The Achilles is the largest tendon in the body and is located at the back of the lower leg. The American Academy of Family Physicians warns that the Achilles tendon is also the most susceptible to injury and damage due to over-use and its limited blood supply.
Structure
The Achilles tendon spans between the gastrocnemius and soleus muscles in the calf at the back of the lower leg and the calcaneous, or heel bone. The website Arthroscopy notes that this tendon lies just below the skin and can be felt below the ankle at the back of the foot.
The Achilles and other tendons in the body are composed of tendon fibers grouped into bundles. The entire tendon is wrapped in connective tissue called the paratenon. A bursa is a small fluid filled sac that reduces friction between bones and other structures. In the Achilles tendon, the retrocalcaneous bursa and subcutaneous calcaneal bursa reduce the friction between the tendon and heel bone as well as the overlying skin.
Function
The Achilles tendon allows the foot and the leg muscles to move in a wide range of motions. The tendon moves when the gastrocnemius muscle in the calf contracts or shortens. This causes the toes of the foot to point downwards, which is a necessary movement for normal walking, running, jumping, climbing stairs and standing on the toes, as explained by the website Arthroscopy.
Blood Supply
Blood flow to the Achilles tendon is provided through longitudinal arteries that pass through the muscles of the lower leg. The sports website Peak Performance notes that the area of the tendon above the calcaneous, or heel bone, receives a diminished amount of nourishing blood and hence is more susceptible to injury and damage, particularly with age.
Common Conditions
The Achilles tendon is vulnerable to injury in accidents, falls and high-velocity sports. Aging and normal wear-and-tear can also damage the tendon directly, as well as its related structures, such as the sheath, bursa and bone. The American Academy of Family Physicians notes that injury to the Achilles tendon can occur gradually or suddenly. Common conditions of this tendon include ruptures and inflammations such as tendonitis, retrotrocalcaneobursitis and peritendonitis.
Treatment
According to the American Academy of Family Physicians, healing injuries and damage to the Achilles tendon can take a long time, as there is limited blood supply to the area. A doctor can make an accurate diagnosis and plan the best mode of treatment. If the tendon or a related structure is inflamed, as occurs in tendonitis and retrocalcaneobursitis, the primary method of treatment is to ice the area, rest the tendon and take non-steroidal anti-inflammatory drugs. Physical therapy and orthotic or leg and foot braces may be required. If there is a rupture of the tendon, surgery or a cast is necessary for treatment.
