AchillesTendon

The Achilles tendon is fibrous tissue that connects the heel to the muscles of the lower leg: the calf muscles. Leg muscles are the most powerful muscle group in the body and the Achilles tendon is the thickest and strongest tendon in the body. Contracting the calf muscles pulls the Achilles tendon, which pushes the foot downward. This contraction enables: standing on the toes, walking, running, and jumping. Each Achilles tendon is subject to a person’s entire body weight with each step. Depending upon speed, stride, terrain and additional weight being carried or pushed, each Achilles tendon may be subject to up to 3-12 times a person’s body weight during a sprint or push off.
http://www.achillestendon.com/