Horses damp the spring in their step

Article

关键词: MUSCLE;    LOCOMOTION;    SIMULATION;    ENERGY;    STRAIN;    GASTROCNEMIUS;    BEHAVIOR;    STORAGE;    MODEL;   

DOI  :  10.1038/414895a

来源: SCIE

【 摘 要 】

The muscular work of galloping in horses is halved by storing and returning elastic strain energy in spring-like muscle-tendon units(1,2). These make the legs act like a child's pogo stick that is tuned to stretch and recoil at 2.5 strides per second. This mechanism is optimized by unique musculoskeletal adaptations: the digital flexor muscles have extremely short fibres and significant passive properties, whereas the tendons are very long and span several joints(3,4). Length change occurs by a stretching of the spring-like digital flexor tendons rather than through energetically expensive length changes in the muscle(5). Despite being apparently redundant for such a mechanism(5), the muscle fibres in the digital flexors are well developed. Here we show that the mechanical arrangement of the elastic leg permits it to vibrate at a higher frequency of 30-40 Hz that could cause fatigue damage to tendon and bone. Furthermore, we show that the digital flexor muscles have minimal ability to contribute to or regulate significantly the 2.5-Hz cycle of movement, but are ideally arranged to damp these high-frequency oscillations in the limb.

【 授权许可】

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