Acute Impact of Lower Body Positive Pressure Treadmill Walking in Individuals With Knee Osteoarthritis: A Pilot Study

The aim of the study was to determine acute symptomatic, gait, and biological effects of lower extremity loading during lower body positive pressure (lower body positive pressure) treadmill walking in individuals with knee osteoarthritis.

Participants with knee osteoarthritis ( N = 32) above the age of 50 performed two 45-min walking sessions at least 1 wk apart. Individuals walked at self-selected speed on the treadmill at 100% bodyweight or 50% bodyweight. The primary outcome was change in serum cartilage oligomeric matrix protein, with other outcome measures including change in knee joint pain, exercise intensity, gait parameters, and the concentration of other serum biomarkers of joint disease.

Across all time points, 50% bodyweight walking was associated with significant reductions in knee pain compared to 100% bodyweight ( P < 0.05 for all) with no significant difference in duration of moderate-intensity exercise. Fifty percent bodyweight was associated with significant decreases in cadence ( P < 0.001) and increased stride length ( P = 0.008). Biomarker analyses demonstrated 100% bodyweight walking was associated with a significant increase in cartilage oligomeric matrix protein at 45 mins compared to baseline ( P = 0.032), not observed with 50% bodyweight.

Fifty percent bodyweight walking in knee osteoarthritis using a lower body positive pressure treadmill acutely reduces joint pain, improves gait parameters, and does not increase markers of cartilage turnover. Future studies should investigate the longitudinal benefits of this rehabilitation approach.