Alonso-Fernandez Diego, Fernandez-Rodriguez Rosana, Abalo-Núñez Rocío
Department of Special Didactics, Faculty of Science Education and Sport, University of Vigo, Vigo, Spain.
Galicia Sur Health Research Institute (IIS Galicia Sur), Vigo, Spain.
J Sports Med Phys Fitness. 2019 Apr;59(4):640-647. doi: 10.23736/S0022-4707.18.08873-4. Epub 2018 Oct 1.
Injuries and mechanical stimuli alter the muscle architecture and, therefore, its function. The changes in the architecture of the rectus femoris (RF) induced by an eccentric training protocol with reverse nordic hamstring exercises (RNHE) have never been studied. Therefore, the aim of the present study was to determine the architectural adaptations of the RF after an eccentric training with RNHE, followed by a subsequent detraining period.
Twenty-six subjects performed a first week of control, 8 weeks of eccentric training, concluding with a 4-week period of detraining. The architectural characteristics of the RF were evaluated using 2D ultrasound at rest (pretest: week 1), after the training (post-test: week 9), and at the end of the detraining period (retest: week 13).
At the end of the training period, a significant increase in the muscle fascicle length (FL) (t=-8.96, d=2.22, P<0.001), muscle thickness (MT) (t=-8.76, d=2.219, P<0.001), pennation angle (PA) (t=-9.83, d=2.49, P<0.05) and cross-sectional area (CSA) (t=-13.06, d=3.06, P<0.001) was observed. After the detraining period FL, MT, PA and CSA showed a significant decrease.
The eccentric training with RNHE may cause changes in the architectural conditions of RF, which, in addition, are also reversible after a 4-week detraining period. The adaptations produced by RNHE may have practical implications for injury prevention and rehabilitation programs, which include the changes in muscle architecture variables.
损伤和机械刺激会改变肌肉结构，进而影响其功能。从未有研究探讨过采用反向北欧绳肌练习（RNHE）的离心训练方案对股直肌（RF）结构的影响。因此，本研究旨在确定采用RNHE进行离心训练后以及随后的停训期后RF的结构适应性变化。
26名受试者先进行为期1周的对照期，然后进行8周的离心训练，最后是4周的停训期。在静息状态（预测试：第1周）、训练后（后测试：第9周）和停训期结束时（重新测试：第13周），使用二维超声评估RF的结构特征。
在训练期结束时，观察到肌肉束长度（FL）（t=-8.96，d=2.22，P<0.001）、肌肉厚度（MT）（t=-8.76，d=2.219，P<0.001）、羽状角（PA）（t=-9.83，d=2.49，P<0.05）和横截面积（CSA）（t=-13.06，d=3.06，P<挑战0.001）显著增加。停训期后，FL、MT、PA和CSA显著下降。
采用RNHE的离心训练可能会导致RF结构状况发生变化，此外，在4周的停训期后这些变化也是可逆的。RNHE产生的适应性变化可能对包括肌肉结构变量变化在内的损伤预防和康复计划具有实际意义。
