## 4 Discussion  
In the present study, we documented a sex-related effect in absolute cervical strength values, with males presenting greater values (20-38%, depending on the movement direction) than females in all the tested movement directions. The results of this study are in line with previous investigations in the scientific literature in which males have greater absolute cervical strength values in comparison with females [32; 33; 34; 37; 43]. The sex-related differences in cervical strength values may be attributed to different factors, such as the head and neck anthropometric parameters and geometry/morphology (i.e., females have smaller external neck and vertebral dimensions, as well as more slender necks and less neck cross-sectional area) [37], the basic anthropometric characteristics (body mass and/or body height) [34], the higher concentrations of anabolic hormones observed in male individuals, and probably the higher voluntary neural activity of the muscle actions [58; 59], as well as the different lifestyle behaviors (i.e., higher levels of physical activity observed in males compared to females). As mentioned earlier, the basic anthropometric characteristics (body mass and body height) could affect absolute cervical strength values. This notion has been strengthened by the results of this and previous studies which reported a significant relationship between body mass, body height, or body mass index with cervical strength measurements [32; 41], although there are studies that did not find a significant relationship between basic anthropometric characteristics and cervical strength values [33]. It seems that the correlation of basic anthropometric characteristics (especially of body mass) with cervical strength is higher in physically active and trained individuals, whereas this correlation in a normal population is much lower [34; 35]. Furthermore, some researchers found sex-related differences in the correlation of basic anthropometric characteristics with cervical strength [34; 38]. It should also be mentioned that in the present study, when the absolute cervical strength values were adjusted to body height, significant sex-related differences (males reported greater values than females) remained after height adjustment; however, the differences between males and females were significantly lower (forward flexion: 30%, extension: 9%, lateral flexion: 12.4-12.5%) compared to those observed in absolute values (forward flexion:37.7%, extension: 20.4%, lateral flexion: 23.3-23.7%). On the other hand, when the absolute values were adjusted to body weight, the only sex-related difference between males and females was observed in forward flexion (21.7%), while in the other movement directions, no significant sex-related differences were observed. The results of this study are in line with those of [PERSON] et al. [40], who reported greater sex-related differences in absolute cervical strength values (mean difference 55%) compared to relative values per body mass (mean difference 30%) or body mass index (mean difference 41%). In the present study, we also found no significant difference in lateral flexion cervical strength between the right and left side (mean % difference: 1.3-1.8) in both males and females. The results of the present study are in agreement with previous studies that also reported no significant differences between right and left lateral flexion in adults and adolescents [21; 32; 60], due to the bilateral arrangement of the involved musculature in different activities of daily life, as well as in different sport activities. On the other hand, [PERSON] et al. [26] and [PERSON] et al. [33] demonstrated significant difference (6-11%) in cervical lateral flexion strength between the right and left sides in males, but no difference was found in women [33]. [PERSON] et al.