First, there's a pop or a snap. Then an immediate sharp pain in the back of your ankle and lower leg that makes it impossible to walk properly. It almost feels like you've been kicked, or even shot.

These are the sensations typical of an Achilles tendon rupture. The Achilles tendon is a large, strong fibrous cord that connects the muscles in the back of your lower leg to your heel bone.

If you overstretch your Achilles tendon, it can tear (rupture). An Achilles tendon rupture can be partial or complete. Usually an Achilles tendon rupture occurs just above your heel bone, but it can happen anywhere along the tendon.

Although other injuries affecting your Achilles tendon often improve with home treatment, an Achilles tendon rupture often requires surgical repair.

Signs and symptoms of an Achilles tendon rupture include:

• Pain, possibly severe, and swelling near your heel
• An inability to bend your foot downward or walk normally
• An inability to rise on your toes on the injured leg, if you've ruptured the tendon completely

Often people report hearing a popping or snapping sound when the injury occurs. With a partial rupture, you may still be able to move your foot, and you may experience only minor pain and swelling.

If you haven't torn your Achilles tendon, you may be experiencing other conditions involving your Achilles tendon, such as bursitis or tendinitis. Here's how they affect your Achilles tendon:

• Bursitis. Bursae — tiny sacs of fluid located throughout your body — cushion movement between bones and muscles and tendons attached to bones, facilitating movement by limiting friction. Bursitis is inflammation and irritation of a bursa. Inflammation can occur in the bursa between your heel bone (calcaneus) and your Achilles tendon. This type of bursitis is called retrocalcaneal bursitis.

  Bursitis involving the area where your Achilles tendon attaches to your heel bone usually begins with pain and irritation at the back of the heel. There may be visible redness and swelling in the area, and the back of your shoe may cause further irritation.

• Tendinitis. Achilles tendinitis is inflammation of your Achilles tendon. The pain is the result of tiny tears and inflammation in the tissue of the tendon itself. Tendinitis of the Achilles tendon usually develops just above the attachment point of the tendon to your heel bone. Signs and symptoms that you may have Achilles tendinitis include swelling, and pain when pushing off during walking or after periods of rest.

Your Achilles tendon helps you point your foot downward, rise on your toes and push off your foot as you walk. You rely on it virtually every time you move your foot. Injuries to your Achilles tendon — also called your heel cord — result from repeated stress on the tendon, which may be caused or aggravated by:

• Overuse
• Running on hills and hard surfaces
• Poor stretching habits
• Tight calf muscles
• Weak calf muscles
• Worn-out or ill-fitting shoes
• Flatfeet

Injuries to your Achilles tendon can often result from taking part in an activity involving stop-and-start footwork for which you're not conditioned or for which you haven't stretched properly. This might include playing tennis, racquetball or basketball for the first time after a long break.

Sometimes, though, injuries can occur from simply putting too much stress on your Achilles tendon in the course of a simple activity, such as gardening. Occasionally, even highly conditioned athletes may rupture an Achilles tendon.

As you age, the risk of Achilles tendon rupture may increase. If you don't exercise regularly, the Achilles tendon may weaken and become thin, making it more susceptible to injury.

See your doctor if you experience persistent pain near the back of your heel or in the area of your Achilles tendon, and especially if the pain doesn't greatly improve despite self-care measures.

See your doctor immediately if you experience signs or symptoms of an Achilles tendon rupture.

To diagnose Achilles tendon problems, your doctor will likely ask questions about your physical activities and perform an examination of your feet, ankles and legs. If it's clear that your Achilles tendon is ruptured, surgical repair will likely be considered.

If there's a question about a partial or complete rupture of your Achilles tendon, your doctor may order a magnetic resonance imaging (MRI) scan, a painless procedure that uses magnetic fields to create a computer image of the tissues of your body.

Treatment for Achilles tendon ruptures can be surgical or nonsurgical.

• Surgery. Surgery is a common treatment for a complete rupture of the Achilles tendon. The procedure generally involves making an incision in the back of your lower leg and stitching the torn tendon together. Depending on the condition of the torn tissue, the repair may be reinforced with other tendons.

  Afterward, you'll need to spend about six to eight weeks with your leg in a walking boot, cast, brace or splint. To promote healing and to avoid stretching the surgical repair, your foot may initially be pointed slightly downward in the boot or brace, and then moved gradually to a neutral position.

• Nonsurgical treatment. This approach typically involves wearing a cast or walking boot, which allows the ends of your torn tendon to reattach themselves on their own. This method can be effective, and it avoids the risks, such as infection, associated with surgery. However, the likelihood of re-rupture is higher with a nonsurgical approach, and recovery can take longer. If re-rupture occurs, surgical repair may be more difficult.

If you are very active and want to resume strenuous sports or recreational activities, surgical repair is usually preferable. Surgery is generally very effective, and your risk of complications is typically quite low. If you are less active or have a chronic illness, you may wish to opt for nonsurgical treatment, which precludes wound complications and exposure to anesthesia.

Rehabilitation
After treatment, whether surgical or nonsurgical, you'll go through a rehabilitation program involving physical therapy exercises to strengthen your leg muscles and Achilles tendon. Most people return to their former level of activity within four to six months. Recovery depends not only on the quality of the rehab program, but also on your commitment.

Click to Enlarge

Calf stretch exercise

To help prevent an Achilles tendon injury, gently stretch your Achilles tendon and calf muscles before taking part in physical activities. Perform stretching exercises slowly, stretching to the point at which you feel a noticeable pull, but not pain. Don't bounce during a stretch.

To further reduce your chance of developing Achilles tendon problems, follow these tips:

• Avoid activities that place excessive stress on your heel cords, such as hill-running and jumping activities (especially if done consistently).
• If you notice pain during exercise, rest.
• If one exercise or activity causes you persistent pain, try another.
• Alternate high-impact sports, such as running, with low-impact sports, such as walking, biking or swimming.
• Maintain a healthy weight.
• Wear well-fitting athletic shoes with proper cushioning in the heels.

Strengthening your calf muscles also can help prevent injury to your Achilles tendon. To strengthen your calf muscles, practice toe raises:

• Stand flat, then rise up on your toes.
• Hold the elevated position momentarily before slowly dropping back down to a stand. Emphasizing the slow return to the ground will help improve the force-absorbing capability of your calf muscle and Achilles tendon.
• Start with raising just your body weight. Later, you can add hand weights as you do this exercise or raise your body weight on just one foot.

To avoid a recurrence of an Achilles tendon injury, follow these guidelines:

• Use warm-up and cool-down exercises and calf-strengthening exercises.
• Apply ice to your Achilles tendon after exercise.
• Alternate high-impact sports with low-impact sports, so as not to overwork your Achilles tendons.

If you experience any of the signs and symptoms of Achilles tendon rupture — are unable to rise on your toes, have difficulty bearing weight due to pain or have noticeable swelling in the region of your tendon — see your doctor. A rupture should be treated by a professional, not by self-care measures at home.