文章基本信息

标题：Residual force enhancement due to active muscle lengthening allows similar reductions in neuromuscular activation during position- and force-control tasks
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作者：Rhiannon Marion ; Geoffrey A. Power
期刊名称：Journal of Sport and Health Science
印刷版ISSN：2095-2546
出版年度：2020
卷号：9
期号：6
页码：670-676
DOI：10.1016/j.jshs.2020.07.003
出版社：Elsevier
摘要：Background Residual torque enhancement (rTE) is the increase in torque observed during the isometric steady state following active muscle lengthening when compared with a fixed-end isometric contraction at the same muscle length and level of neuromuscular activation. In the rTE state, owing to an elevated contribution of passive force to total force production, less active force is required, and there is a subsequent reduction in activation. In vivo studies of rTE reporting an activation reduction are often performed using a dynamometer, where participants contract against a rigid restraint, resisting a torque motor. rTE has yet to be investigated during a position task, which involves the displacement of an inertial load with positional control. Methods A total of 12 participants (6 males, 6 females; age = 22.8 ± 1.1 years, height = 174.7 ± 8.6 cm, mass = 82.1 ± 37.7 kg; mean ± SD) completed torque- and position-matching tasks at 60% maximum voluntary contraction for a fixed-end isometric contraction and an isometric contraction following active lengthening of the ankle dorsiflexors. Results There were no significant differences in activation between torque- and position-matching tasks ( p = 0.743), with ∼27% activation reduction following active lengthening for both task types ( p < 0.001). Conclusion These results indicate that rTE is a feature of voluntary, position-controlled contractions. These findings support and extend previous findings of isometric torque-control conditions to position-controlled contractions that represent different tasks of daily living.
关键词：Eccentric ; Electromyography ; History dependence of force ; Position tasks ; Residual force enhancement