An Achilles tendon injury results from a stretch, tear, or irritation to the tendon connecting the calf muscle to the back of the heel. These injuries can be so sudden and agonizing that they have been known to bring down charging professional football players in shocking fashion.

The most common cause of Achilles tendon tears is a problem called tendinitis, a degenerative condition caused by aging or overuse. When a tendon is weakened, trauma can cause it to rupture. (See illustration "Lateral View of the Ankle.")

Achilles tendon injuries are common in middle-aged "weekend warriors" who may not exercise regularly or take time to stretch properly before an activity. Among professional athletes, most Achilles injuries seem to occur in quick-acceleration, jumping sports like football and basketball, and almost always end the season's competition for the athlete.

Achilles tendon rupture is a common injury in athletes. It often presents with sudden onset of pain associated with a snapping sound in the lower leg. Patients often describe this sensation as having been kicked or shot in the lower leg. The injury is often disabling, and ambulation is difficult. Even standing up can be associated with unsteadiness. Achilles tendon injuries typically tend to occur in individuals who are only active intermittently. When the injury occurs, it is immediately disabling.

Etiology

Causes of Achilles tendon rupture include sudden forced plantar flexion of the foot, direct trauma, and long-standing paratendonitis. Sports that are often associated with Achilles tendon rupture include diving, tennis, basketball, and track. Risk factors for a rupture of the Achilles tendon include poor conditioning before exercise, prolonged use of corticosteroids, over exertion, and the use of quinolone antibiotics. The Achilles tendon rupture usually tends to occur about two to four cm above the calcaneal insertion of the tendon. In individuals who are right-handed, the left Achilles tendon is most likely to rupture and vice versa.

The exact cause of Achilles tendon injury appears to be multifactorial. The injury is most common in cyclists, runners, volleyball players, and gymnasts. When the ankle is subject to extreme pronation, it places enormous stress on the tendon, leading to injury. In cyclists, the combination of low saddle height and extreme dorsiflexion during pedaling may also be a factor in an overuse injury.

Systemic Factors

Systemic diseases that may be associated with Achilles tendon injuries include the following:

• Chronic renal failure

• Collagen deficiency

• Diabetes Mellitus

• Gout

• Infections

• Lupus

• Parathyroid disorders

• Rheumatoid arthritis

• Thyroid disorders

Foot problems that increase the risk of Achilles tendon injuries include the following:

• Cavus foot

• Insufficient gastrocsoleus flexibility and strength

• limited ability to perform ankle dorsiflexion

• Tibia vara

• Varus alignment with functional hyperpronation

It has been observed that Achilles tendon rupture is often more common in people with blood group O. Further anyone with a family history is also at a high risk of developing Achilles tendon rupture at some point in their life.

Epidemiology

The incidence rates of Achilles tendinosis varies from 6-18% in athletes. Football players are the least likely to develop this problem compared to gymnasts and tennis players. It is believed that about a million athletes suffer from Achilles tendon injuries each year. The true incidence of Achilles tendinosis is unknown, although reported incidence rates are 7% to 18% in runners, 9% in dancers, 5% in gymnasts, 2% in tennis players, and less than 1% in American football players. It is estimated that Achilles disorders affect approximately 1 million athletes per year.

The incidence of Achilles tendon injuries is on the increase in the USA because of more participation of people into sporting activities. Outside the USA, the exact incidence of Achilles tendon injuries are not known, but studies from Denmark and Scotland reveal 6-37 cases per 100,000 persons.

Achilles tendon injuries appear to be more common in males, and this is probably related to greater participation in sports activities. Most injuries are seen in between the third and fifth decade of life. Many of these individuals are only active intermittently and rarely warm up.

Calcaneal Tendon (also, Achilles tendon) strong tendon that inserts into the calcaneal bone of the ankle

The lateral compartment of the leg includes two muscles: the fibularis longus (peroneus longus) and the fibularis brevis (peroneus brevis). The superficial muscles in the posterior compartment of the leg all insert onto the calcaneal tendon (Achilles tendon), a strong tendon that inserts into the calcaneal bone of the ankle. The muscles in this compartment are large and strong and keep humans upright. The most superficial and visible muscle of the calf is the gastrocnemius. Deep to the gastrocnemius is the wide, flat soleus. The plantaris runs obliquely between the two; some people may have two of these muscles, whereas no plantaris is observed in about seven percent of other cadaver dissections. The plantaris tendon is a desirable substitute for the fascia lata in hernia repair, tendon transplants, and repair of ligaments. There are four deep muscles in the posterior compartment of the leg as well: the popliteus, flexor digitorum longus, flexor hallucis longus, and tibialis posterior.

Muscles of the Lower Leg

The muscles of the anterior compartment of the lower leg are generally responsible for dorsiflexion, and the muscles of the posterior compartment of the lower leg are generally responsible for plantar flexion. The lateral and medial muscles in both compartments invert, evert, and rotate the foot.

People with tendinitis often have tenderness at the point where the patellar tendon meets the bone. In addition, they may feel pain during running, hurried walking, or jumping. A complete rupture of the quadriceps or patellar tendon is not only painful, but also makes it difficult for a person to bend, extend, or lift the leg against gravity.

If there is not much swelling, the doctor will be able to feel a defect in the tendon near the tear during a physical examination. An x ray will show that the patella is lower than normal in a quadriceps tendon tear and higher than normal in a patellar tendon tear. The doctor may use an MRI to confirm a partial or total tear.

How Are Sports Injuries Treated?

Although using the RICE technique described previously can be helpful for any sports injury, RICE is often just a starting point. Here are some other treatments your doctor or other health care provider may administer, recommend, or prescribe to help your injury heal.

All medicines can have side effects. Some medicines and side effects are mentioned in this publication. Some side effects may be more severe than others. You should review the package insert that comes with your medicine and ask your health care provider or pharmacist if you have any questions about the possible side effects.

Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)

The moment you are injured, chemicals are released from damaged tissue cells. This triggers the first stage of healing: inflammation (see box "The Body's Healing Process"). Inflammation causes tissues to become swollen, tender, and painful. Although inflammation is needed for healing, it can actually slow the healing process if left unchecked.

To reduce inflammation and pain, doctors and other health care providers often recommend taking an over-the-counter nonsteroidal anti-inflammatory drug (NSAID) such as aspirin, ibuprofen, or naproxen sodium. For more severe pain and inflammation, doctors may prescribe one of several dozen NSAIDs available in prescription strength.

Though not an NSAID, another commonly used OTC medication, acetaminophen, may relieve pain. It has no effect on inflammation, however.

Warning: Side effects of NSAIDs include stomach problems; skin rashes; high blood pressure; fluid retention; and liver, kidney, and heart problems. The longer a person uses NSAIDs, the more likely he or she is to have side effects, ranging from mild to serious. Many other drugs cannot be taken when a patient is being treated with NSAIDs, because NSAIDs alter the way the body uses or eliminates these other drugs. Check with your health care provider or pharmacist before you take NSAIDs. NSAIDs should only be used at the lowest dose possible for the shortest time needed.

Immobilization

Immobilization is a common treatment for musculoskeletal sports injuries that may be done immediately by a trainer or paramedic. Immobilization involves reducing movement in the area to prevent further damage. By enabling the blood supply to flow more directly to the injury (or the site of surgery to repair damage from an injury), immobilization reduces pain, swelling, and muscle spasm and helps the healing process begin. Following are some devices used for immobilization:

• Slings, to immobilize the upper body, including the arms and shoulders.
• Splints and casts, to support and protect injured bones and soft tissue. Casts can be made from plaster or fiberglass. Splints can be custom made or ready made. Standard splints come in a variety of shapes and sizes and have Velcro straps that make them easy to put on and take off or adjust. Splints generally offer less support and protection than a cast, and therefore may not always be a treatment option.
• Leg immobilizers, to keep the knee from bending after injury or surgery. Made from foam rubber covered with fabric, leg immobilizers enclose the entire leg, fastening with Velcro straps.

Surgery

In some cases, surgery is needed to repair torn connective tissues or to realign bones with compound fractures. The vast majority of musculoskeletal sports injuries, however, do not require surgery.

Rehabilitation (Exercise)

A key part of rehabilitation from sports injuries is a graduated exercise program designed to return the injured body part to a normal level of function.

With most injuries, early mobilization-getting the part moving as soon as possible-will speed healing. Generally, early mobilization starts with gentle range-of-motion exercises and then moves on to stretching and strengthening exercises when you can without increasing pain. For example, if you have a sprained ankle, you may be able to work on range of motion for the first day or two after the sprain by gently tracing letters with your big toe. Once your range of motion is fairly good, you can start doing gentle stretching and strengthening exercises. When you are ready, weights may be added to your exercise routine to further strengthen the injured area. The key is to avoid movement that causes pain.

As damaged tissue heals, scar tissue forms, which shrinks and brings torn or separated tissues back together. As a result, the injury site becomes tight or stiff, and damaged tissues are at risk of reinjury. That's why stretching and strengthening exercises are so important. You should continue to stretch the muscles daily and as the first part of your warm-up before exercising.

When planning your rehabilitation program with a health care professional, remember that progression is the key principle. Start with just a few exercises, do them often, and then gradually increase how much you do. A complete rehabilitation program should include exercises for flexibility, endurance, and strength; instruction in balance and proper body mechanics related to the sport; and a planned return to full participation.

Throughout the rehabilitation process, avoid painful activities and concentrate on those exercises that will improve function in the injured part. Don't resume your sport until you are sure you can stretch the injured tissues without any pain, swelling, or restricted movement, and monitor any other symptoms. When you do return to your sport, start slowly and gradually build up to full participation. For more advice on how to prevent injuries as you return to active exercise, see the box "Tips for Preventing Injury."

Rest

Although it is important to get moving as soon as possible, you must also take time to rest following an injury. All injuries need time to heal; proper rest will help the process. Your health care professional can guide you regarding the proper balance between rest and rehabilitation.

Other Therapies

Other therapies used in rehabilitating sports injuries include:

• Cold/cryotherapy: Ice packs reduce inflammation by constricting blood vessels and limiting blood flow to the injured tissues. Cryotherapy eases pain by numbing the injured area. It is generally used for only the first 48 hours after injury.
• Heat/thermotherapy: Heat, in the form of hot compresses, heat lamps, or heating pads, causes the blood vessels to dilate and increase blood flow to the injury site. Increased blood flow aids the healing process by removing cell debris from damaged tissues and carrying healing nutrients to the injury site. Heat also helps to reduce pain. It should not be applied within the first 48 hours after an injury.
• Ultrasound: High-frequency sound waves produce deep heat that is applied directly to an injured area. Ultrasound stimulates blood flow to promote healing.
• Massage: Manual pressing, rubbing, and manipulation soothe tense muscles and increase blood flow to the injury site.

Most of these therapies are administered or supervised by a licensed health care professional.

Whether you've never had a sports injury and you're trying to keep it that way or you've had an injury and don't want another, the following tips can help.

• Avoid bending knees past 90 degrees when doing half knee bends.
• Avoid twisting knees by keeping feet as flat as possible during stretches.
• When jumping, land with your knees bent.
• Do warm-up exercises not just before vigorous activities like running, but also before less vigorous ones such as golf.
• Don't overdo.
• Do warm-up stretches before activity. Stretch the Achilles tendon, hamstring, and quadriceps areas and hold the positions. Don't bounce.
• Cool down following vigorous sports. For example, after a race, walk or walk/jog for 5 minutes so your pulse comes down gradually.
• Wear properly fitting shoes that provide shock absorption and stability.
• Use the softest exercise surface available, and avoid running on hard surfaces like asphalt and concrete. Run on flat surfaces. Running uphill may increase the stress on the Achilles tendon and the leg itself.