Efeitos do exercício de vibração de corpo inteiro na atividade neuromuscular de membros inferiores de pacientes com lúpus eritematoso sistêmico e comprometimento de massa óssea

Abstract

Glucocorticoid induced osteoporosis (GIOP) is one of the most important causes of morbidity in systemic lupus erythematosus (SLE). Whole body vibration exercises (WBVE) may be a safe alternative to prevent and amend bone damage, and may decrease muscle related risk factors for falls, especially in a group of individuals that should not be sun exposed. It is possible to evaluate neuromuscular responses to mechanical vibrations through surface electromyography of the muscles (sEMG), and this way define the most effective protocol of these exercises. The main objective was to analyze and compare the acute responses on sEMG of lower limbs of female lupus individuals and chronic glucocorticoid use with and without bone impairments and healthy controls while being submitted to mechanical vibrations. All the patients had a dual-energy x-ray absorptiometry (DXA) scans for body composition, which evaluated right hip, lumbar segment and whole body. After DXA they were divided in three groups. Twenty-seven women were submitted to WBVE, on different frequencies and same amplitude. The experiment was performed in two days, 48h apart. The patients stood on half squat position on a vertical oscillating/vibratory platform at different exposure frequencies (30, 40 and 50 Hz), named conditions, and same amplitude ("low") in both days. The peak acceleration (apeak) was measured with an accelerometer. It was obtained vastus lateralis (VL), gastrocnemius medialis (GM) and tibialis anterioris (TA) sEMG analysis simultaneously while performing the exercises, in a randomized manner. All the individuals were able to perform the protocol, which was proven to be safe. It was demonstrated that most were overweight or obese in body composition evaluation. There was no differences between sarcopenia index among groups, despite the bone impairment. The greatest muscle activation occurred in the lower frequency applied for VL. It was found group x frequency difference only for GM (p= 0.034; η2=0.272). WBVE demonstrated to be a safe and viable physical exercise for lupus population with chronic glucocorticoid. The results of this study suggest that they may have similar neuromuscular activity to healthy controls, so the protocols may be similar to same age and sex.