Lower Positive Body Pressure Walking Significantly Improves Pain And Function In Individuals With Knee Osteoarthritis

OBJECTIVES: Body weight-supported (BWS) walking therapies, lower body positive pressure (LBPP) treadmills or aquatic pool walking could provide a treatment to reduce pain in individuals with knee osteoarthritis (OA). Our objective was to examine the potential benefits of BWS for individuals with knee OA. DESIGN: Parallel group randomized clinical trial. Forty-nine (n=49) participants, aged>50 with knee OA, randomly assigned to one of three groups: (1)Control (n=16), (2)Aquatic (n=17), and (3)LBPP (n=16). Interventional groups had two 30-minute walking sessions for eight weeks. The control group received no active treatment. Primary outcome was change in Knee Injury and Osteoarthritis Outcome Score (KOOS)-Pain from baseline to 8 weeks. Secondary outcomes included other KOOS subscales, six-minute walk test (6-MWT), joint kinematics, and serum cytokine concentration. RESULTS: Forty-one participants completed the trial. Changes in KOOS-Pain from baseline to 8 weeks were statistically significant and clinically relevant in the LBPP group (15.3,95% CI 5.0,25.6). Changes in the other groups were not statistically significant (Aquatic 0.9(95% CI -7.8,9.6); and Control -3.3(95% CI -12.3,5.7). Post-hoc analyses indicated improvements were significantly larger with LBPP. This group improved in 6-MWT(58.9m, 95% CI 26.1,91.7) and most KOOS sub-scales. Improvements in KOOS-Pain at 8 weeks in the LBPP group were associated with increased knee flexion(P=0.02). Only the control group had significant increases in IL-1β(P=0.04) and IL-1RA(P=0.02) concentration at 8 weeks. CONCLUSIONS: This is the first randomized controlled trial of BWS for knee OA and showed benefits of LBPP treadmill walking. Future, larger studies should assess effect size, sustained benefits and cost-effectiveness.