The SVM classifier detected symmetry index of single and double support time as being sensitive to distinguish between gait of patients with OA and healthy controls. This may suggest that symmetry gait measures may be used to evaluate patients with knee OA. In previous studies, gait alterations including gait asymmetry have been observed in patients with knee OA pre and post surgery [6]–[7][8], suggesting that an asymmetric gait pattern may be a subconscious compensation strategy to reduce the load in the operated limb. Therefore, asymmetric gait measures may be monitored after surgery to assess treatment outcome and recovery.