## 4 Results and Discussion
### WBVE and Mental Conditions  
It is pointed out that the COVID-19 infection can, directly or indirectly, influence the central nervous system, potentially causing neurological diseases. In consequence, chronic COVID-19-related disease processes have the potential to cause serious and undesirable mental illnesses, including depression, anxiety, and sleep disorders [88]. Moreover, it has been reported that patients with COVID-19 experienced high levels of anxiety, depression, and stress, and the result of a randomized trial highlights the effectiveness of cognitive behavioral therapy (CBT) in improving the psychological health among patients with COVID-19 [89]. WBV exercise seems to improve parameters related to the cognition. [PERSON] et al., 2015 [90]; [PERSON] et al., 2014 [91]; and [PERSON] et al., 2014 [92] investigated the effects of whole-body vibration exercise on neurocognition in healthy subjects, [PERSON] et al., 2018 [93] in mild or moderate dementia and [PERSON] & [PERSON], 2018 [56] in women with senile dementia, [PERSON] et al., 2014 [94; 95] study in attention-deficit/hyperactivity disorder (ADHD) individuals and [PERSON] et al., 2020 [54] in women with lumbar hyper-lordosis. These authors performed their experiments using different mechanisms (vibration vertical and alternating vibration) and different models of the vibrating platform. The time of exposure to vibration varied from 30 s to 2 min and the frequency used from 30 Hz and 2 to 5 mm in amplitude. In relation to the total sample, it was composed of individuals of both sexes and different conditions, and the protocol of vibration variety the acute to accumulative effects. [PERSON] et al., 2015 [90], studied a protocol of WBV exercise in 4 different days, with 3-14 days between test sessions, where the subjects completed five sets of 2-min repetitions of static squats in each exercise session. It was concluded that a single bout of static squats with of knee flexion while undergoing WBV exercise at 30 Hz with 4 mm of vertical displacement does not cause a significant decrease in neurocognition, does not affect visual or verbal memory, reaction time or impulse control measured using ImPACT, but motor processing and speed can be increased after VV. It is likely that the head accelerations resulting from this protocol are insufficient to cause acute injury. [PERSON] et al., 2014 [91] investigated the effects of 12 sessions, with each session (passive WBV or control) lasted two minutes, and a rest period of three minutes while sitting on the WBV chair (without vibration). It was showed that two minutes passive WBV has positive acute effects on attention and inhibition in young adults, notwithstanding their high cognitive functioning which could have hampered improvement. [PERSON] et al., 2018 [93] concluded that the WBV training is feasible and safe to use with people with mild or moderate dementia. However, it did not lead to further improvement in physical function and quality of life than the usual activity program provided at the daycare centers, in a protocol performed 9 weeks (18 sessions), 2 days per week. [PERSON] & [PERSON], 2018 [81], pointed out that the WBV can be used in the improvement of the quality of life of subjects with senile dementia showing enhancement in EEG activation and cognitive function through the responses of the neuromuscular system. The improvement would be obtained by stimulating of muscle spindles and sensory organs through the mechanical vibration without additional burden of physical activity. The protocol was performed with WBV exercise during five times a week for eight weeks, whole body stretching was done mildly, as warm-up and warm-down exercise. [PERSON] et al., 2014 [92], reported that 3-min of WBV presented reduction on inhibition in healthy children. The experiment itself consisted of six trials. Each trial started with a three-minute period which was either (A) a period of WBV (vibration condition), or (B) a resting period of no vibration (non-vibration condition).