Running springs: speed and animal size.
Running springs: speed and animal size.
复制标题
DOI：
--
复制
发表时间：
1993-12
期刊：
影响因子：
--
通讯作者：
C. T. Farley;James W. Glasheen;Thomas A Mcmahon
中科院分区：
文献类型：
--
作者：
C. T. Farley;James W. Glasheen;Thomas A Mcmahon
小跑和跳跃的动物利用肌肉、肌腱和韧带在地面上弹跳时储存和返回弹性能量。我们研究肌肉骨骼弹簧系统在不同速度和不同大小的动物中是如何运作的。我们将小跑和跳跃建模为一个简单的弹簧-质量系统，它由一个腿弹簧和一个质量组成。我们发现，在狗、山羊、马和红袋鼠中，腿弹簧的刚度（k（腿））几乎与速度无关。当这些动物跑得更快或跳得更快时，腿弹簧在站立阶段扫过更大的角度，并且在接触地面阶段质心的垂直偏移减小。弹簧系统的这些变化使动物以更高的速度从地面上弹跳得更快。对各种体型动物（0.1-140公斤）在同等速度下的分析表明，体型较大的动物有更硬的腿弹簧（k（腿）[符号：见文本]M0.67，其中M为身体质量），但腿弹簧扫过的角度几乎与身体质量无关。因此，在大型动物中，弹簧-质量系统垂直振动的共振周期更长。脚与地面接触的时间长度随着身体质量的增加而增加，其方式与垂直振动的共振周期几乎相同。
Trotting and hopping animals use muscles, tendons and ligaments to store and return elastic energy as they bounce along the ground. We examine how the musculoskeletal spring system operates at different speeds and in animals of different sizes. We model trotting and hopping as a simple spring-mass system which consists of a leg spring and a mass. We find that the stiffness of the leg spring (k(leg)) is nearly independent of speed in dogs, goats, horses and red kangaroos. As these animals trot or hop faster, the leg spring sweeps a greater angle during the stance phase, and the vertical excursion of the center of mass during the ground contact phase decreases. The combination of these changes to the spring system causes animals to bounce off the ground more quickly at higher speeds. Analysis of a wide size range of animals (0.1-140 kg) at equivalent speeds reveals that larger animals have stiffer leg springs (k(leg) [symbol: see text] M0.67, where M is body mass), but that the angle swept by the leg spring is nearly independent of body mass. As a result, the resonant period of vertical vibration of the spring-mass system is longer in larger animals. The length of time that the feet are in contact with the ground increases with body mass in nearly the same way as the resonant period of vertical vibration.