Aquatic versus land-based exercise for knee osteoarthritis: a randomized controlled trial

Whether land- or aquatic-based rehabilitation is more effective in improving knee osteoarthritis (OA) is still unclear. This study assessed the effectiveness of aquatic-based treatments in patients with knee OA.

The participants were divided into a land-based exercise group (G1, n=30) and a water-based exercise group (G2, n=30). The exercises were performed for 8 weeks. The primary endpoint was a response to physical therapy, defined as a 20% decrease in the summed score for the Western Ontario and McMaster Universities-Osteoarthritis Index (WOMAC) pain subscale from T1 (before the start of the rehabilitation program) to T2 (8 weeks later). The secondary endpoints included the Visual Analog Scale (VAS) for pain, WOMAC functional and stiffness subscales, Lequesne Index, and Medical Outcome Study Short Form (SF-12) for physical and mental health.

A 20% decrease in the summed WOMAC pain subscale score was noted in 33% of patients in G1 (n=10) and 93% in G2 (n=28) (P<0.001). VAS scores at walking decreased by 14% in G1 vs. 37% in G2 (P<0.001), WOMAC stiffness subscale decreased by 18% in G1 vs. 53% in G2 (P<0.001), and the Lequesne index decreased by 10% in G1 vs. 33% in G2 (P<0.001). Quality of life improvement was greater in G2 than in G1; SF-12 (physical) increased by 2.3 in G1 vs. 5.4 in G2 (P=0.023), and SF-12 (mental) increased by 6.3 in G1 vs. 10.9 in G2 (P=0.022).

Both aquatic and land-based exercises improved pain intensity, functional impairment, degree of handicap, and quality of life impairment caused by OA. However, the improvement was more significant in the aquatic-based exercises group.