Passive mechanical properties of human gastrocnemius muscle-tendon units, muscle fascicles and tendons in vivo
Passive mechanical properties of human gastrocnemius muscle-tendon units, muscle fascicles and tendons in vivo
复制标题
DOI：
10.1242/jeb.002204
复制
发表时间：
2007-12-01
影响因子：
2.8
通讯作者：
Gandevia, S. C.
中科院分区：
文献类型：
--
作者：
Hoang, P. D.;Herbert, R. D.;Gandevia, S. C.
这项研究提供了第一个在体内测量的被动长度张力特性的放松人体肌肉束和肌腱。采用一种新的方法，从一系列膝关节角度下获得的踝关节刚度测量值中推导出人腓肠肌肌腱单元的被动长度-张力特性。被动长度-张力曲线的肌肉肌腱单位，然后结合超声测量肌束长度和pennation，以确定被动长度-张力曲线的肌束和肌腱。肌束、肌腱和整个肌肉-肌腱单位的平均松弛长度分别为3.3 +/- 0.5 cm、39.5 +/- 1.6 cm和42.3 +/- 1.5 cm（平均值+/- s.d.，N=6）。平均而言，肌肉-肌腱单位在其范围的最短2.3 +/- 1.2 cm内松弛（即，其被动张力为零）。随着膝关节和踝关节角度的联合变化，腓肠肌肌腱单位长度超过松弛长度的最大增加为6.7 +/- 1.9 cm，其中52.4 +/- 11.7%是由于肌腱延长。在生理长度范围内，肌束和肌腱分别承受86.4 +/- 26.8%和9.2 +/-4.1%的应变。我们的结论是，放松的人腓肠肌肌腱单位福尔斯松弛超过约四分之一，其在体内的长度和肌束应变远大于肌腱应变。尽管如此，由于肌腱比肌束长得多，肌腱贡献了肌肉肌腱单元总顺应性的一半以上。
This study provides the first in vivo measures of the passive length-tension properties of relaxed human muscle fascicles and their tendons. A new method was used to derive passive length-tension properties of human gastrocnemius muscle-tendon units from measures of ankle stiffness obtained at a range of knee angles. Passive length-tension curves of the muscle-tendon unit were then combined with ultrasonographic measures of muscle fascicle length and pennation to determine passive length-tension curves of the muscle fascicles and tendons. Mean slack lengths of the fascicles, tendons and whole muscle-tendon units were 3.3 +/- 0.5 cm, 39.5 +/- 1.6 cm and 42.3 +/- 1.5 cm, respectively (means +/- s.d., N=6). On average, the muscle-tendon units were slack (i.e. their passive tension was zero) over the shortest 2.3 +/- 1.2 cm of their range. With combined changes of knee and ankle angles, the maximal increase in length of the gastrocnemius muscle-tendon unit above slack length was 6.7 +/- 1.9 cm, of which 52.4 +/- 11.7% was due to elongation of the tendon. Muscle fascicles and tendons underwent strains of 86.4 +/- 26.8% and 9.2 +/- 4.1%, respectively, across the physiological range of lengths. We conclude that the relaxed human gastrocnemius muscle-tendon unit falls slack over about one-quarter of its in vivo length and that muscle fascicle strains are much greater than tendon strains. Nonetheless, because the tendons are much longer than the muscle fascicles, tendons contribute more than half of the total compliance of the muscle-tendon unit.