By: Robert H. Sheinberg, D.P.M., D.A.B.F.A.S., F.A.C.F.A.S.

Overuse injuries to the muscle-tendon unit are common occurrences in the workplace. Tendons connect muscles to bones and are responsible for the movement of bones and joints. Collagen is the main component of tendons. When a tendon and its covering (sheath) becomes inflamed, it is commonly referred to as TENDONITIS.

Workers in high force, high repetition jobs have a greater incidence of tendonitis than low force, low repetition. This may be especially true if the worker is unaccustomed to the task. High repetition and forces over a prolonged period of time may result in microtears, chronic inflammation, and degeneration of tendons, often leading to tendon ruptures. With age, the strength of tendons begins to decrease, thus older workers starting a new task may be more susceptible to tendon injuries. Training results in increased tensile strength and collagen content in tendons, therefore, a slow, steady increase in workload is necessary to avoid inflammation of the tendon and
it's sheath.

Acute problems will often present with pain with movement of the body part. A crackling sensation may be felt with the movement of the inflamed tendon. Occasionally swelling will develop over the inflamed area. The area will always be very tender to light touch.

Chronic injuries develop when acute problems are not addressed. Often the injured area will be stiff with early movements and as blood goes to the area, the injured part may slightly improve. With repetitive stress to the area, the pain will redevelop and if chronic stresses are not addressed, the pain will be present at all times, even with movement of the body part at rest.

The best treatment is always prevention. Identifying why the injury occurred is of primary importance. Was it the type of job, repetitive force, amount of force that caused the injury, or was it too abrupt an increase in an activity or did an acute injury take place?

When an inflammatory condition to a tendon occurs, the patient must immediately stop the action that caused it and rest the injured area. Other tasks may be substituted that will not stress the injured tendon. Once a diagnosis has been made, physical therapy is ideally suited to reduce the inflammation. Splinting the injured area will also assist in diminishing daily stress to the area, thus allowing the inflammation to subside. Once the inflammation is decreased to a tolerable level, slowly increasing the range of motion to the injured area, followed by increasing strength of the muscle-tendon unit will limit recurrences.

Occasionally, anti-inflammatories may be used to assist in healing the injured tendon. If unresponsive to physical therapy and anti-inflammatories, placing the patient in a fiberglass cast will often put the tendon to complete rest and allow healing to take place. This will be followed by therapy to restore range of motion and to improve muscle strength.

MRI picture of Achilles tendonitis with thickening and small partial tear 


MRI of PT Tendon that is diseased. The tendon should be a thick black oval. The tendon has discontinuity and is thickened consistent with PTTD.