The series-elastic shock absorber: tendons attenuate muscle power during eccentric actions
The series-elastic shock absorber: tendons attenuate muscle power during eccentric actions
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DOI：
10.1152/japplphysiol.01272.2009
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发表时间：
2010-08-01
影响因子：
3.3
通讯作者：
Azizi, Emanuel
中科院分区：
文献类型：
--
作者：
Roberts, Thomas J.;Azizi, Emanuel
李建军，李建军，李建军，等。弹性减震器的研究进展。中国生物医学工程学报（英文版），2009(5):396- 396。首次发表于2010年5月27日；doi: 10.1152 / japplphysiol.01272.2009。-弹性肌腱在运动过程中可以起到肌肉力量放大器或节能弹簧的作用。我们使用原位肌肉-肌腱准备来检查肌腱在延长收缩时的机械功能，当肌肉吸收能量时。测量了野生火鸡腓肠肌外侧肌的力、长度和力量。声压测量法用于测量肌束长度独立于肌腱单元（MTU）长度，由肌肉杠杆系统（伺服电机）测量。在完全激活的肌肉中，将一系列不同速度的斜坡拉伸应用于MTU。束束长度的变化与伺服电机施加在MTU上的长度变化解耦。在大多数情况下，肌束平均缩短，而MTU延长。在最快的拉伸过程中，MTU的能量输入为-54.4 J/kg，而在此期间肌肉束的估计功输入仅为-11.24 J/kg。这种差异表明，能量首先被弹性元件吸收，然后在收缩的延长阶段后释放出来对肌束做功。弹性元件对能量的临时储存也导致了肌束输入能量的显著衰减。在最快的延长速率下，MTU的峰值瞬时功率输入达到-2,143.9 W/kg，而束的峰值功率输入仅为-557.6 W/kg。这些结果表明，在能量吸收收缩过程中，肌腱可以通过限制峰值肌肉力量、延长率和功率输入来起到机械缓冲的作用。
Roberts TJ, Azizi E. The series-elastic shock absorber: tendons attenuate muscle power during eccentric actions. J Appl Physiol 109: 396-404, 2010. First published May 27, 2010; doi:10.1152/japplphysiol.01272.2009.-Elastic tendons can act as muscle power amplifiers or energy-conserving springs during locomotion. We used an in situ muscle-tendon preparation to examine the mechanical function of tendons during lengthening contractions, when muscles absorb energy. Force, length, and power were measured in the lateral gastrocnemius muscle of wild turkeys. Sonomicrometry was used to measure muscle fascicle length independently from muscle-tendon unit (MTU) length, as measured by a muscle lever system (servomotor). A series of ramp stretches of varying velocities was applied to the MTU in fully activated muscles. Fascicle length changes were decoupled from length changes imposed on the MTU by the servomotor. Under most conditions, muscle fascicles shortened on average, while the MTU lengthened. Energy input to the MTU during the fastest lengthenings was -54.4 J/kg, while estimated work input to the muscle fascicles during this period was only -11.24 J/kg. This discrepancy indicates that energy was first absorbed by elastic elements, then released to do work on muscle fascicles after the lengthening phase of the contraction. The temporary storage of energy by elastic elements also resulted in a significant attenuation of power input to the muscle fascicles. At the fastest lengthening rates, peak instantaneous power input to the MTU reached -2,143.9 W/kg, while peak power input to the fascicles was only -557.6 W/kg. These results demonstrate that tendons may act as mechanical buffers by limiting peak muscle forces, lengthening rates, and power inputs during energy-absorbing contractions.