EFFECTS OF AN EXERCISE PROGRAM WITH VIBRATING PLATFORM ON NEUROMUSCULAR PERFORMANCE AND POSTURAL CONTROL OF SEDENTARY OLDER ADULTS: RANDOMIZED CONTROLLED TRIAL
Vibration; Torque; Postural Control; Aging.
Introduction: Age related neuromuscular performance decline negatively affects functionality and contributes to frailty and disability in the elderly. The lack of interest and adherence to strength exercises ends up increasing the deficits in this population. Exercising on vibratory platforms have become a more viable alternative to potentiate the effects of the exercise. However, its benefits are still unclear. Objective: To analyze the effects of an 8-week exercise program on the vibratory platform on neuromuscular and functional lower limb performance and postural control of sedentary older adults. Methodology: This is a randomized controlled trial, with a blind evaluator, composed of 35 sedentary and healthy elderly men and women of both sexes (68.5 ± 2.6 years). All were initially submitted to evaluation of the isokinetic performance of knee extensors and plantar flexors, electromyographic activity of the Vastus Lateralis and soleus muscles, oscillation of the pressure center through baropodometry and lower limb function through Timed Up and Go test. After the initial evaluation the volunteers were randomly assigned to two groups: placebo (exercise with the platform off) and experimental group (exercise with the platform configured at a frequency of 50 Hz and peak-to-peak amplitude of 4 mm). Both participated in an exercise program on the platform, consisting of a bipodal isometric half-squat at 40º of knee flexion, with 4 sets of 1.5 min, with a rest interval of 1 minute. After the fourth and eighth weeks of training, the volunteers were submitted to the new evaluations, using the same procedures of the baseline evaluation. For analysis of the normality of the data, the Kolmogorov-Smirnov test was used and to attest the homogeneity between the groups a "t" test for independent samples was chosen. For intra and intergroup comparisons, a 2x3 mixed model ANOVA was used. Results: A reduction in the amplitude (p <0.01) and velocity (p = 0.01) of anteroposterior oscillation were observed for the experimental group after 8 weeks of training compared to the placebo group. Regarding the isokinetic performance, there was an increase in normalized peak torque and mean power in both groups, with no differences between them. No significant difference was observed in the electromyographic activity of the Vastus Lateralis and Soleus muscles nor in the TUG time. Conclusion: The 8-week exercise program on the vibratory platform promotes a reduction of postural oscillation in healthy elderly subjects. However, the improvement in isokinetic performance occurred due to the exercise performed, regardless of whether or not the platform was used.