Comparing the efficacy of aquatic exercises and land-based exercises for patients with knee osteoarthritis

Aims: The study aims to compare changes over time among three study groups on the primary outcome, pain, as well as on the secondary outcomes, other symptoms, activities of daily living function, sport and recreation function, knee-related quality of life, knee range of motions and the six-minute walk test and to investigate whether aquatic exercises would be superior compared with land exercise on pain reduction.

Background: Osteoarthritis is a prevalent musculoskeletal disorder. Appropriate exercise may prevent osteoarthritis-associated disabilities and increase life quality. To date, research that compares the effects of different types of exercise for knee osteoarthritis has been limited.

Design: The study is a randomised trial.

Methods: Eighty-four participants with knee osteoarthritis were recruited from local community centres. Participants were randomly assigned to the control, aquatic or land-based exercise group. Exercise in both groups ran for 60 minutes, three times a week for 12 weeks. Data were collected at baseline, week 6 and week 12 during 2006-2007. The instruments included the Knee Injury and Osteoarthritis Outcome Score, a standard plastic goniometer and the six-minute walk test. Generalised estimation equations were used to compare changes over time among groups for key outcomes.

Results: Results showed statistically significant group-by-time interactions in pain, symptoms, sport/recreation and knee-related quality of life dimensions of Knee Injury and Osteoarthritis Outcome Score, knee range of motions and the six-minute walk test. However, the aquatic group did not show any significant difference from the land group at both weeks 12 and 6.

Conclusions: Both aquatic and land-based exercise programmes are effective in reducing pain, improving knee range of motions, six-minute walk test and knee-related quality of life in people with knee osteoarthritis. The aquatic exercise is not superior to land-based exercise in pain reduction.

Relevance to clinical practice: Similar outcomes could be possible with the two programmes. Health care professionals may consider suggesting well-designed aquatic or land-based exercise classes for patients with osteoarthritis, based on their preferences and convenience.