Pain management and strength gains compared between pneumatic partial weight support treadmill and underwater treadmill in overweight patients with knee osteoarthritis: A randomized controlled trial

OBJECTIVE: To investigate the efficacy of the pneumatic partial weight support treadmill compared to the underwater treadmill (UTM) for reducing pain and increasing quadriceps strength in overweight patients with knee osteoarthritis. DESIGN: Non-inferiority trial with a pre-specified 1-point range. METHODS: Participants (N = 109) were randomly assigned to the study (pneumatic partial weight support treadmill) (n = 55) or control (UTM) (n = 54) groups. Patients in both groups started with 50% weight support during the first week, 40% during the second week, and 30% during the third week and until the end of the study. Both groups received exercise for 30 min, 3 times per week for 8 weeks (24 sessions). Outcome measurements, including numerical pain rating scale, Western Ontario and McMaster Universities Osteoarthritis Index pain subscale, quadriceps strength, body weight, 6-min walking test, and quality of life, were evaluated at baseline, 8 weeks, and 12 weeks. RESULTS: Only 74 participants completed the study. Numerical pain rating scale and the Western Ontario and McMaster Universities Osteoarthritis Index showed non-inferiority of the study to control group. Improvement in quadriceps strength was significantly greater in the study than in control group. Adverse events were not significantly different between groups. Most subjects were satisfied and rated themselves as improved or much improved. Approximately three-quarters of participants attended more than 20 sessions, and there was no significant difference in outcomes between good and poor compliance. CONCLUSION: Pneumatic partial weight support treadmill can significantly decrease pain non-inferior to UTM, and can significantly increase quadriceps strength compared to UTM.