Tottori Nobuaki, Suga Tadashi, Miyake Yuto, Tsuchikane Ryo, Otsuka Mitsuo, Nagano Akinori, Fujita Satoshi, Isaka Tadao
1 Ritsumeikan University.
Pediatr Exerc Sci. 2018 Feb 1;30(1):115-123. doi: 10.1123/pes.2016-0226. Epub 2017 Oct 20.
We attempted to determine the relationships between the cross-sectional area (CSA) of the trunk and lower limb muscles and sprint performance in male preadolescent sprinters.
Fifteen sprint-trained preadolescent boys (age 11.6 ± 0.4 y) participated in this study. The CSAs of the participants' trunk and lower limb muscles were measured using magnetic resonance imaging, and these muscles were normalized with free-fat mass. To assess participants' sprint performance, sprint time and variables during the 50-m sprint test were measured. The sprint variables were expressed as their indices by normalizing with body height.
The relative CSAs of psoas major, adductors, and quadriceps femoris were significantly correlated with sprint time (r = -.802, -.643, and -.639). Moreover, the relative CSAs of these muscles were significantly correlated with indices of sprint velocity (r = .694, .612, and .630) and step frequency (r = .687, .740, and .590) but not with that of step length.
These findings suggest that greater hip flexor and knee extensor muscularity in male preadolescent sprinters may help achieve superior sprint performance by potentially enhancing their moments, which may be induced by increased step frequency rather than step length during sprinting.
我们试图确定男性青春期前短跑运动员躯干和下肢肌肉的横截面积（CSA）与短跑成绩之间的关系。
15名经过短跑训练的青春期前男孩（年龄11.6±0.4岁）参与了本研究。使用磁共振成像测量参与者躯干和下肢肌肉的CSA，并将这些肌肉与去脂体重进行标准化。为了评估参与者的短跑成绩，测量了50米短跑测试中的短跑时间和变量。通过与身高进行标准化，将短跑变量表示为它们的指数。
腰大肌、内收肌和股四头肌的相对CSA与短跑时间显著相关（r = -0.802、-0.643和-0.639）。此外，这些肌肉的相对CSA与短跑速度指数（r = 0.694、0.612和0.630）和步频（r = 0.687、0.740和0.590）显著相关，但与步长指数无关。
这些发现表明，男性青春期前短跑运动员更强的髋部屈肌和膝部伸肌力量可能通过潜在地增强其力矩来帮助实现卓越的短跑成绩，这可能是由短跑过程中步频增加而非步长增加所导致的。
