A new study shows that both water-based (hydrotherapy) and traditional gym exercise programs can increase muscle strength and help people with osteoarthritis of the knee or hip walk faster and longer, which may reduce the risk of falls and disability.
In addition, the findings suggest that people with osteoarthritis may benefit from more intense exercise than currently recommended.
The results appear in the November issue of the Annals of Rheumatic Diseases.
Exercise Builds Strength
Researchers compared the effects of a six-week hydrotherapy or regular gym exercise program vs. no exercise at all in a group of about 100 people with osteoarthritis of the knee or hip.
Both of the exercise programs focused on resistance exercises designed to build muscle strength around the affected joint, and participants worked out three times a week either in the pool or in the gym.
Researchers found both exercise programs provided valuable benefits in improving physical function. Walking speed and distance improved significantly in both exercise groups compared with the non-exercisers.
The gym exercise program was slightly better at improving muscle strength. For example, the gym group also showed significant improvement in thigh muscle strength in both legs, but the hydrotherapy group only had improved strength in one leg.
Researchers say that because of the nature of hydrotherapy, the exercise intensity was not as high in the water-based group compared with the gym-based group, which might explain the differences in muscle strength.
Hydrotherapy May Offer Other Benefits
But one advantage of hydrotherapy is that it increases cardiovascular fitness and allows people with osteoarthritis to exercise to a greater degree of intensity without the harm that they would experience with a gym-based program. This may be especially important for people with severe forms of the disease.
"Patients with severe OA who find it painful to weight bear for extended periods may find that water provides the appropriate environment in which they can exercise at intensities that may confer significant health benefits," write researcher A. Foley of Flinders University Department of Rehabilitation and Aged Care in South Australia and colleagues.
Researchers also say that the intensity, volume, and frequency of exercise in the study were considerably higher than those recommended by the American Geriatrics Society for strength training in people with osteoarthritis. These findings suggest that higher intensity exercise may safely be prescribed for people with this potentially disabling disease.