Department of Sport Sciences, Nutrition and Health, Faculty of Exercise Science, University of Milan, Italy.
J Strength Cond Res. 2010 Mar;24(3):687-94. doi: 10.1519/JSC.0b013e3181c7b443.
The purpose of this study was to examine the effects of static stretching on leg extensor muscles during squat jump (SJ) at different knee starting angles. Seventeen male subjects (23 +/- 3 years, 179 +/- 5 cm, and 74 +/- 6 kg) performed on a force platform 2 series (preceded or not [control condition] by 10-minute static stretching of quadriceps and triceps surae muscles) of SJs at different knee starting angles: 50 degrees, 70 degrees, 90 degrees, and 110 degrees. Squat jump height, peak force, maximal acceleration, velocity, and power were calculated for each jump. The angle that maximized power development was obtained from the power-angle relationship. The SJ height, peak force, and maximal velocity increased according to angle amplitude in both control and stretching conditions (p < 0.01), performance being significantly lower in the stretching condition (p < 0.01). Peak power was obtained at 90 degrees in both control and stretching conditions, but was significantly lower (p < 0.01) after stretching. These results suggest that an acute bout of static stretching reduces power and force development during SJ, decrements being significantly higher at lower knee starting angles. Therefore, the use of static stretching may be questionable in those power activities requiring maximal power output at knee angles near full extension.
本研究旨在探讨在不同膝关节起始角度下，静态伸展对深蹲跳（SJ）时伸肌的影响。17 名男性受试者（23 ± 3 岁，179 ± 5cm，74 ± 6kg）在力量平台上进行了 2 组 SJ 测试（一组在进行 10 分钟股四头肌和比目鱼肌的静态伸展之前[对照条件]，另一组不进行），膝关节起始角度分别为 50°、70°、90°和 110°。计算了每次跳跃的深蹲跳高度、峰值力、最大加速度、速度和功率。根据功率-角度关系得出了最大化功率发展的角度。在对照和伸展条件下，SJ 高度、峰值力和最大速度均随角度幅度的增加而增加（p<0.01），伸展条件下的表现明显较低（p<0.01）。在对照和伸展条件下，峰值功率均在 90°时获得，但伸展后明显降低（p<0.01）。这些结果表明，急性的静态伸展会降低 SJ 时的功率和力量发展，在较低的膝关节起始角度下，降低幅度更大。因此，在需要在接近完全伸展的膝关节角度下输出最大功率的力量活动中，使用静态伸展可能值得怀疑。
