Table 1.
Subjects’ characteristics and strength and balance performances.
| Young adults range = 18–34 years |
Middle-aged adults range = 44–59 years |
Elderly non-fallers range = 62–87 years |
Elderly fallers range = 64–89 years |
|
|---|---|---|---|---|
| Age, year | 24.1 ± 5.0 | 50.2 ± 4.5* | 75.5 ± 7.0*$ | 79.8 ± 6.7*$ |
| Body weight, kg | 72.5 ± 7.8 | 74.8 ± 16.3 | 63.6 ± 11.6$ | 63.7 ± 12.4$ |
| Height, cm | 180.4 ± 5.9 | 174.7 ± 8.8 | 164.0 ± 7.7*$ | 160.4 ± 8.6*$ |
| Body mass index (kg/m2) | 22.3 ± 2.2 | 24.6 ± 5.4 | 23.5 ± 3.4 | 24.7 ± 4.1 |
| PF MIT, N·m | 320.4 ± 64.7 | 235.4 ± 65.8* | 164.6 ± 63.2*$ | 105.5 ± 34.8*$† |
| PF nMIT, N·m·kg−1 | 4.4 ± 0.7 | 3.2 ± 0.7* | 2.5 ± 0.7*$ | 1.7 ± 0.5*$† |
| DF MIT, N·m | 89.6 ± 13.8 | 75.9 ± 20.2 | 57.7 ± 19.2 | 42.7 ± 9.9* |
| DF nMIT, N·m·kg−1 | 1.2 ± 0.1 | 1.0 ± 0.2 | 0.9 ± 0.2 | 0.7 ± 0.2* |
| PF + DF MIT, N·m | 410.0 ± 74.3 | 311.3 ± 72.7* | 222.2 ± 78.2*$ | 148.2 ± 40.3*$† |
| PF + DF nMIT, N·m·kg−1 | 5.6 ± 0.8 | 4.2 ± 0.7* | 3.4 ± 0.8*$ | 2.4 ± 0.6*$† |
| TCoP displacement, mm | 297.9 ± 80.8 | 344.3 ± 89.5 | 410.7 ± 137.5 | 744.0 ± 405.6*$† |
| nTCoP | 1.7 ± 0.4 | 2.0 ± 0.5 | 2.5 ± 0.8 | 4.7 ± 2.4*$† |
| XCoP displacement, mm | 167.0 ± 56.9 | 159.7 ± 34.8 | 227.2 ± 103.7 | 309.8 ± 152.3*$† |
| nXCoP | 0.9 ± 0.3 | 0.9 ± 0.2 | 1.4 ± 0.6 | 2.0 ± 0.9*$† |
| YCoP displacement, mm | 208.8 ± 61.0 | 271.5 ± 78.3 | 290.4 ± 91.5 | 576.5 ± 324.5*$† |
| nYCoP | 1.2 ± 0.3 | 1.6 ± 0.5 | 1.8 ± 0.5 | 3.6 ± 1.9*$† |
| EA, mm2 | 113.0 ± 50.8 | 123.4 ± 76.3 | 185.1 ± 100.9 | 279.6 ± 152.5*$† |
| nEA (EA/size), mm | 0.6 ± 0.3 | 0.7 ± 0.4 | 1.1 ± 0.6 | 1.7 ± 0.9*$† |
MIT: maximal isometric torque; nMIT : maximal isometric torque normalized for weight; PF: Plantar flexion; DF: Dorsal flexion; TCoP: center of pressure displacement; nTCoP: center of pressure displacement normalized for height; XCoP: Mediolateral center of pressure displacement; nXCoP: Mediolateral center of pressure displacement normalized for height; YCoP: Anteroposterior center of pressure displacement; nYCoP: Anteroposterior center of pressure displacement normalized for height; EA: 95% Ellipse area of the center of pressure displacement; nEA: 95% Ellipse area of the center of pressure displacement normalized for height. Value are means ± SD. *Significant difference from young subjects, P < 0.05. $ Significant difference from middle-aged group, P < 0.05. † Significant difference from elderly non-fallers, P < 0.05.