Mechanical unweighting effects on treadmill exercise and pain in elderly people with osteoarthritis of the knee

Abstract

Background and Purpose. People with osteoarthritis (OA) off the knee who have pain generally exhibited decreased activity and physical deconditioning. This study investigated the effects of mechanical unweighting on knee pain and exercise responses in people with OA of the knee who have pain. Subjects. Four men and 23 women, with a mean age of 67.9 years (SD=11.3, range=50-88) and having a 12-year average duration of knee OA, participated. Methods. A mechanical unloading device enabled subjects to perform a modified Naughton treadmill exercise test at 0%, 20%, and 40% of body weight support (BWS). Oxygen consumption (V̇O2), heart rate (HR), and perceived pain were measured during the last minute of each exercise stage. Results. Mechanical unweighting at 20% and 40% BWS decreased the V̇O2 and HR responses to treadmill exercise but did not decrease knee pain during walking in this sample. Conclusion and Discussion. These findings indicate that treadmill exercise accompanied by BWS permits recommended training intensities to be obtained in elderly people with OA, but may not provide pain relief in this group.