Ferris D P, Louie M, Farley C T
Department of Integrative Biology, University of California, Berkeley 94720-3140, USA.
Proc Biol Sci. 1998 Jun 7;265(1400):989-94. doi: 10.1098/rspb.1998.0388.
A running animal coordinates the actions of many muscles, tendons, and ligaments in its leg so that the overall leg behaves like a single mechanical spring during ground contact. Experimental observations have revealed that an animal's leg stiffness is independent of both speed and gravity level, suggesting that it is dictated by inherent musculoskeletal properties. However, if leg stiffness was invariant, the biomechanics of running (e.g. peak ground reaction force and ground contact time) would change when an animal encountered different surfaces in the natural world. We found that human runners adjust their leg stiffness to accommodate changes in surface stiffness, allowing them to maintain similar running mechanics on different surfaces. These results provide important insight into mechanics and control of animal locomotion and suggest that incorporating an adjustable leg stiffness in the design of hopping and running robots is important if they are to match the agility and speed of animals on varied terrain.
奔跑的动物会协调其腿部许多肌肉、肌腱和韧带的动作，以便在与地面接触时，整个腿部的表现就像一个单一的机械弹簧。实验观察表明，动物腿部的刚度与速度和重力水平均无关，这表明它是由内在的肌肉骨骼特性决定的。然而，如果腿部刚度是不变的，那么当动物在自然界中遇到不同表面时，奔跑的生物力学（例如，地面反作用力峰值和地面接触时间）就会发生变化。我们发现，人类跑步者会调整其腿部刚度以适应表面刚度的变化，从而使他们在不同表面上保持相似的跑步力学。这些结果为动物运动的力学和控制提供了重要的见解，并表明如果跳跃和奔跑机器人要在不同地形上匹配动物的敏捷性和速度，在其设计中纳入可调节的腿部刚度很重要。
