## 4 Discussion
In this situation, the nerve fibers in the skin are stimulated more and then the phenomenon of increased current flow through the skin appears, i.e., the dose of electricity is higher in the skin. It should be noted that even within the skin located under the electrode, the electric current density is unevenly distributed due to uneven skin resistance [25; 30; 31]. This is probably why, in our study, it was shown that women with a higher body fat percentage had a lower current perception threshold. Similar results were obtained by [PERSON] et al. [31], who studied 30 obese women and compared them with their non-obese peers. They found that obese individuals had lower excitability. According to [PERSON] et al. [8], the mechanism described above results in a lowered perception threshold in people with a higher body fat percentage compared to people with a low body fat percentage, and this does not hinder the flow of electricity deep into the body. Therefore, a source of the variability in the perception threshold observed between individuals may be the variability in body fat percentage. It is well known that women have a higher percentage of body fat than men, and studies have shown that the perception threshold in women is lower than in men, which may mean that the reportedsensations are related to an individual's body fat percentage [8]. In other studies using TENS stimulation [26; 31; 32], in which factors that could affect changes in the perception threshold were studied, a relationship was demonstrated between the subcutaneous fat mass and sensation, suggesting that one of the factors influencing sex differences in the perception of electric current is the skin fold thickness. The perception of the current is also influenced by the thickness of the skin itself, as it affects the distance between the source of the stimulus and the nerve endings in the skin [8]. Generally speaking, the greater the distance between the current source and the activated nerve endings, the greater the loss of free flow of an electric charge and the greater the impedance. Hence, a higher average is needed to activate the receptor or afferent nerve fibers, resulting in a higher perception threshold. Some authors [26; 31; 32] have also suggested that the number of epidermal nerve fibers and the intra-epidermal nerve fiber density may affect individual sensitivity to electrical stimulation, as well as the differences between the sexes in the perception of stimuli. Changes in the density of the nerve endings located under the electrodes may be the source of variability in the perception threshold; however, in this research, it seems that errors related to this factor were avoided, because all of the subjects had the tests performed on the same area of the forearm. During the test, the electrodes were placed on the interior surface of the forearm. The consistent and precisely defined position of the electrodes also minimized errors that may have resulted from the different perceptions of electrical stimuli in different parts of the human body, entirely due to the differences in skin thickness and innervation density in a given area of the body. In this study, taller women had higher current perception threshold values compared to shorter women. This result can probably be explained by the longer axons found in the bodies of taller women, and the possible lower density of receptors in the skin of taller people, as has been found with thermoreceptors and which may also apply to other skin sensory receptors [32]. In another study [33], in which the authors studied the relationship between finger and toe vibrotactile thresholds and age and height, it was stated that the length of the peripheral nerve axons may be a predictor of changes in vibration sensitivity, i.e., the taller the examined person, the longer the axons and the lower the sensitivity to external stimuli. The authors [30], however, only showed differences in the perception of stimuli in subjects' lower limbs, but no differences were found in the upper limbs.