摘要
研究的主要目的是探索能够测定肌纤维组成的无损指标。首先让受试者做两次最大用力等长伸膝,较大的作为最大等长收缩力量(MVC)。测定出腿围(C)和相对肌力(MVC/C)等指标。在维持70%MVC 等长收缩至疲劳过程中,记录股外肌表面肌电图(EMG)信号和积分肌电图(IEMG)信号。受试者股外肌的肌纤维组成用活检测定法测定。实验结果表明,在维持70%MVC 等长收缩至疲劳过程中,肌电图功率谱平均功率频率(MPF)逐渐下降,IEMG 逐渐上升,股外肌FT%与MPF 的降低和IEMG 的上升之间存在线性相关。
The purpose of the study was to determine the non-invasive indexes of the composition ofmuscle fiber.The subjects performed two maximal isometric knee extension,with the larger value recordedas MVC.Muscle circumference(C),relative muscle force(RMVC=MVC/C)and some other indexeswere measured.The surface electromyogram(EMG)and integrated EMG(IEMG)during fatiguingisometrie contraction at 70% MVC were recorded.Biopsy samples were obtained to measure the composi-tion of vastus lateral muscle fiber.The results showed a continuous decline in mean power frequency(MPP)and a continuous increase in IEMG.a linear relationship was found between the decline of MPPduring the sustained contraction and FT% and between the increase of IEMG and FT%.
关键词
肌纤维组成
肌电图
肌肉疲劳
muscle fiber composition
FT%
EMG
IEMG
MPF
isometric contraction
muscle fatigue
