A new Cochrane review finds that exercise may improve pain and function, but the benefits may fall short of what patients would notice in daily life.

Hip osteoarthritis is a condition affecting millions of people worldwide and a leading cause of chronic pain and disability. Exercise is widely recommended as a first-line treatment for managing hip arthritis pain.

Led by researchers from University of Sydney and University of Melbourne, the findings show exercise produces small improvements in pain and physical function for people with hip osteoarthritis, but those improvements may not be large enough to make a meaningful difference to patients.

The review included 18 clinical trials involving 1,368 people. Participants were mostly women (63%) and were aged between 53 and 74 years, meaning findings may not apply to younger people. Exercise programmes in the included studies varied widely, lasting between two and 52 weeks and covering a range of types including strengthening, aerobic, and mind-body approaches.

Compared with no treatment or usual care, exercise probably reduces pain by around 7 points on a 100-point scale. However, experts generally consider an improvement of at least 12 points necessary for patients to notice a meaningful difference in daily life. Physical function showed a similar pattern. The authors note, however, that these thresholds were derived largely from knee and mixed osteoarthritis populations, and may not entirely reflect the hip osteoarthritis experience.

Quality of life, arguably the outcome patients care about most, showed little to no improvement with exercise regardless of the comparison used.
 

"Exercise is recommended as a primary treatment for hip osteoarthritis, and this review doesn't overturn that, but it does suggest we should be honest with patients that the average benefit may be modest, and that we need better-designed trials to understand who benefits most and from which type of exercise."

— Michelle Hall, co-lead author from the University of Sydney. 

This update analysed results differently from its 2014 predecessor, which pooled all available data together and found high-quality evidence that exercise slightly reduced pain. The new review separated trials according to what exercise was being compared against.

When exercise was tested against a placebo or sham treatment, the evidence for pain relief weakened considerably. And adding exercise on top of another treatment made little difference either. While no single type of exercise came out on top, the authors caution that the evidence to answer that question properly simply isn't there yet.

The review stops short of saying exercise is ineffective or should be abandoned as a recommendation. Exercise carries broad health benefits beyond arthritis, is low-cost, and is unlikely to cause harm. 

Most studies included in this review were small and unblinded, which may have influenced outcomes. Because pain and function were largely self-reported, and participants knew whether they were exercising, exercise may appear more effective than it truly is.

The authors call for larger, better-designed trials to give patients and clinicians a clearer picture of what exercise can realistically achieve for hip osteoarthritis specifically.
 

“There just isn’t a huge body of evidence out there. For some people struggling with hip pain, exercise can really be their only hope, but I also don’t want to give patients false hope. It’s important future research is done with larger, better-quality trials, examining what types of exercise work specifically for different people.” 

— Belinda Lawford, co-lead author from the University of Melbourne. 

Read the review