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.
Causes of Injury
Overuse, misalignment, improper footwear, medication side effects, and/or accidents can all result in Achilles tendon injuries. Multiple causes often contribute to the same Achilles tendon injury.
The best way to prevent an Achilles tendon injury is to a) stay in overall good shape, and b) warm-up, stretch, and strengthen the Achilles tendons. The best way to prevent an Achilles tendon injury from getting worse is to address the injury immediately: it will get worse if not addressed.
Undue strain results in over 230,000 Achilles tendon injuries per year in the U.S. alone. The undue strain could be caused by a variety of factors, including: tightness or weakness of the leg, knee, hip, or back; high or low arches; uneven leg lengths; alternating between high (2”) heels and exercise shoes; and/or sudden (rather than gradual) increases in training, such as running faster, further, or up steeper hills.
The most common Achilles tendon injuries are Achilles tendinosis (formerly called Achilles tendonitis) and Achilles tendon rupture. Achilles tendinosis is a soreness and stiffness that comes on gradually and continues to worsen until treated. It often starts with stiffness and creaking when first getting out of bed in the morning. Lightly pinching the Achilles tendon with the forefinger and thumb will indicate soreness. Achilles tendinosis is a common injury among middle and long distance runners. Achilles tendon rupture is a partial or complete tear of the Achilles tendon. It comes on suddenly, sometimes with a popping sound, and is debilitating. Partial and full Achilles tendon ruptures are most likely to occur in sports requiring sudden eccentric stretching, such as sprinting and racquet sports. Partial Achilles tendon tears are also common among middle and long distance runners. Achilles tendon ruptures are most likely to occur to middle age athletes who have not been training or who have been doing relatively little training. It is sometimes difficult to distinguish between Achilles tendinosis and a partial Achilles tendon tear. Consult a physician to be sure.
Treatment for Achilles tendinosis includes: relative rest, muscle strengthening, physical therapies (i.e. ultrasound, laser photostimulation, electrical stimulation), and ice. Treatment for an Achilles rupture includes complete immobilization, or in the most severe cases: surgery.