Tendonitis: Causes, Symptoms, and Treatment

Tendonitis (also spelled tendinitis) is an acute condition where the tendons that connect muscle to bone become inflamed. This inflammation can cause pain, loss of mobility in the tendon, and decreased strength in the muscle from which the tendon arises.

Tendons are fibrous cords of collagen that serve as flexible anchors in and around the joints of the body. They come in many shapes and sizes, from smalls ones which enable the movements of fingers, to larger ones, like the Achilles tendon, which help us stand or walk.

There are many reasons why a tendon can become inflamed and, when it does, it can often be painful. The pain tends to be felt most profoundly at the insertion site where the tendon attaches to the bone. It can also be strongly felt where the muscle and tendon connect.

While there are hundreds of tendons throughout the body, only a small handful are affected by tendonitis. These tendons tend to have fewer blood vessels servicing them, and the lack of blood supply hinders their ability to heal after injury. The parts of the tendon most impacted by this effect are called the watershed zones where the blood supply is at its weakest.

Direct injury—such as a blow to the tendon—can also cause tendonitis. Inflammatory disorders, such as rheumatoid arthritis and osteoarthritis, can also give rise to both the sudden (acute) and persistent (chronic) inflammations of tendons.

Tendonitis is more commonly seen in people over 40 with the risk and severity of symptoms typically increasing with age.

Tendonitis can happen almost anywhere on the body and is typically classified by its location. Because the condition is associated with the repetitive movement, we tend to see it in people who perform certain tasks by routine or who engage in specific sports activities. Some of the more common types include:

• Achilles tendonitis, involving the tendon between the calf muscle and heel
• Patellar tendonitis, sometimes referred to as jumper’s knees
• Elbow tendonitis, commonly known as tennis elbow or golfer's elbow
• Biceps tendonitis, involving the tendon between the bicep and shoulder
• Rotator cuff tendonitis, known as pitcher’s shoulder or swimmer’s shoulder
• Wrist tendonitis, sometimes called bowler’s wrist

Tendonitis is a characterized by the sudden appearance of pain and inflammation and should not be confused with tendinosis in which symptoms are chronic and persistent. In many cases, the appearance of symptoms will be abrupt, often associated with an injury or a period of excessive activity. At other times, the symptoms will appear gradually and worsen over time.

The most common features of tendonitis include:

• Swelling of the tendon, usually with redness and warmth
• Tenderness directly over the tendon
• Pain with the movement of the affected area
• A cracking or grating sensation when the joint is moved
• The appearance of a lump or bulge on the tendon itself
• Stiffness due to swelling

Diagnosis is typically made with a physical examination. If the cause is not clear or there are co-occurring conditions, the doctor may order additional tests. X-rays and magnetic resonance imaging (MRI) are generally less helpful in making a diagnosis and are really only used if there are concerns about a possible fracture or joint damage.

The treatment of tendonitis involves three elements:

• Restriction of movement of the affected tendon
• Reduction of inflammation
• Rehabilitation of the injured tendon, joint, and muscle which includes regaining normal tendon mobility and tolerance to loading.

To achieve this, the injured joint must first be immobilized to relieve any pressure on the afflicted tendon. Ice can be used in the initial days to reduce swelling and pain. Non-steroidal anti-inflammatory drugs, like ibuprofen, may also provide relief.

In people with tendinosis or recurrent tendonitis, corticosteroid injections may be used to provide short- to medium-term relief. Overuse should be avoided as it can weaken the tendon over time and increase the risk of rupture.

Treatment may be supported by physical therapy to manipulate and massage the affected area. Recovery tends to be faster, often with the recovery of the full range of motion.

In addition to physical therapy, a structured home fitness program can assist with the avoidance of tendonitis. One technique that seems particularly useful is a form of exercise called eccentric resistance training.

During everyday activities, our muscles work by contracting and releasing. The contraction is called a concentric action; the release is an eccentric action.

In eccentric resistance training, a muscle is contracted to lift a weight but then slowly released to maintain tension until the muscle is fully extended. This slow, eccentric action allows you build strength in and around the affected joint without placing undue stress on the tendon itself.

It is a system commonly used by athletes following a severe injury and has been found to beneficial to older adults who are less likely to be injured.

Tendonitis can be a painful condition that limits your ability to engage in your normal work or recreational activities. If you suspect you have tendonitis, check in with your physical therapist and get started on treatment right away.