## 4 Discussion  
Following the results of muscle activity secondary to WBVE measured by sEMG in SLE individuals, longer duration WBVE protocols may be planned, and a prolonged intervention might help amend muscle and bone loss in this diseased population. Caution should be taken when determining overweight or obesity in inflammatory rheumatic diseases and lupus individuals with chronic GC using only BMI since it was demonstrated that there was a discrepancy between BMI, BF% and FMI [33; 36]. These characteristics may misestimate morbidity in this population. [PERSON] 2019 [15] pointed out that despite the cardiovascular and psychosocial benefits conferred by physical activity, SLE individuals do not exercise adequately in general. Figure 5: sEMG analysis of muscles gastrocnemius medialis, vastus lateralis and tibialis anterioris. SLE OPIA—SLE individuals with OPIA, SLE—individuals without OP or OPIA, CG—non-lupus individuals. GM—gastrocnemius medialis, VL—Vastus lateralis, TA—tibialis anterioris. Statistical test: ANOVA. *_p_\(<\)0.05. (**a**): % increase in EMGrms of GM, (**b**): % increase in EMGrms of VL, (**c**): % increase in EMGrms of TA. In the current study, considering the characteristics of the biological responses of the WBVE [17; 18; 19; 20], this modality of exercise might be of benefit in the management of SLE individuals. Lupus individuals had acute increases in activation of VL, GM and TA during WBVE measured by sEMG. In respect of the hypotheses, all three groups demonstrated similar increased activation of VL in the lowest frequency implemented in this investigation, 30 Hz; GM demonstrated the best activation in 30 Hz, especially for controls. To our knowledge, this is the first study that evaluated WBVE effects on lupus individuals. The importance of studying different categories of PE relies on the fact that recommendations of exercises to amend decreased mobility and bone loss should be tailored to each group of diseases' needs and peculiarities [31]; SLE patients cannot be sun exposed and may have movement impairments secondary to arthritis, circulatory and neurologic sequelae [35]. Although there are several effective medications that are utilized to treat GIOP [10; 37; 38], these agents have no effect on other key fracture risk factors, such as muscle weakness, diminished functionality and altered body composition. The interaction of mechanical vibration with the structures of the body would induce the process of muscle activation and bone formation [39]. Most studies on WBVE for OP treatment were performed with post-menopause, elderly, institutionalized patients [40; 41; 42] and several of the obtained outcomes demonstrated an increase in BMD, better functionality and enhanced muscle strength and power [43; 44; 45; 46]. A recent systematic review on children with Duchenne muscular dystrophy with chronic GC use demonstrated improvements in bone mass only with WBVE and risedronate, a commonly used drug for the treatment of OP [47]. As muscle stimulation and bone remodeling are directly related, it is plausible to evaluate two groups of the same disease that differ on bone mass. The occurrence of osteoporosis could affect muscle functioning so that mechanical vibration would not demonstrate the same effects. A single different parameter on intervention might show this distinction, especially frequency, which has the most impact on apeak results [48]. The mechanisms by which the mechanical vibrations act on muscle would be associated to the stretch reflex [49]. Increases on sEMGrms for lower limb muscles of older populations when compared to young individuals were prominent [50; 51]. The authors relate the lower strength of old adults to the higher activation while standing on the functioning VP, as an attempt of adaptation, which may further improve stability and muscle power [26]. Although chronic GC use is associated with muscle deterioration [52], the individuals of the current investigation did not demonstrate differences in lean mass composition, even the SLE OPIA group having bone waste.