MEDIAN FREQUENCY OF THE MYOELECTRIC SIGNAL - EFFECTS OF MUSCLE ISCHEMIA AND COOLING
MEDIAN FREQUENCY OF THE MYOELECTRIC SIGNAL - EFFECTS OF MUSCLE ISCHEMIA AND COOLING
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DOI：
10.1007/bf01015206
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发表时间：
1984-01-01
影响因子：
3
通讯作者：
DE LUCA, CJ
中科院分区：
文献类型：
--
作者：
MERLETTI, R;SABBAHI, MA;DE LUCA, CJ
研究了局部缺血或表面冷却引起肌内温度降低时肌电信号中位频率的变化。从涉及10名女性和16名男性受试者[人]的第一背侧骨间肌的实验中获得数据。这些受试者被要求进行等长恒定力外展收缩的食指在20%和80%的最大随意收缩水平。计算在收缩的前0.5s期间肌电信号的初始中值频率（IMF）。结果表明，在缺血条件下进行的收缩IMF的显着减少，释放后，IMF迅速恢复。在80%的最大自愿收缩水平下，记录到IMF的更大下降。在肌内温度降低过程中也证明了类似的结果，冷却后IMF逐渐恢复。这些结果表明，中值频率的肌电信号显示的行为类似于所报告的传导速度。这与肌肉组织中代谢副产物的积累导致肌纤维传导速度降低的观点一致。
The changes that occur in the median frequency of the myoelectric signal during local ischemia or reduction of intramuscular temperature produced by surface cooling was investigated. Data was obtained from experiments which involved the 1st dorsal interosseous muscle of 10 female and 16 male subjects [human]. These subjects were asked to perform isometric constant-force abduction contractions of the index finger at 20% and 80% of maximal voluntary contraction level. The initial median frequency (IMF) of the myoelectric signal during the first 0.5 s of contraction was calculated. Results showed a significant reduction of the IMF in contractions performed under ischemic conditions; upon release, the IMF recovered quickly. At 80% maximal voluntary level of contraction, a greater decrease of the IMF was recorded. Similar results were demonstrated during reduction of intramuscular temperature with gradual recovery of the IMF after cooling. These results demonstrate that the median frequency of the myoelectric signal displays behavior similar to that reported for conduction velocity. This is consistent with the notion that accumulation of metabolic byproducts in muscle tissue causes a decrease in the conduction velocity of the muscle fibers.