ABSTRACT
OBJECTIVE: This study investigated the acute residual effects induced by different frequencies of whole-body vibration (WBV) on postural control of elderly women. DESIGN: Thirty physically active elderly women (67 ± 5 years) were randomly divided into three groups: two experimental groups (high WBV frequency: 45 Hz and 4 mm amplitude, n = 10; low WBV frequency: 30 Hz and 4 mm amplitude, n = 10) and one control group (n = 10), with no treatment. The participants were first subjected to stabilometry tests and were then guided through three sets of isometric partial squats for 60 s while the WBV stimulation was applied. The control group was subjected to the same conditions but without the WBV stimulation. The participants were again subjected to body balance tests immediately following the end of the intervention period and again at 8, 16, and 24 min. To measure body sway control, three 60 s tests were performed at 10 s intervals for each of the following experimental conditions: (1) eyes opened and (2) eyes closed. The following variables were investigated: the average velocity of the displacement of the centre of pressure in the anterior-posterior and medial-lateral planes as well as in the elliptical area. RESULTS: A 3 (condition) × 5 (test) two-way repeated-measures ANOVA did not identify significant differences in the stabilometric variables, regardless of group, time, or experimental condition. CONCLUSIONS: The effect of WBV, regardless of the stimulation frequency, did not have a significant effect immediately after or up to 24 minutes after vibration cessation, on the variables involved in the control of postural stability in physically active elderly women.
