Computerized Posturographic Measurement in Elderly Women with Unilateral Knee Osteoarthritis

OBJECTIVE To identify the subtle change of postural control in elderly patients with unilateral knee osteoarthritis (OA) with computerized dynamic posturography. METHOD Twenty-two healthy women and twenty-six women with unilateral knee OA, aged 60 and over, were enrolled. The computerized posturographic measures included a weight bearing pattern during squatting and sit-to-stand, sway velocity of center of gravity (COG) during one leg standing, on-axis velocity and directional control of COG during rhythmic weight shift, rising index during sit-to-stand, end sway during tandem walk, and movement time during step up/over. RESULTS It was shown that patients bore significantly less weight on the affected side during the 30° and 60° squat and sit-to-stand. Sway velocity of COG during one leg standing was greater whereas the on-axis velocity and directional control during the front/back rhythmic weight shift were significantly lower in the patient group. The rising index during sit-to-stand was significantly lower and movement time during step up/over with the affected side was significantly longer in patients. CONCLUSION This study demonstrated in detail a decline of postural balance by utilizing computerized posturography in elderly women with unilateral knee OA. They had less weight-bearing, more sway, and less ability of intentional postural control on the affected side.