Pool Therapy May Ease Arthritis

Experts surprised by results of gym versus water exercise

TUESDAY, Nov. 25, 2003 (HealthDayNews) -- Splashing in warm waters may have a curative effect for people with osteoarthritis.

Hydrotherapy, or water exercise in a heated pool, was found to improve strength and mobility in elderly patients with arthritis of the hip and knee, according to a study in the December issue of the Annals of the Rheumatic Diseases.

"The surprise in this study was that there was any functional gain in the hydro group," says lead author Maria Crotty, head of the Flinders University department of rehabilitation and aged care in Adelaide, Australia.

"We expected the patients would like hydro, but actually the gym group would get the gains. In fact, both exercise groups did pretty well, so it provides some support for hydro," she adds.

The gains were not huge, however.

"Overall, this is not an earth-shattering paper; these are modest improvements," says Dr. Stephen Honig, director of the Osteoporosis Center at the Hospital for Joint Diseases in New York City. "It's very hard to know what to make of this, other than there was some benefit in terms of quality of life and some muscle strengthening, which is good for patients who need to walk. It is also good as a pre-surgical intervention because the better the muscles are, the less difficulty you have with rehabilitation post-operatively."

Exercise often is recommended for people suffering from osteoarthritis, the most common form of arthritis and one in which the risk increases with increasing age and weight. While water exercise is extremely popular (and expensive), to date there has been little evidence in support of pool therapy, say the study authors.

To compare regular gym exercise with pool exercise, the authors enrolled 105 people aged 50 and over who had osteoarthritis of the hip or knee. The participants were divided randomly into one of three groups: one that exercised three times a week in a swimming pool with warm water, one that did an equivalent amount of exercise in a gym and one that did not exercise. For a six-week period, both the pool and the gym groups focused on resistance exercises.

At the end of six weeks, participants in both groups experienced similar improvements in walking speed and walking distance, while people in the group that did not exercise didn't change, the study reports.

The pool group had improved aerobic fitness, which benefits cardiovascular health. Muscle strength improved more in the gym group, however, with thigh muscle (quadriceps) strength improving in both legs. In the hydrotherapy group, muscle strength improved only in the left leg.

So how should the different exercises be used?

"Hydrotherapy is very useful with overweight patients who find aerobic exercise difficult (often they have painful knees and/or hips)," Crotty writes. "Osteoarthritis is a growing problem in overweight populations, and the common advice is [to]walk, but many of this patient group are reluctant or unable to walk."

If you want to focus on strengthening muscles, however, it's probably more efficient to use the gym, she adds.

In any event, the evidence is not thunderous. "What we have gotten out of this is that patients feel better and there is some evidence that muscle strength is better," Honig says. "People feel better, but they also feel better if they get into a hot tub."

More information

The Arthritis Foundation has more on exercise and arthritis and, specifically, on water exercise.

SOURCES: Maria Crotty, Ph.D., head, department of rehabilitation and aged care, Flinders University, Repatriation General Hospital, Adelaide, Australia; Stephen Honig, M.D., director, Osteoporosis Center, Hospital for Joint Diseases, New York City; December 2003 Annals of the Rheumatic Diseases
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