Dynamic force responses of skeletal muscle during stretch-shortening cycles
Dynamic force responses of skeletal muscle during stretch-shortening cycles
复制标题
DOI：
10.1007/s00421-003-0849-8
复制
发表时间：
2003-09-01
影响因子：
3
通讯作者：
Cutlip, RG
中科院分区：
文献类型：
--
作者：
Geronilla, KB;Miller, GR;Cutlip, RG
由拉伸-缩短周期（即周期性偏心/同心肌肉动作）引起的肌肉损伤是体育和职业相关活动中主要关注的问题之一。整个肌肉的机械反应与神经运动单元、结缔组织和力产生机制的损伤有关。本研究的目的是引入一种新的方法来量化大鼠在损伤拉伸-缩短周期中骨骼肌力的实时变化。本研究选择雄性Sprague Dawley大鼠（n=24）。背屈肌组在体内使用测力仪和电刺激进行150次拉伸缩短周期（n=12）或15次等距收缩（n=12）。暴露于拉伸-缩短周期后的肌肉损伤通过48小时不可恢复的力量缺陷和肌纤维坏死的存在得到证实。通过将动态力特征分解为峰值力（F-peak）、最小力（F-min）、平均力（F-mean）和循环力（F-a），分析了拉伸-缩短周期中动态力的变化。第15组缩短拉伸周期后，缩短拉伸参数F-peak、F-min、F-mean和F-a下降了50% (P
Muscle damage due to stretch-shortening cycles (i.e., cyclic eccentric/concentric muscle actions) is one of the major concerns in sports and occupational related activities. Mechanical responses of whole muscle have been associated with damage in neural motor units, in connective tissues, and the force generation mechanism. The objective of this study was to introduce a new method to quantify the real-time changes in skeletal muscle forces of rats during injurious stretch-shortening cycles. Male Sprague Dawley rats (n=24) were selected for use in this study. The dorsi flexor muscle group was exposed to either 150 stretch-shortening cycles (n=12) or 15 isometric contractions (n=12) in vivo using a dynamometer and electrical stimulation. Muscle damage after exposure to stretch-shortening cycles was verified by the non-recoverable force deficit at 48 h and the presence of myofiber necrosis. Variations of the dynamic forces during stretch-shortening cycles were analyzed by decomposing the dynamic force signature into peak force (F-peak), minimum force (F-min), average force (F-mean), and cyclic force (F-a). After the 15th set of stretch-shortening cycles, the decrease in the stretch-shortening parameters, F-peak, F-min, F-mean, and F-a, was 50% (P