A new study published Wednesday in Arthritis & Rheumatology found that walking for exercise could help stave off new knee pain in people with osteoarthritis, Dani Blum writes for the New York Times.

Slide deck: Musculoskeletal health trends

Study details and key findings

According to CDC, osteoarthritis, often referred to as "wear and tear" arthritis, affects more than 32.5 million adults in the United States alone. It occurs when an individual's joint cartilage deteriorates, and the underlying bone starts to change.

Notably, the risk of developing knee osteoarthritis increases with age, and roughly one-third of people over 60 have the condition, according to lead study author Grace Hsiao-Wei Lo, who serves as an assistant professor at Baylor College of Medicine.

For the study, which began in 2004, researchers surveyed 1,212 individuals ages 50 or older with knee osteoarthritis—the most common form of arthritis in the United States.

Researchers assessed participants' baseline knee pain with radiographs to evaluate their conditions. Then, they asked participants to record their exercise habits and later reviewed any symptoms at follow-up appointments to gauge the frequency of their knee pain.

While some participants experienced persistent knee pain at the outset, others did not. After four years, those who did not initially have frequent knee pain and walked for exercise were less likely to experience new, regular episodes of stiffness or aches around their knees and had less structural damage in their knees, the New York Times reports.

However, after four years, 37% of the participants who did not walk for exercise developed new, frequent knee pain, compared with 26% who regularly walked for exercise.

Commentary

While many patients take over-the-counter medications like ibuprofen or naproxen to treat osteoarthritis, these treatments can lead to kidney issues and ulcers when taken in in large doses.

The study's findings represent "a paradigm shift," Lo said. "Everyone's always looking for some kind of drug. This highlights the importance and likelihood that interventions for osteoarthritis might be something different, including good old exercise." 

However, the study's researchers cannot definitively prove that walking helped prevent new knee pain, and it did not seem to ease existing knee pain, Blum writes. Still, the results support clinicians' current understanding of how best to manage the condition.

According to Elaine Husni, a rheumatologist at Cleveland Clinic who was not involved in the study, regular movement can help build muscle mass, while strengthening ligaments around the joints that have osteoarthritis. Walking is a low-intensity, low-impact exercise that allows people to maintain the strength and flexibility that are necessary for healthy joints, she added.

"It's an intervention that anyone can do," Husni said. "You have no excuse. You can do it anywhere you are."

For those who are already in pain, they should try not to overexercise, said Justen Elbayar, a sports medicine specialist in the department of orthopedic surgery at NYU Langone Health who was not involved in the study.

In some patients with severe arthritis, long-distance walking could further exacerbate existing aches and pains. However, for those with less severe arthritis, "it's one of the best exercises you can do," he said.

To ward off osteoarthritis with this regimen, Elbayar recommends starting with short, easy walks and gradually building up difficulty over time.

Ultimately, Elbayar said that "[t]he goal of the exercise is to provide muscular support to an arthritic knee … and to let the joints, tendons and tissues become acclimated to the walking," Blum writes.

Even though a simple walk down the street will not repair cartilage or get rid of existing pain, the exercise regimen offers a more accessible option for mitigating some of the more intrusive aspects of the condition, Lo noted, especially since "walking doesn't cost a cent." (Blum, New York Times, 6/8; Lo et al., Arthritis & Rheumatology, 6/8)