## 4 Discussion
[23] assessed the effect of sinusoidal vibrations on urinary incontinence and also noted symptom relief in patients with incontinence. [PERSON] et al. analyzed the effect of SR-WBV vibrations of different durations (continuous, 60 s, and intermittent, 15 s) on the pelvic floor muscles. When there were no statistically significant differences found, continuous vibrations were recommended (60 s), which is consistent with the methodology used in this study [24]. There are no studies available about the effect of SR-WBV on mood or mental state. In the present study, 51% of all women who completed the training cycle declared an improvement in their mental state and 72% in their general well-being. Most likely, this is due to a general improvement in health and reduction in pre-existing symptoms. An improvement in health and life quality will improve mood and general well-being. After SR-WBV training, only two patients reported mental state deterioration. In one patient, it was most likely related to the death of the patient's brother and not to the therapy, while, in the other person, it was associated with the therapy because, at the end of the procedure, knee pain appeared. Most respondents declared an improvement in health problems. Eighty-four percent of women with lower limb pain declared improvement, and only about 3% (N = 1) reported deterioration. As for back pain, an improvement was noticed in about 50% of women and, in the case of shoulder and hand pain, in about 31% of women experiencing such symptoms. [PERSON] et al. [25; 26] also investigated the effect of SR-WBV on muscle pain. Participants of the study reported slight improvements immediately after the first stochastic resonance training session, which gradually progressed with further trainings. The most frequently reported positive effects after SR-WBV were skin firming and cellulite reduction (11%) and improvement in sleep quality and in falling asleep (7%). In the present study, a greater improvement in physical fitness and urinary incontinence symptoms was found in the group of women using the O program compared to those enrolled in the D program. These differences may be attributed to two reasons: (1) The highest vibration level (9 vibration series) on the D program was used, which, together with the breaks, lasted 16 min. However, on the O program, 11 vibration series were used, which, together with breaks, lasted 22 min. Although in the O program, due to the type of noise and amplitude, vibrations are less noticeable, the increased number of series seems to be important in the effectiveness of the training. (2) The fact that the qualification for training on each particular program was not randomized may also have played a role in the higher effectiveness of the O program. Women with worse overall health and pain symptoms were referred to the O program. These women were more likely to be susceptible to vibration than those with a lack of or little health problems in their medical history, who were primarily referred to the D program. If used improperly, SR-WBV training can cause negative effects. In the available literature, it is not easy to find information about the adverse effects of SR-WBV. In 2007, [PERSON] et al. [27] described an acute renal colic episode after a single WBV cycle in a patient with asymptomatic kidney stones. [PERSON] et al. [28] excluded five out of ninety-four people who had developed knee pain. However, side effects described in the literature refer to studies using sinusoidal vibrations. Due to the variable vibration characteristic and the type of \"noise\" applied in SR-WBV training, lower frequency and lower amplitude vibrations may be used, compared to the typical WBV training where sinusoidal vibrations are applied. In this study, during SR-WBV training, vibration frequencies ranged from 2 to 8 Hz, and those trained at medium- or low-level frequencies did not exceed 6 Hz. For comparison, in the WBV training with sinusoidal vibrations in the studies of [PERSON] et al.