Novel aquatic physiotherapy programme for elderly Chinese adults with osteoarthritis of the knee: a randomised controlled trial

Osteoarthritis of the knee is a chronic degenerative disease with a prevalence of 21·5–42·8% in China. Aquatic exercise has been used in rehabilitating patients with osteoarthritis of the knee, but its efficacy has been questioned with the outcomes of a recent meta-analysis. We aimed to assess the efficacy of a physiotherapist-designed aquatic exercise programme in reducing knee pain and physical impairments and improving functional mobility in a Chinese population with osteoarthritis of the knee.

This randomised, single-blinded, controlled trial was done at the Centre of Health and Wellness in Hong Kong and approved by the EdUHK Human Research Ethics Committee. After written informed consent was obtained, 83 eligible elderly participants (20 men and 63 women) were randomly assigned to either the aquatic exercise or control groups. The aquatic exercise group received aquatic exercise training for 1 h per week for 10 weeks along with advice on self-care. The control group received self-care advice only. Measurements were taken before and after the intervention. The primary outcome was knee pain as measured on a visual analogue scale. Secondary outcomes included passive flexion and extension ranges of motion (goniometry) and isometric muscle strength (hand-held dynamometry) of the affected knee and total distance covered in a 6 min walk test. We used two-way repeated-measures analysis of covariance to analyse the data.

The participants in the aquatic-exercise (n=31; mean age 56·2 years; SD 9·8 years) and control group (n=52; mean age 61·4 years; SD 10·7 years) were largely similar at baseline except that the knee-flexion range of motion was lowest in the participants within the aquatic-exercise group (p=0·008). The results of an intention-to-treat analysis revealed that knee pain was reduced exclusively in the aquatic-exercise group by 0·66 points (17·2%) at post-test measurements (F_1,79=4·253; p=0·042; η_p²=0·05; 95% CI 3·93–5·20). Knee-flexion range of motion in the aquatic-exercise group became similar to that of participants in the control group at post-test measurements (p=0·286; 95% CI −8·61 to 2·58). No group, time, or group-by-time interaction effects were noted in any other outcome variables. No adverse events were reported.

The aquatic exercise programme was safe and effective in reducing knee pain and improving knee-flexion mobility of elderly Chinese adults with osteoarthritis of the knee. Further studies comparing the effectiveness of aquatic and land-based physiotherapeutic exercises are warranted.

The Education University of Hong Kong (RG10/2012-2013R)