Mechanical properties of cat soleus muscle elicited by sequential ramp stretches: implications for control of muscle.
Mechanical properties of cat soleus muscle elicited by sequential ramp stretches: implications for control of muscle.
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连续斜坡拉伸引起的猫比目鱼肌的机械特性：对肌肉控制的影响。
DOI：
10.1152/jn.1993.70.3.997
复制
发表时间：
1993
影响因子：
2.5
通讯作者：
Rymer,WZ
中科院分区：
文献类型：
--
作者：
Lin,DC;Rymer,WZ
1.力的变化areflexive猫比目鱼肌在去大脑猫记录在响应两个连续的恒定速度（斜坡）拉伸，分开的可变的时间间隔，在此期间的长度保持不变。初始（即，预牵张）背景力通过激活交叉伸展反射产生，牵张反射通过切断同侧背根消除。2.对于第一次拉伸的初始400-900微米，肌肉表现出高刚度，经典地称为“短程刚度”。在这个高硬度区域之后，硬度突然降低，称为肌肉“屈服”，之后力量保持在相对恒定的水平，达到力量的平台。该平台力水平很大程度上取决于拉伸速度，但这种依赖性远小于与拉伸速度的增加成比例，因为速度增加10倍产生平台力增加< 2倍。3.在两个连续斜坡拉伸的速度相同的实验中，无论第二次拉伸之前经过的时间如何（从0到500 ms变化），每次拉伸的力平台水平都相同。相比之下，在第二次拉伸的初始部分期间的刚度的测量显示出时间依赖性的幅度减小。然而，在第一次拉伸完成后，刚度迅速恢复，在30-40 ms内恢复到对照值。在一个准备，其中两个连续的斜坡拉伸的速度是不同的，在第二个拉伸期间引起的力高原表现出速度依赖性与早期的单速度研究中记录的。此外，肌肉屈服仍然是明显的，在这种情况下，力的变化是由于速度的变化和短程刚度尚未完全恢复从初始拉伸。在这些研究结果的基础上，我们认为，短期刚度和产量的经典描述是不够的，在力的变化，通常被称为肌肉产量反映了短期之间的过渡，瞬态弹性行为的稳态，基本上是粘性的行为。5.为了检查在单斜坡拉伸过程中肌肉的机械刚度的变化，在恒定速度拉伸之前、期间和之后的不同时间叠加单个脉冲扰动。力增量引起的响应于每个脉冲相对于初始等距值减少，保持基本恒定，直到斜坡结束，然后返回到其预拉伸幅度后不久（30-40毫秒）拉伸终止。（400字处截断摘要）
1. Force changes in areflexive cat soleus muscle in decerebrate cats were recorded in response to two sequential constant velocity (ramp) stretches, separated by a variable time interval during which the length was held constant. Initial (i.e., prestretch) background force was generated by activating the crossed-extension reflex, and stretch reflexes were eliminated by section of ipsilateral dorsal roots. 2. For the initial 400-900 microns of the first stretch, the muscle exhibited high stiffness, classically termed "short-range stiffness." This high stiffness region was followed by an abrupt reduction in stiffness, called muscle "yield," after which force remained at a relatively constant level, achieving a plateau in force. This plateau force level depended largely on stretch velocity, but this dependence was much less than proportional to the increase in stretch velocity, in that a 10-fold increase in velocity produced < 2-fold increase in plateau force. 3. In experiments where the velocities of the two sequential ramp stretches were identical, the force plateau level was the same for each stretch, regardless of the time elapsed before the second stretch (varied from 0 to 500 ms). In contrast, measures of stiffness during the initial portion of the second stretch showed time-dependent magnitude reductions. However, stiffness recovered quickly after the first stretch was completed, returning to control values within 30-40 ms. 4. In one preparation, in which the velocities of the two sequential ramp stretches were different, the force plateau elicited during the second stretch exhibited velocity dependence comparable with that recorded in the earlier single velocity studies. Furthermore, muscle yield was still evident in the case where the force change was due solely to the change in velocity and where short-range stiffness had not yet recovered fully from the initial stretch. On the basis of these findings, we argue that the classical descriptions of short-range stiffness and yield are inadequate and that the change in force that has typically been called the muscle yield reflects a transition between short-range, transient elastic behavior to steady-state, essentially viscous behavior. 5. To examine changes in the muscle's mechanical stiffness during single ramp stretches, a single pulse perturbation was superimposed at various times before, during, and subsequent to the constant velocity stretch. The force increment elicited in response to each pulse decreased relative to the initial isometric value, remained essentially constant until the end of the ramp, and then returned to its prestretch magnitude shortly (30-40 ms) after stretch termination.(ABSTRACT TRUNCATED AT 400 WORDS)
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影响因子：
5.5
作者：
LOMBARDI, V;PIAZZESI, G
通讯作者：
PIAZZESI, G
影响因子：
5.5
作者：
FLITNEY, FW;HIRST, DG
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神经系统在肢体运动中控制哪些肌肉变量？
影响因子：
29.3
作者：
R. Stein
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R. Stein
蛙肌强直单纤维等速拉长过程中力增强的机制。
影响因子：
--
作者：
F. Colomo;V. Lombardi;G. Piazzesi
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G. Piazzesi
通过脊椎动物骨骼肌纤维强直收缩期间的拉伸来增强机械性能。
DOI：
--
发表时间：
1978
期刊：
Journal of Physiology
影响因子：
--
作者：
K. Edman;G. Elzinga;M. Noble
通讯作者：
M. Noble