Effects of light (<100 grams) finger tip touch on postural stability (gain-CoM displacement/surface displacement) during.01, .03, .10, .20, .40 Hz sinusoidal surface rotation in seven subjects with bilateral vestibular loss and seven age-matched control subjects (adapted with permission from Creath, et al, 2002). Fingertip touch reduces postural sway more in subjects with vestibular loss than controls and subjects with vestibular loss benefit most at high frequencies of surface rotation whereas controls benefit most at low frequencies.