“THE HORSE'S AMAZING LEG”

Vocabulary:

1. gallop – fast run
2. energy – power needed to move
3. muscles – parts of the body that help it move
4. tendons – cords that connect muscles to bones
5. design – a special way something is made

A horse (Equus caballus) can gallop, reaching speeds of up to 30 miles per hour (50 km/h). Even though running takes a lot of effort, a horse does not use much energy. How is this possible? The secret is in the special way its legs work. When a horse runs, its legs do something incredible. The muscles and tendons in the legs take in energy when the hoof hits the ground. Then, like a spring, they release that energy to push the horse forward. This helps the horse move quickly without getting too tired.

Also, when a horse runs fast, its legs shake, which could hurt the tendons. But the muscles in its legs stop the shaking, keeping the tendons safe. Scientists call this a "special muscle-tendon design" because it gives the horse both speed and strength.

Engineers want to copy how a horse’s legs work to make robots with four legs. However, scientists at the Biomimetic Robotics Laboratory at the Massachusetts Institute of Technology say it is very hard to copy this design with the materials and knowledge we have today.