Table 3 Significant differences in various parameters due to activation of vibrotactile display
From: Biofeedback improves postural control recovery from multi-axis discrete perturbations
Perturbation direction (deg) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Display | 0 | 11 | 45 | 90 | 180 | 191 | 225 | 270 | Mean | |
COP Measures | ||||||||||
Time to peak deflection (Tcop, in ms) | OFF | 372 | 361 | 366 | 391 | 369 | 361 | 361 | 388 | 371 |
ON | 380 | 378 | 367 | 408 | 384 | 361 | 368 | 398 | 381 | |
Mag. of peak deflection (Rmax, in mm) | OFF | 67.3 | 63.0 | 71.4 | 83.5 | 68.6 | 70.8 | 78.8 | 80.8 | 73.0 |
ON | 68.3 | 68.8 | 75.8 | 84.0 | 72.7 | 71.9 | 79.2 | 84.7 | 75.7* | |
Angle of peak deflection (Acop, in deg) | OFF | −179 | −166 | −125 | −92.0 | 1.16 | 13.1 | 50.1 | 94.1 | N/A |
ON | −180 | −165 | −128 | −87.2 | −0.17 | 13.8 | 49.4 | 93.7 | N/A | |
RMS of magnitude (Rrms, in mm) | OFF | 14.0 | 17.9 | 15.7 | 20.9 | 12.9 | 13.6 | 16.6 | 15.6 | 15.9 |
ON | 15.4 | 15.1 | 14.1 | 15.4 | 16.4 | 16.7 | 15.1 | 16.7 | 15.6 | |
Tilt Measures | ||||||||||
Time to peak tilt (Tphi, in ms) | OFF | 576 | 568 | 519 | 153 | 524 | 530 | 488 | 552 | 536 |
ON | 512 | 498 | 493 | 520 | 531 | 513 | 491 | 503 | 508* | |
Mag of peak tilt (phimax, in deg) | OFF | 4.35 | 4.80 | 2.99 | 3.50 | 7.39 | 6.41 | 4.67 | 3.02 | 4.64 |
ON | 4.56 | 4.03 | 2.70 | 2.93 | 7.15 | 6.51 | 4.72 | 2.85 | 4.43 | |
Angle of peak deflection (Aphi, in deg) | OFF | −174 | −171 | −122 | −52.3 | −3.90 | −0.92 | 15.6 | 57.6 | N/A |
ON | −174 | −169 | −126 | −60.1 | −3.16 | −0.77 | 18.7 | 81.6 | N/A | |
Max. recovery velocity (Vmax, in deg/s) | OFF | 10.5 | 12.1 | 6.93 | 6.31 | 15.4 | 13.0 | 10.7 | 6.52 | 10.2 |
ON | 14.6 | 13.4 | 7.31 | 7.13 | 17.6 | 14.9 | 12.6 | 7.22 | 11.9† | |
Time of max. velocity (Tvel, in s) | OFF | 0.81 | 0.76 | 0.77 | 1.00 | 0.73 | 0.75 | 0.63 | 0.95 | 0.80 |
ON | 0.75 | 0.70 | 0.73 | 0.76 | 0.74 | 0.73 | 0.67 | 0.72 | 0.72† | |
Recovery time (Trec, in s) | OFF | 1.42 | 2.89 | 2.19 | 1.49 | 3.01 | 3.09 | 2.50 | 1.93 | 2.31 |
ON | 1.16 | 1.28 | 1.49 | 1.36 | 1.61 | 1.43 | 1.19 | 1.38 | 1.36‡ | |
RMS of magnitude (phirms, in deg) | OFF | 1.05 | 1.59 | 1.06 | 0.86 | 1.16 | 1.33 | 1.04 | 0.99 | 1.13 |
ON | 0.92 | 0.87 | 0.85 | 0.77 | 0.92 | 1.01 | 0.83 | 0.79 | 0.87‡ | |
Pct. of time in dead zone (pct0) | OFF | 57.2 | 45.5 | 52.6 | 67.9 | 49.7 | 44.1 | 53.2 | 57.8 | 53.5 |
ON | 72.5 | 76.5 | 73.7 | 83.6 | 73.9 | 66.5 | 76.5 | 79.0 | 75.3‡ | |