Rassier Dilson E, Herzog Walter
Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, AB, Canada.
J Electromyogr Kinesiol. 2002 Dec;12(6):471-7. doi: 10.1016/s1050-6411(02)00041-x.
When skeletal muscle is stretched during a tetanic contraction, the resulting force is greater than the purely isometric force obtained at the corresponding final length. Several mechanisms have been proposed to explain this phenomenon, but the most accepted mechanism is the sarcomere length non-uniformity theory. This theory is associated with the notion of instability of sarcomeres on the descending limb of the force-length relationship. However, recent evidence suggests that this theory cannot account solely for the stretch-induced force enhancement. Some of this evidence is presented in this paper, and a new mechanism for force enhancement is proposed: one that is associated with the engagement of a passive force during stretch. We speculate that this passive force enhancement may be caused by titin, a protein associated with passive force production at long sarcomere lengths.
当骨骼肌在强直收缩过程中被拉伸时，产生的力量大于在相应最终长度下获得的纯等长力量。已经提出了几种机制来解释这一现象，但最被认可的机制是肌节长度不均匀性理论。该理论与力-长度关系下降支上肌节的不稳定性概念相关。然而，最近的证据表明，该理论不能单独解释拉伸诱导的力量增强。本文给出了其中一些证据，并提出了一种新的力量增强机制：一种与拉伸过程中被动力的参与相关的机制。我们推测这种被动力增强可能是由肌联蛋白引起的，肌联蛋白是一种在长肌节长度下与被动力产生相关的蛋白质。
