Skip to main content

Advertisement

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‡
  1. * p < .05.
  2. † p < .025.
  3. ‡ p < .0001.
  4. Tabulated values are averaged across subjects for each perturbation direction, and then averaged across directions in the final column except for the angles Acop and Aphi. Levels of significance are determined by a three-way ANOVA with display, subject, and direction as factors.