While playing sports or doing aerobic exercises that require the body to momentarily leave the ground, the calf muscles are powerhouses of propulsion. In order for the calves to deliver a contraction forceful enough to make you airborne, the Achilles tendon rapidly stretches and then shortens like an elastic band. Do not ignore pain in the Achilles during exercise if you intend to stay active.
Anatomy and Function
Found at the base of the posterior lower leg, the Achilles tendon attaches the large gastrocnemius muscle of the calf to the calcaneus, or heel bone. The Achilles tendon works in conjunction with the gastrocnemeus to plantar flex the ankle, causing the toes to point downward away from the shin, the same action that enables you to rise up on your toes. During plyometric, or repetitive bounding activity, the Achilles tendon shortens with the gastrocnemeus to propel the entire weight of the body into the air, then maximally stretches in the grounding phase in preparation for rebound.
Tendinitis and Tendinopathy
Tendinitis refers to painful inflammation in a tendon, often due to repetitive motion. In the Achilles tendon, it can manifest at the attachment to the calcaneus or farther up, near the muscle. If left untreated and ignored, tendinitis of the Achilles can lead to a chronic condition called tendinopathy. Tendinopathy is a noninflammatory condition that is marked by degenerated tissue and a loss of normal fiber structure. Achilles tendinopathy may become a functional disability later in life.
Tear or Rupture
Small tears to the fascia, the fibrous outer casing of the muscle and tendon, are common in sports and manifest as delayed onset muscle soreness that goes away after a couple of days. But more serious and painful tears that penetrate the muscle fiber and ruptures that separate fibers need proactive treatment if they are to heal fully. The Achilles is the most commonly ruptured tendon, particularly among middle-aged men during sporting activities. Infrequency of physical activity, inadequate warm-up and failure to regularly stretch the calf muscles are all contributing factors.
Prevention and Rehabilitation
The most important and most commonly underestimated protective measure you can take to avoid injury to the Achilles tendon is to invest in a good pair of athletic shoes that provide support and shock absorption specific to the activities in which you regularly engage. Shoes used for court sports are designed differently than running shoes. If you enjoy a variety of activities, you may need more that one pair of shoes to fully protect you from injury during play. Because the Achilles tendon has a poor blood supply, injuries can be slow to heal. Applying the PRICE principle --- protect, rest, ice, compression and elevation --- may be adequate treatment for moderate tendinitis. Tears and ruptures may require medical intervention that could include casting or even surgery.
