Table 3.
Summary of balance-perturbation test results; paired t-test*= p<0.05; two-way repeated-measures ANOVA** p<0.05; NBOS=Normal base-of-support; WBOS=Widened base-of-support
| Trial type | Frequency of responses | Mean±SD
|
p value | ||
|---|---|---|---|---|---|
| NBOS | WBOS | ||||
| Unconstrained (react naturally) | Stance | No step | 3.6±12.5 | 6.8±24.9 | 0.35 |
| Crossover step | 12.5±21.3 | 15.1±22.6 | 0.43 | ||
| Side-step-sequence | 50.0±44.2 | 36.5±40.1 | 0.23 | ||
| Multiple steps | 4.7±10.5 | 11.5±21.1 | 0.25 | ||
| Arm movement | 8.3±13.9 | 7.3±17.2 | 0.84 | ||
| Limb collisions | 19.3±29.3 | 13.0±20.4 | 0.39 | ||
|
| |||||
| Walk-in-place | No step | 0.0 | 0.0 | - | |
| Crossover step | 33.3±39.4 | 37.5±35.2 | 0.51 | ||
| Side-step-sequence | 42.7±37.0 | 32.3±27.5 | 0.24 | ||
| Multiple steps | 34.4±29.5 | 39.6±33.8 | 0.49 | ||
| Arm movement | 26.0±25.8 | 21.9±32.6 | 0.70 | ||
| Limb collisions | 20.8±25.5 | 21.9±27.0 | 0.89 | ||
|
| |||||
| Constrained (try not to step) | No step, Perturbation, m/s2 | 1.0 | 68.8±38.2 | 89.1±22.3 | 0.002** |
| 1.5 | 35.9±34.1 | 60.9±40.8 | |||
| 2.0 | 4.7±10.1 | 15.6±30.1 | |||
| 2.5 | 0.0 | 1.6±6.3 | |||
| 3.0 | 0.0 | 0.0 | |||
|
| |||||
| Cued forward-step | Extra lateral steps | 13.8±17.5 | 3.8±8.1 | 0.04* | |