e Lima Kelly M M, Carneiro Simone P, Alves Daniel de S, Peixinho Carolina C, de Oliveira Liliam F
*Biomedical Engineering Program, COPPE/Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; and †School of Physical Education and Sports, Department of Biosciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
Clin J Sport Med. 2015 Jan;25(1):55-60. doi: 10.1097/JSM.0000000000000069.
To evaluate the chronic effects of a static stretching program on the muscle architecture of biceps femoris (BF) and vastus lateralis (VL) muscles in ultrasound (US) images.
Randomized controlled longitudinal trial.
Biomechanics Laboratory of Physical Education School of the Army, Rio de Janeiro, Brazil.
The study included 24 healthy and physically active male volunteers (19.05 ± 1.40 years, 1.73 ± 0.07 m, and 73.15 ± 8.33 kg), randomly allocated to 1 of 2 groups: stretching group (SG, n = 12) and control group (n = 12).
The SG was submitted to 3 sets of 30 seconds of static stretching 3 times a week during 8 weeks.
Ultrasound equipment (7.5 MHz) was used for the evaluation of BF and VL muscle architecture variables (pennation angle, fiber length, muscle thickness, and fascicle displacement) before and after training. Knee range of motion (ROM) and isometric flexion and extension torque (TQ) were also measured.
There were no significant changes in muscle architecture, TQ, and maximum knee flexion angle (P > 0.05). However, maximum knee extension angle (MEA) increased significantly in the SG (pretraining: 159.37 ± 7.27 degrees and posttraining: 168.9 ± 3.7 degrees; P < 0.05).
Volume or intensity (or both) of the stretching protocol was insufficient to cause structural changes in the VL and BF muscles. The increase in MEA could not be explained by muscle architecture changes.
To describe changes in the VL and BF muscle tendon unit using US after a long-term stretching program to identify which structures are responsible for ROM increase.
评估静态拉伸计划对超声（US）图像中股二头肌（BF）和股外侧肌（VL）肌肉结构的慢性影响。
随机对照纵向试验。
巴西里约热内卢陆军体育学院生物力学实验室。
该研究纳入了24名健康且有体育活动习惯的男性志愿者（19.05±1.40岁，身高1.73±0.07米，体重73.15±8.33千克），随机分为两组：拉伸组（SG，n = 12）和对照组（n = 12）。
拉伸组在8周内每周进行3次，每次3组，每组30秒的静态拉伸。
训练前后使用超声设备（7.5兆赫）评估BF和VL肌肉结构变量（羽状角、纤维长度、肌肉厚度和肌束位移）。还测量了膝关节活动范围（ROM）以及等长屈伸扭矩（TQ）。
肌肉结构、TQ和最大膝关节屈曲角度无显著变化（P>0.05）。然而，拉伸组的最大膝关节伸展角度（MEA）显著增加（训练前：159.37±7.27度，训练后：168.9±3.7度；P<0.05）。
拉伸方案的量或强度（或两者）不足以引起VL和BF肌肉的结构变化。MEA的增加无法用肌肉结构变化来解释。
描述长期拉伸计划后使用超声观察到的VL和BF肌肉肌腱单位的变化，以确定哪些结构导致了ROM的增加。
