Efeitos agudos da plataforma vibratória no desempenho neuromuscular dos membros inferiores de idosos: ensaio controlado, randomizado e cego

Abstract

Background: Elderly people tend to present a decrease of the trophism, amplitude of muscular activation and strength, which causes significant negative implications in their functionality. Studies about exercise on the whole body vibration have been performed, however, there is a lack in the literature regarding the possible neurophysiological acute effects of this technique in elderly people. Objective: To analyze the immediate effects of an exercise session on the vibratory platform on the lower limb neuromuscular performance of elderly. Methods: This is a ramdomized, blind, controlled trial, in wich 44 volunteers, of both genders, mean age of 68,5 ± 2,67 years, were submitted to an evaluation of the postural oscillation (baropodometry), isocinetic performance and electromyographic activity of the vastus lateralis (VL) and soleus muscle of the dominant limb. After, they were randomly assigned in two groups, with 22 participants each: placebo group (PG) – underwent a series of exercises with the vibrating platform off; and experimental group (EG) - underwent a series of exercises with the vibrating platform on, configured at frequency of 40 Hz and a displacement amplitude of 4 mm. Both groups executed the same exercise protocol in the platform, composed of a bipodal isometric squat at 400 of knee flexion, being 4 series of 90 seconds of duration, with interval of 1 minute. At the end of the intervention, the volunteers were submitted to a re-evaluation identical to the previous performed before the exercise protocol. Data were analyzed using SPSS 21.0 software, assigning a level of significance of 5% (p ≤ 0,05). To the analysis of normality of data it was used the Kolmogorov-Smirnov test and to attest the homogeneity between groups, a paired-sample test t. To analyze the differences between and within group, it was used a mixed model ANOVA. Results: There was a significant between-group increase in RMS for the VL and within group for soleus RMS after the intervention protocol in the EG. For isokinetic performance, there was an within group increase in peak torque of knee extensors on EG and of plantar flexors on PG and EG; for the variable power, there was an within group increase in both groups. It was not observed significant differences on postural oscillation. Conclusion: The protocol of exercise on the whole-body vibration promotes a greater neuromuscular recruitment of VL muscles in elderly. However, it was not observed immediate effects on postural oscillation or in isokinetic performance in this population.