Tendons are fibrous tissues that connect muscles with bone. The Achilles tendon is the largest tendon in the body. It connects the calf muscles at the back of the leg with the heel, and facilitates movements such as jumping, running, and walking. 

Because the Achilles tendon is engaged so frequently and bears a great deal of pressure and stress throughout the day, it can become injured. Achilles tendon injuries cause the tissue to become irritated, inflamed, and swollen. Pain can come on gradually or be immediate, and will vary from mild to severe depending upon the injury. Where the pain occurs will vary as well, from just above the heel up through the back of the leg. There may also be stiffness in the tendon.

Achilles tendon injuries can often be caused by repetitive stress. They may also occur while running, playing tennis, gymnastics, football, basketball, dancing, soccer, baseball or other sports that require speeding up, slowing down, or pivoting quickly. Wearing high heels, falling from an elevation, stepping in a hole, having flat feet, bone spurs, tight leg muscles or tendons, wearing improper athletic shoes, exercising on uneven surfaces, or starting a new type of exercise can also cause Achilles tendon injuries.

The two most common Achilles tendon injuries are tendonitis and ruptures. Tendonitis causes painful inflammation and can occur in different parts of the tendon. Non-insertional Achilles tendonitis occurs when the fibers in middle of the tendon begin to break down, thicken, and swell. This condition typically affects younger, more active adults. Insertional Achilles tendonitis occurs where the tendon inserts into the heel bone. It is common for bone spurs to form with this type of injury. This condition can affect people of any age and level of activity.

Achilles tendon ruptures are a tear in the tendon. These breaks may be partial or complete. There may be an audible popping noise at the moment of injury and the pain will be sudden and severe.

An Achilles tendon injury can be diagnosed by your podiatrist after they examine you, check your range of motion, and possibly perform a calf squeeze test or review an X-ray or MRI. Depending on the type and severity of your injury, your podiatrist may treat your condition with rest/ice/compression/elevation (RICE), nonsteroidal anti-inflammatory medications, heel lifts, and stretching and strengthening exercises. If you have torn your Achilles tendon, treatment may include physical therapy, ultrasound, shockwave therapy, or possibly even surgery.