The effect of leg flexion angle on the mechanomyographic responses to isometric muscle actions
The effect of leg flexion angle on the mechanomyographic responses to isometric muscle actions
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DOI：
10.1007/s004210050418
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发表时间：
1998-08-01
期刊：
影响因子：
--
通讯作者：
Perry, SR
中科院分区：
文献类型：
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作者：
Ebersole, KT;Housh, TJ;Perry, SR
本研究的目的是探讨下肢屈曲角度对肌力图（MMG）振幅和等长扭矩产生之间关系的影响。成年男性（n = 9）在校准的CYBEX 6000测力计上，在低于完全伸展的25、50和75度下，在25%、50%、75%和100%最大自主收缩（%MVC）下进行腿部伸肌的等长肌肉动作。将压电MMG记录装置放置在股直肌的中部。下肢屈曲25 °时，MMG振幅增加至100%MVC。然而，在腿屈曲50和75 °时，MMG振幅增加到75%MVC，然后在75和100%MVC之间没有显著变化（P > 0.05）。这些发现表明MMG振幅-等距扭矩关系具有关节角度特异性，并且可能是腿部屈曲角度差异的结果：（1）肌肉僵硬，或（2）运动单元激活策略。
The purpose of this investigation was to examine the effect of leg flexion angle on the relationship between mechanomyographic (MMG) amplitude and isometric torque production. Adult males (n = 9) performed isometric muscle actions of the leg extensors at 25, 50, 75, and 100 percent maximal voluntary contraction (%MVC) on a calibrated CYBEX 6000 dynamometer at 25, 50, and 75 degrees below full extension. A piezoelectric MMG recording device was placed over the mid-portion of the rectus femoris. At 25 degrees of leg flexion, the MMG amplitude increased to 100%MVC. At 50 and 75 degrees of leg flexion, however, MMG amplitude increased to 75%MVC, and then did not change significantly (P > 0.05) between 75 and 100%MVC. These findings indicate that the MMG amplitude-isometric torque relationship is joint angle specific and may be the result of leg flexion angle differences in: (1) muscle stiffness, or (2) motor unit activation strategies.