Lovell R, Knox M, Weston M, Siegler J C, Brennan S, Marshall P W M
School of Science and Health, Western Sydney University, Penrith, NSW, Australia.
School of Social Sciences, Business & Law, Teesside University, Middlesbrough, UK.
Scand J Med Sci Sports. 2018 Feb;28(2):658-666. doi: 10.1111/sms.12925. Epub 2017 Jun 28.
We examined the effects of a 12-week program of Nordic hamstring exercises (NHE), administered before or after football training, upon eccentric hamstring strength, muscle activity, and architectural adaptations. Amateur soccer players were randomized into three groups. The control group (CON; n=11) undertook core stability exercises, whereas a periodized NHE program was delivered either before (NHE ; n=10) or after (NHE ; n=14) biweekly training sessions. Outcome measures included peak torque and concomitant normalized peak surface electromyography signals (sEMG) of the biceps femoris (BF) and medial hamstring (MH) muscles during knee flexor maximal eccentric contractions, performed at 30°·s . Ultrasonography was used to determine BF muscle thickness, muscle fiber pennation angle, and fascicle length. Performing the NHE derived likely moderate peak torque increases in both NHE (+11.9%; 90% confidence interval: 3.6%-20.9%) and NHE (+11.6%; 2.6%-21.5%) vs CON. Maximum sEMG increases were moderately greater in the BF of both NHE training groups vs CON. There were likely moderate increases in BF muscle thickness (+0.17 cm; 0.05-0.29 cm) and likely small pennation angle increases (+1.03°; -0.08° to 2.14°) in NHE vs CON and NHE . BF fascicle length increases were likely greater in NHE (+1.58 cm; 0.48-2.68 cm; small effect) vs CON and NHE . A 12-week eccentric hamstring strengthening program increased strength and sEMG to a similar magnitude irrespective of its scheduling relative to the football training session. However, architectural adaptations to support the strength gains differed according to the timing of the injury prevention program.
我们研究了在足球训练之前或之后进行的为期12周的北欧腘绳肌练习（NHE）计划对腘绳肌离心力量、肌肉活动和结构适应性的影响。将业余足球运动员随机分为三组。对照组（CON；n = 11）进行核心稳定性练习，而在每两周一次的训练课程之前（NHE；n = 10）或之后（NHE；n = 14）进行一个阶段性的NHE计划。结果指标包括在以30°·s进行的膝关节屈肌最大离心收缩过程中，股二头肌（BF）和腘绳肌内侧（MH）的峰值扭矩以及相应的标准化峰值表面肌电图信号（sEMG）。使用超声检查来确定BF肌肉厚度、肌纤维羽状角和肌束长度。与CON组相比，进行NHE训练的NHE组（增加11.9%；90%置信区间：3.6% - 20.9%）和NHE组（增加11.6%；2.6% - 21.5%）可能使峰值扭矩有适度增加。两个NHE训练组的BF肌肉最大sEMG增加幅度均适度大于CON组。与CON组和NHE组相比，NHE组的BF肌肉厚度可能有适度增加（+0.17 cm；0.05 - 0.29 cm），羽状角可能有小幅增加（+1.03°； - 0.08°至2.14°）。与CON组和NHE组相比，NHE组的BF肌束长度增加可能更大（+1.58 cm；0.48 - 2.68 cm；小效应）。无论相对于足球训练课程的安排如何，为期12周的离心腘绳肌强化计划都能使力量和sEMG增加到相似程度。然而，根据预防损伤计划的时间安排，支持力量增加的结构适应性有所不同。
