to walk differently, either with their toes slightly in or out, or by shifting their upper body toward an aching knee.

“Whenever they took a step, they felt a buzz, like someone pressing on their back or legs,” explains Shull. “When they felt the buzz, they knew they were supposed to move in that direction.”

With the feedback, people walked in a new way within three to four minutes, as long as they still had the buzzes to remind them when they returned to walking in their old style. The pressure on the medial compartment lessened by 20 percent as compared to a knee brace, which reduced pressure by 10 to 15 percent, and foot orthotics, which reduced pressure by 5 to 10 percent.

Participants repeated lab training once a week for four weeks and practiced the new movement at home for 10 to 20 minutes a day. “We found that after four weeks, people were able to retain the new walking pattern,” says Shull. “After six weeks, people had less knee pain and more function and were still walking in the new way.”