Overuse of a tendon most commonly results in tendon inflammation or tenosynovitis or tendonitis.
Tendonitis or tendinitis = inflammation of a tendon.
Tenosynovitis means inflammation of the sheath that surrounds the affected tendon.
These conditions can often happen together.
Your tendons are strong tissue that attaches a muscle to a bone. Most are covered by a sheath called the
synovium. This makes an oily fluid which lies between the tendon and the sheath. This helps the tendon move smoothly when it pulls on the bone it is attached to.
Symptoms
People normally describe pain, tenderness and swelling over the affected part of the tendon.
The skin can feel warm around the tendon. The movement of that part of the body near the tendon is reduced.
This can last weeks or months if it goes untreated.
Common areas affected
Wrists and hands are often the areas most affected. Below are some named conditions.
De Quervain tenosynovitis.
The tendons that straighten the thumb are affected. People often find they have pain over the wrist and the base of the thumb. This is made worse by activity, and improves with rest.
Trigger finger.
The ring finger is the most commonly affected finger. The finger normally doesn't straighten easily due to the inflammation.
Achilles tendonitis.
The Achilles tendon is above the heel.
Rotator cuff tendonitis.
The rotator cuff muscles are found at your shoulder. They help to rotate and lift your shoulder. The tendons from these muscles sometimes become inflamed.
Causes
Many cases happen for no obvious reason. Often it is due to overuse of the tendon.
Tenosynovitis around the wrist can be due to:
- lots of computer work - typing,
- using the mouse
- writing too much, or
- working on an assembly line for long periods
If you suffer from arthritis this can often affect your tendon sheaths as well as the joints.
Infection is a rare cause. But, if you have a puncture wound to the skin over the tendon, germs can get in and infect the tendon sheath. Or, infection can spread to the tendon sheath through the blood stream.