Myofascial force transmission: muscle relative position and length determine agonist and synergist muscle force
Myofascial force transmission: muscle relative position and length determine agonist and synergist muscle force
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DOI：
10.1152/japplphysiol.00173.2002
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发表时间：
2003-03-01
影响因子：
3.3
通讯作者：
Baan, GC
中科院分区：
文献类型：
--
作者：
Huijing, PA;Baan, GC
研究了大鼠指长伸肌（EDL）近端和远端相等的延长。胫骨前肌、拇长伸肌和EDL肌活动最大。这些肌肉腹部周围的结缔组织完好无损。近端EDL力与远端力不同，表明肌筋膜力传递到肌腱以外的结构。远端延长后施加的EDL远端力比近端延长后施加的EDL远端力高（比例约为118%）。对于近端力，发生了相反的情况（比例接近157%）。在延长端施加的被动EDL力是在未延长端施加的力的7-10倍。当长度保持不变时，增效肌（胫前肌+拇长伸肌：活动肌力差接近-10%）在远端EDL延长时力显著降低，而在近端EDL延长时则没有。我们得出的结论是，由于肌筋膜力传递对腹部肌肉部分施加的额外负荷，施加在肌肉延长端肌腱上的力更高。这是由延长肌肉的大部分相对于邻近肌肉和隔室结缔组织的相对位置的变化所介导的。因此，肌肉的相对位置是肌肉力的主要共同决定因素，其腹部的连通性接近于体内条件。
Equal proximal and distal lengthening of rat extensor digitorum longus (EDL) were studied. Tibialis anterior, extensor hallucis longus, and EDL were active maximally. The connective tissues around these muscle bellies were left intact. Proximal EDL forces differed from distal forces, indicating myofascial force transmission to structures other than the tendons. Higher EDL distal force was exerted (ratio approximate to118%) after distal than after equal proximal lengthening. For proximal force, the reverse occurred (ratio approximate to157%). Passive EDL force exerted at the lengthened end was 7-10 times the force exerted at the nonlengthened end. While kept at constant length, synergists (tibialis anterior + extensor hallucis longus: active muscle force difference approximate to -10%) significantly decreased in force by distal EDL lengthening, but not by proximal EDL lengthening. We conclude that force exerted at the tendon at the lengthened end of a muscle is higher because of the extra load imposed by myofascial force transmission on parts of the muscle belly. This is mediated by changes of the relative position of most parts of the lengthened muscle with respect to neighboring muscles and to compartment connective tissues. As a consequence, muscle relative position is a major codeterminant of muscle force for muscle with connectivity of its belly close to in vivo conditions.