Evaluation of postural stability in patients wit unilateral vestibular hypofunction: effect of feet orientation

Abstract

ObjectiveTo investigate effect of feet orientation on the evaluation of the postural stability in patients with unilateral vestibular hypofunction (UVH) by timed standing tests and static posturography (SPG). Methods65 subjects with UVH and 92 healthy subjects regarded as control group took the postural stability tests in four different stances including(1) standard Romberg test, (2) feet–apart stance test, (3) tandem and (4) unilateral standing tests. In each stance, the postural stability was measured in both eyes open (EO) and eyes closed (EC) conditions. The average time that subjects kept balance before falling in each test conditions was recorded by stopwatch as the timed result. In addition, the sway velocity (SV) of center of foot pressure in the upright stance during standard Romberg test and feet apart stance, regarded as postural stability, was also recorded as SPG. Results(1) The balance–maintaining time of the UVH group in tandem and unilateral standing with EO and EC was decreased(P<0.001) compared with the control group. (2) The SVs during standard Romberg test and foot–apart stance with EO were not different between the UVH group and control group (P = 0.118 and 0.110 respectively), but significant with EC condition (P < 0.001). (3) For both groups, the SV during foot–apart standing was shorter than standard Romberg test both with EO and EC(P<0.05 and P < 0.001). (4) There was no correlation between the balance time and SV for either groups (P >0.05). ConclusionsThe results suggest that the tandem and unilateral stance tests may provide additional information about the upright stance to the SPG measurement in patients with UVH. The effect of feet orientation on SPG measurements should be considered.