Table 3 Demographics and baseline characteristics in the control, exercise, and exercise + whole-body vibration (WBV) groups
|  | Control (n = 201) | Exercise (n = 227) | Exercise + WBV (n = 127) | P-value |
|---|---|---|---|---|
Age (years) | 70.58 ± 6.22 | 69.40 ± 6.09 | 66.86 ± 6.55 |  < 0.001* |
Gender, n (%) | ||||
 Male | 82 (45.8) (40.8) | 56 (31.3) (24.7) | 41 (22.9) (32.3) | 0.002* |
 Female | 119 (31.6) (59.2) | 171 (45.5) (75.3) | 86 (22.9) (67.7) |  |
Body mass (kg) | 68.84 ± 12.40 | 69.28 ± 12.77 | 66.53 ± 13.52 | 0.138 |
BMI (kg/m2) | 28.09 ± 4.56 | 27.81 ± 4.87 | 26.74 ± 6.06 | 0.055 |
Side of affected knee, n (%) | ||||
 Left knee only | 35 (44.3) (17.4) | 32 (40.5) (14.1) | 12 (15.2) (9.4) | 0.080 |
 Right knee only | 42 (43.3) (20.9) | 37 (38.1) (16.3) | 18 (18.6) (14.2) |  |
 Bilateral knee | 124 (32.7) (61.7) | 158 (41.7) (69.6) | 97 (25.6) (76.4) |  |
KL grading, n (%) | ||||
 2 | 20 (43.5) (10.0) | 15 (32.6) (6.6) | 11 (23.9) (9.4) | 0.011* |
 3 | 82 (31.2) (40.8) | 111 (42.2) (48.9) | 70 (26.6) (59.8) |  |
 4 | 99 (41.9) (49.3) | 101 (42.8) (44.5) | 36 (15.3) (30.8) |  |
Pain duration (years) | 8.09 ± 3.76 | 7.60 ± 3.99 | 6.94 ± 4.04 | 0.035* |
Walking tolerance (min) | 30.20 ± 17.36 | 32.69 ± 17.25 | 37.95 ± 20.14 |  < 0.001* |
Alignment, n (%) | ||||
 Valgus | 13 (21.3) (6.5) | 37 (60.7) (16.3) | 11 (18.0) (8.7) | 0.010* |
 Varus | 114 (38.6) (56.7) | 107 (36.3) (47.1) | 74 (25.1) (58.3) |  |
 Neutral | 74 (37.2) (36.8) | 83 (41.7) (36.6) | 42 (21.1) (33.1) |  |