A small adjustment to one’s walking style can ease osteoarthritis pain as effectively as medication and delay the need for knee surgery by years, according to a new study.
Osteoarthritis, a degenerative joint disease, affects nearly a quarter of adults and is a leading cause of disability worldwide.
It occurs when the cartilage cushioning the ends of bones wears down, leading to pain, stiffness, and reduced mobility.
There is currently no way to reverse this damage, with treatment largely limited to pain management through medication and, eventually, joint replacement.
Now, researchers at the University of Utah say that gait retraining may offer a non-pharmacological alternative.
In a year-long clinical trial, they found that making small adjustments to the angle of the foot while walking provided pain relief equivalent to medication.
The study, published in The Lancet Rheumatology, also showed that gait retraining reduced knee cartilage degradation.
“We have known that for people with osteoarthritis, higher loads in their knee accelerate progression and that changing the foot angle can reduce knee load,” Scott Uhlrich, an author of the study, said. “So the idea of a biomechanical intervention is not new but there have not been randomised, placebo-controlled studies to show that they’re effective.”
Researchers focused on patients with mild-to-moderate osteoarthritis in the medial compartment of the knee, the inner side of the joint, which typically bears more weight than the outer, lateral compartment.
In this form of the disease, the optimal foot angle for reducing stress on the medial compartment varies from person to person, depending on their natural gait and how it shifts when they adopt the new walking pattern.
“We used a personalised approach to selecting each individual’s new walking pattern, which improved how much individuals could offload their knee and likely contributed to the positive effect on pain and cartilage that we saw,” Dr Uhlrich said.
During their first two visits, participants underwent a baseline MRI and practised walking on a pressure-sensitive treadmill while motion-capture cameras recorded their gait mechanics.
Researchers then analysed the data to determine whether turning a participant’s toe inward or outward would best reduce knee loading, and whether a 5-degree or 10-degree adjustment would be most effective.
Those unlikely to benefit, such as participants whose knee loading did not decrease with any adjustment, were excluded.
Of the 68 participants, half were randomly assigned to a dummy treatment group to control for the placebo effect.
The intervention group was prescribed a specific foot angle change that maximally reduced their knee loading.
Both groups took part in six weekly training sessions.
Participants in the intervention group received real-time feedback via vibrations from a device worn on the shin, helping them maintain the prescribed foot angle.
After training, they were encouraged to practise their new gait for at least 20 minutes a day until it became natural, supported by periodic check-in visits.
One year later, participants reported on their knee pain and underwent a second MRI to quantitatively assess cartilage damage. Those in the intervention group experienced reduced pain and showed less cartilage degradation compared with the control group.
“With the MRIs, we also saw slower degradation of a marker of cartilage health in the intervention group, which was quite exciting,” Dr Uhlrich said.
“The reported decrease in pain over the placebo group was somewhere between what you’d expect from an over-the-counter medication, like ibuprofen, and a narcotic, like OxyContin.”
One of the key advantages of the method, according to scientists, is the potential for participants to adhere to the intervention over long periods.
“Especially for people in their 30’s, 40’s, or 50’s, osteoarthritis could mean decades of pain management before they’re recommended for a joint replacement,” Dr Uhrlich said.
“This intervention could help fill that large treatment gap.”
Researchers hope to streamline the gait retraining process before deploying the treatment clinically.
“We and others have developed technology that could be used to both personalise and deliver this intervention in a clinical setting using mobile sensors, like smartphone video and a ‘smart shoe’,” Dr Uhlrich said.
