Tendon is a highly organized connective tissue joining muscle to bone,
capable of resisting high tensile forces while transmitting forces fr
om muscle to bone. The dense, regularly arranged collagenous tissue is
made up of fibers, cells of various shapes and ground substance. The
mechanical and physiological characteristics of collagen (nearly 85% o
f the dry weight of tendon) dictate the qualities of tendon. In additi
on, tendon is flexible so that it can bend at joints, as well as actin
g as a damping tissue to absorb shock and limit potential damage to mu
scle (1). Tendon also shows a degree of extensibility. If the strain u
sed; to stretch a tendon could be recovered,a beneficial elastic effec
t would be achieved. Muscles lengthen and shorten in a cyclical manner
. During the lengthening period, elastic energy can be stored and used
as elastic recoil. For example, the Achilles tendon is stretched late
in the stance phase as the triceps surae muscles contract and the ank
le dorsiflexes. Prior to plantarflexion, muscle activation ceases and
stored energy helps to initiate planter flexion.