A
Horse can gallop at a speed of up to
30 miles per hour (50 km/h). Although
this involves considerable mechanical work, relatively little energy is spent.
How is this possible? The secret is in the horse’s legs.
Consider
what occurs when a horse gallops. Elastic muscle-tendon units absorb energy
when the leg steps onto the ground, and much like a spring, they return it,
propelling the horse forward.
Furthermore,
at a gallop the horse’s legs vibrate at high frequencies that could injure its
tendons. However, the muscles in the legs act as dampers. Researchers call this
structure a “highly specialized muscle-tendon design” that provides both
agility and strength.
Engineers
are trying to imitate the design of the horse’s legs for use in four-legged
robots. However, according to the Biomimetic Robotics Laboratory of the
Massachusetts Institute of Technology, the complexity of this design cannot be
easily duplicated with current materials and engineering knowledge.
