## 4 Discussion
After classifying the players in relation to the optimal value of age (13.5 years or older), it was found that the HPG-LBK players had higher values in the evaluated variables such as age, body mass, body height, body mass index, leg length, soccer background, HE ROM, KF ROM, HE MIS and KF MIS. On the other hand, no differences in soccer background were found depending on the cut-off value of age (13.5 years or older), but a significant trend is observed in minutes played weekly in competition (average difference 13 min). Soccer players at a higher performance level generally have higher values for kinanthropometric variables such as body mass, body height, lower limb length and body mass index than players at a lower performance level [3; 39; 40]. Players with delayed biological maturation in any age group are likely to have lower ball-kicking performance due to disadvantages in body mass, body height and muscle mass [35]. The differences in biological maturation in the form of growth spurts and changes in body composition, as well as the changing dimensions of the soccer field, have a greater impact on the physical, technical and tactical performance of pre-pubertal adolescent players than on pubertal or post-pubertal players [3; 35]. As far as the authors are aware, previous studies have shown no relationship or association between the variables (body mass, body height and body mass index) and kicking performance (maximum horizontal distance). Players of older age and greater body height, body weight, leg mass and relative lean mass kick the ball with greater speed and accuracy using both limbs, the dominant and non-dominant sides [3; 5; 41; 42]. Taller soccer players perform better in technical actions that require speed and strength due to the mechanical advantage of longer limbs [35; 43]. However, no differences were found in aerobic endurance and soccer-specific skills such as short passing, kicking accuracy or ball control [43]. [PERSON] et al. found that body mass correlates with kicking speed and the 30 m sprint. Body height correlated with vertical jump height, 10 m and 30 m sprint, distance in the Yo-Yo Intermittent Running Test and running time in a maximal oxygen consumption test [44]. In other sports, a larger body size (arm or forearm length) is associated with faster ball speed in handball players [45; 46] and a faster ball strike in tennis [47]. Our results support these findings in relation to the maximum horizontal distance of the ball after kick in players with greater height or lower limb length, resulting in a higher kick performance in soccer (HPG-LBK). Based on these findings, youth soccer coordinators and coaches should consider the variation in kinanthropometric variables within age groups or competition categories when planning sports, especially in young players between 12 and 20 years of age, in order to achieve higher athletic performance with lower risk of injury [5]. In contrast, after biological development, no correlation was found between body weight and height and kicking performance, especially kicking speed, in older players, such as college [48] and Senior soccer players [49]. The results show higher ROM-HE and ROM-KF in those players achieving LBK (\(\geq\)30 m). These results are consistent with previous research assessing HF-KE ROM [50; 51; 52]. Correlations were found between hip-extension ROM and some of the kicking variables, such as HE ROM and KF ROM, during kicking in 60 men aged between 18 and 33 years [50]. [PERSON] et al. [51] showed that 43 young male soccer players (aged 14-18 years) with good hamstring flexibility (HF-KE ROM) performed better in tests of acceleration and sprinting (5 m, 10 m and 20 m), countermovement jump, Balsom agility and kicking speed in relation to ball speed than players with lower hamstring flexibility [51]. [PERSON] et al. concluded that HF-KE ROM may be a crucial factor in skill performance, as shown by the deficits in kicking in soccer players with shortened hamstrings compared to athletes with stretched hamstrings [52].