Background - what is OA of the hip and what is exercise?
OA is a disease of the joints, such as your hip. When the joint loses cartilage, the bone grows to try to repair the damage. However, instead of making things better, the bone grows abnormally and makes things worse. For example, the bone can become misshapen and make the joint painful and unstable. Doctors used to think that osteoarthritis (OA) simply resulted in thinning of the cartilage. However, it is now known that OA is a disease of the whole joint.
OA is one of the most common forms of arthritis and affects men and women equally. OA is one of the main causes of disability as people grow older.
Exercise can be any activity that enhances or maintains muscle strength, physical fitness and overall health. People exercise for many different reasons including weight loss, strengthening muscles and to relieve the symptoms of OA.
This summary of an update of a Cochrane review presents what we know from research about the effect of exercise for people with OA of the hip. After searching for all relevant studies up to February 2013, we included five new studies since the last version of the review, giving 10 studies (549 participants) with mostly mild-to-moderate symptomatic hip OA, alone or with knee OA. Except for one study where participants enrolled in a tai chi programme, all other participants underwent land-based exercise programmes consisting of traditional muscle strengthening, functional training and aerobic fitness programmes, either individually supervised or as part of a group, compared with people who did not exercise.
Pain on a scale of 0 to 100 points (lower scores mean reduced pain):
- People who completed an exercise programme rated their pain to be 8 points lower (4 to 11 points lower) at end of treatment (8% absolute improvement) compared with people who did not exercise.
- People who completed an exercise programme rated their pain as 21 points.
- People who did not exercise rated their pain as 29 points.
Physical function on a scale of 0 to 100 points (lower score means better physical function):
- People who completed an exercise programme rated their physical function to be 7 points lower (1 to 12 points lower) at end of treatment (7% absolute improvement) compared with people who did not exercise.
- People who completed an exercise programme rated their physical function as 22 points.
- People who did not exercise rated their physical function as 29 points.
Quality of life (higher score means better quality of life):
- Overall, people with hip OA participating in the studies had a similar quality of life compared with the general population (normative scores of average 50 points), and quality of life was not further improved by participation in an exercise programme: 0 points higher.
- People who completed an exercise programme rated their quality of life as 50 points on a population norm-based scale.
- People who did not exercise rated their quality of life as 50 points on a population norm-based scale.
- three more people out of 100 dropped out of the exercise programme (1% absolute increase).
- Six out of 100 people in exercise programmes dropped out.
- Three out of 100 people who did not exercise dropped out.
Quality of the evidence
This review showed that there is high-quality evidence that in people with hip OA, exercise reduced pain slightly and improved physical function slightly. Further research is unlikely to change the estimate of these results.
Low-quality evidence indicated that exercise may not improve quality of life. Further research is likely to change the estimate of these results.
We do not have precise information about side effects such as injuries or falls during exercise, but we would expect these to be rare, and no injuries were reported in the studies.