School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taiwan, ROC.
Scand J Med Sci Sports. 2010 Feb;20(1):e80-6. doi: 10.1111/j.1600-0838.2009.00908.x.
This study measured the potentiation effects of plyometric training [normalized electromyography (EMG) in triceps surae, stiffness and elastic energy utilization of the Achilles tendon] and investigated the correlations between these effects and performances [voluntary electromechanical delay (EMD) and jump height]. Twenty-one subjects were randomly assigned either to the control group (10 subjects: age 22.3+/-1.6 years) or to a training group (11 subjects: age 22.1+/-1.6 years) that performed 8 weeks of plyometric training.
As compared with the performances before training, normalized EMG in the soleus were significantly (P<or=0.001) increased after 4 and 8 weeks of training. Tendon stiffness, elastic energy storage, release and jump height determined after training were significantly increased (P<0.05), with a concomitantly reduced voluntary EMD (P=0.01). These variables also showed significant differences vs the control group (all P<0.05). The other variables remained unchanged. Correlations were observed between tendon stiffness and either voluntary EMD (r=-0. 77, P=0.014) or jump height (r=0.54, P=0.031).
Plyometric training specifically potentiated the normalized EMG, tendon stiffness and elastic energy utilization in the myotendinous complex of the triceps surae. Although these changes are possibly essential determinants, only increases of tendon stiffness were observed to correlate with performance improvements.
本研究测量了增强式训练（比目鱼肌标准化肌电图、跟腱的硬度和弹性能量利用）的增效作用，并探讨了这些作用与表现（主动电机械延迟（EMD）和跳跃高度）之间的相关性。21 名受试者被随机分配到对照组（10 名受试者：年龄 22.3±1.6 岁）或训练组（11 名受试者：年龄 22.1±1.6 岁），进行 8 周的增强式训练。
与训练前的表现相比，训练 4 周和 8 周后比目鱼肌的标准化肌电图显著增加（P≤0.001）。训练后测定的跟腱硬度、弹性储能、释放和跳跃高度显著增加（P<0.05），同时主动 EMD 降低（P=0.01）。与对照组相比，这些变量也显示出显著差异（均 P<0.05）。其他变量保持不变。跟腱硬度与主动 EMD（r=-0.77，P=0.014）或跳跃高度（r=0.54，P=0.031）之间存在相关性。
增强式训练特别增强了比目鱼肌复合体的标准化肌电图、跟腱硬度和弹性能量利用。尽管这些变化可能是重要的决定因素，但只有跟腱硬度的增加与表现的提高相关。
