The most common types of repetitive motion injuries are tendinitis and bursitis. These two disorders are difficult to differentiate and many times may coexist.
- A tendon is a white fibrous tissue that connects muscle to bone and allows for movement at all joints throughout the human body. Because tendons must be able to bear all of the weight of the attached muscle, they are very strong.
- Tendinitis is an inflammation of the tendon. (Whenever you see “-itis” at the end of a word, think “inflammation.”)
- Common sites of tendinitis include the shoulder, the biceps, and the elbow (such as in tennis elbow).
- Males are slightly more likely to have this disorder.
- The inflammation of the tendon usually occurs at the site of insertion into bone.
- Tendons run through a lubricating sheath where they connect into muscle, and this sheath also may become inflamed. This condition is known as tenosynovitis.
- Tenosynovitis is almost identical to tendinitis because both have identical causes, symptoms, and treatment.
- Tenosynovitis of the wrist may be involved in carpal tunnel syndrome, the most common compression nerve disorder, but this cause-and-effect relationship has never been proven.
- A bursa is a small pouch or sac that is found over an area where friction may develop and serves to cushion or lubricate the area between tendon and bone.
- Bursitis is inflammation of a bursa sac.
- Over 150 bursae are in the body.
- Most bursae are present at birth, but some come into existence in sites of repetitive pressure.
- Common areas where bursitis can occur include the elbow, knee, and hip.
- Different types of bursitis include traumatic, infectious, and gouty.
- Traumatic bursitis is the type involved with repetitive motion injuries.
- Traumatic bursitis is most common in people younger than 35 years.