Abstract
[Purpose] This study investigated the influence of exercise on an unstable surface on ROM of the knee, muscle strength and the physical function of patients with osteoarthritis of the knee. [Subjects] The subjects were 30 patients diagnosed with degenerative osteoarthritis of the knee, they were divided into an experimental group (n=15) and a control group (n=15). [Methods] The experimental group performed exercise using an aero step XL (TOGU, Germany) 3 times a week, for 6 weeks. A control group performed the same exercise on a stable surface and without aero step XL. [Results] After the intervention, the experimental group showed statistically significant improvements in active knee flexion, knee joint manual muscle test (MMT), knee joint MMT hamstring and WOMAC score. [Conclusion] Exercise on the unstable surface improved the symptoms of patient with osteoarthritis. Exercise on an unstable surface might be helpful for improving the muscle strength and alignment of lower extremities as well as improving physical function related to the knee joint.