Approach run increases preactivation and eccentric phases muscle activity during drop jumps from different drop heights
Approach run increases preactivation and eccentric phases muscle activity during drop jumps from different drop heights
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DOI：
10.1016/j.jelekin.2009.08.007
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发表时间：
2010-10-01
影响因子：
2.5
通讯作者：
Li, Li
中科院分区：
文献类型：
--
作者：
Ruan, Mianfang;Li, Li
本研究的目的是探讨水平入路跑步和落点高度对落点跳跃过程中下肢肌肉激活的影响。10名参与者分别从15、30、45和60厘米的落差高度进行跳远，分别为0（站立）、1、2和3步。记录臀大肌（GM）、股直肌（RF）、股二头肌（BF）、股外侧肌（VL）、胫前肌（TA）、腓肠肌（GA）和比目鱼肌（SO）在激活前（着地前50 ms）、下行和推离阶段的肌电活动，并进行全波校正和平均（aEMG）。增加落差高度并没有提高除GA外其他肌肉的激活水平。在预激活阶段，除TA外所有肌肉的aEMG均随进路跑步数的增加而增加。下跑阶段，RF、BF、VL和SO的aEMG随跑步数的增加而增加，而推离阶段aEMG没有变化。这些结果表明，在跳高之前的水平跑是增加肌肉预激活水平的有效策略，这有助于在离心收缩阶段提高肌肉活动水平，并可能有助于在同心收缩阶段报告更高的功率输出。Elsevier Ltd.出版。
The purpose of this study was to investigate the effects of a horizontal approach run and drop height on the activation of lower extremity muscles during drop jumps. Ten participants performed drop jumps from drop heights of 15, 30, 45 and 60 cm with zero (standing), one, two, and three approach run steps. The EMG activities of the Gluteus Maximus (GM), Rectus Femoris (RF), Biceps Femoris (BF), Vastus Lateralis (VL), Tibialis Anterior (TA), Gastrocnemius (GA) and Soleus (SO) were recorded, full-wave rectified, and averaged (aEMG) during the preactivation (50 ms before touchdown), downward, and push-off phases. Increasing drop height did not enhance the muscle activation level of any examined muscles except GA. During the preactivation phase, the aEMG of all muscles except TA increased with the number of approach run steps. The aEMG of RF, BF, VL, and SO also increased with the number of approach run steps during the downward phase, while no aEMG changes were observed during the push-off phase. These results suggest that a horizontal approach run preceding the drop jump is an effective strategy for increasing the muscle preactivation level, which contributes to a higher level of muscle activity during the eccentric contraction phase and could potentially contribute to the reported higher power output during the concentric contraction phase. Published by Elsevier Ltd.