Comparison Of Static Postural Control Between Older Adults With And Without Knee Osteoarthritis

PURPOSE: This study compares static postural control during double-leg standing between older adults with and without knee osteoarthritis (KOA), under either eyes-open or eyes-closed conditions. METHODS: Fifteen older adults with KOA (7 females, age: 66.1 ± 2.6 years, height: 164.2 ± 6.6 cm, body mass: 64.6 ± 9.2 kg) and fifteen older adults without KOA (7 females, age: 65.3 ± 2.0 years, height: 166.3 ± 6.6 cm, body mass: 65.4 ± 8.2 kg) were recruited. Participants performed static balance by double-leg standing under eyes-open and eyes-closed conditions for at least 30 seconds. The center of pressure (COP) data was recorded at 1000 Hz using a force plate and filtered with a 10 Hz low-pass filter. COP variables included root mean square distance (RMS), average sway velocity in the anterior-posterior (AP) and mediolateral (ML) directions, and the area of the 95% confidence ellipse (95% area). Independent t-tests were employed to compare differences between the two groups, with a significance level set at 0.05. RESULTS: Compared to older adults without KOA, older adults with KOA had higher sway velocity in the AP (with: 197.3 ± 31.3 mm/s, without: 1763 ± 33.9 mm/s, p = 0.006) during double leg standing with eyes open. Moreover, older adults with KOA had also higher sway velocity in the AP (with: 495.9 ± 224.4 mm/s, without: 199.6 ± 32.5 mm/s, p = 0.050) and ML direction (with: 713.1 ± 224.3 mm/s, without: 230.3 ± 36.6 mm/s, p = 0.048), and larger 95% area (with: 422.0 ± 242.0 mm2, without: 236.8 ± 160.0 mm2, p < 0.001) during double-leg standing with eyes closed. CONCLUSIONS: Compared to older adults without KOA, older adults with KOA exhibited significantly impaired static postural control during double-leg standing, characterized by increased sway velocity and 95% area, particularly under the challenging eyes-closed condition.