Table 3.
COP sway (mean ± standard error) at baseline and during intervention in the control and nGVS groups and the results of two-way mixed-design ANOVA
| Value of COP sway measurement | Control group | nGVS group | ||||
|---|---|---|---|---|---|---|
| Baseline | Stimulation | P value | Baseline | Stimulation | P value | |
| RMS area (mm2) | 187.9 ± 17.2 | 182.2 ± 22.1 | 0.708 | 261.1 ± 41.2 | 244.9 ± 42.8 | 0.570 |
| Sway path length (mm) | 789.4 ± 65.2 | 790.3 ± 65.0 | 0.970 | 781.7 ± 59.2 | 714.3 ± 49.8 | 0.003 |
| ML mean velocity (mm/s) | 16.0 ± 1.3 | 16.1 ± 1.4 | 0.801 | 16.5 ± 1.3 | 14.9 ± 1.0 | 0.005 |
| AP mean velocity (mm/s) | 16.7 ± 1.5 | 16.6 ± 1.4 | 0.858 | 16.1 ± 1.5 | 14.5 ± 1.1 | 0.007 |
| Two-way mixed-design ANOVA | Time | Group | Time × Group | |||
| F value | P value | F value | P value | F value | P value | |
| RMS area | 0.479 (1,30) | 0.494 | 2.419 (1,30) | 0.130 | 0.111 (1,30) | 0.741 |
| Sway path length | 5.232 (1,30) | 0.029 | 0.249 (1,30) | 0.622 | 5.503 (1,30) | 0.026 |
| ML mean velocity | 3.882 (1,30) | 0.058 | 0.038 (1,30) | 0.847 | 5.549 (1,30) | 0.025 |
| AP mean velocity | 5.457 (1,30) | 0.026 | 0.476 (1,30) | 0.496 | 4.328 (1,30) | 0.046 |
COP sway is reported as mean ± standard error, AP anteroposterior; ANOVA analysis of variance, COP, centre of pressure, ML, mediolateral, nGVS, noisy galvanic vestibular stimulation, RMS root mean square