Imaging Studies of the Mechanical and Architectural Characteristics of the Human Achilles Tendon in Normal, Unloaded and Rehabilitating Conditions

Tendons are known to have a profound impact on the overall function of the musculoskeletal system in their role as a structural link and force transmitter between muscle and bone. Their unique viscoelastic response under tension allows efficient use and recycling of stored energy during stretch involved in locomotion, modulating joint position control, and providing protection from muscle injuries through reduction of mechanical oscillation and shock. The study of the mechanical behavior of the Achilles Tendon, defined as the thick or external tendon running from the calcaneus insertion to the distal part of the soleus muscle, is of particular clinical importance, since it is known to be the most likely site of tendon rupture and tear in humans. This chapter will review the known mechanical, architectural and biochemical characteristics of this tissue, vital for the transmission for force generated by the muscle fibers to the bone.