Repetitive Strain Injury

Repetitive strain injury, also called repetitive stress injury, is a loose group of conditions from overuse. It is an occupational overuse syndrome affecting muscles, tendons and nerves in the arms and upper back. The medically accepted reason it occurs is when muscles in these areas are kept tense for very long periods of time, due to poor posture and/or repetitive motions.

It is most common among assembly line and computer workers. Good posture and ergonomic working conditions can help prevent or halt the progress of the disorder; stretches, strengthening exercises, massages and biofeedback training to reduce neck and shoulder muscle tension can help heal existing disorders.

Specific conditions
Repetitive strain injury is not a specific disease but a loose group of other, more specific conditions. Many of these disorders are interrelated, so a typical sufferer may have many of these at once. In this case it is often best to treat RSI as a single general disorder, targeting all major areas of the arms and upper back in the course of treatment.

The most famous repetitive strain injury is carpal tunnel syndrome, which is common among assembly line workers but relatively rare among computer users: computer-related arm pain is generally caused by another specific condition.

Some of these are:

Carpal tunnel syndrome
DeQuervain's syndrome
Intersection syndrome
Reflex sympathetic dystrophy syndrome (RSDS)
Stenosing tenosynovitis
Tendonitis
Tenosynovitis
Thoracic outlet syndrome
Trigger finger/thumb
Ulnar nerve entrapment

Warning signs
RSI conditions have many varied symptoms. The following may indicate the onset of an RSI:

Recurring pain or soreness in neck, shoulders, upper back, wrists or hands.
Tingling, numbness, coldness or loss of sensation.
Loss of grip strength, lack of endurance, weakness, fatigue.
Muscles in the arms and shoulders feel hard and wiry when palpated.
Pain or numbness while lying in bed. Often early stage RSI sufferers mistakenly think they are lying on their arms in an awkward position cutting off circulation.

Symptoms may be caused by apparently unrelated areas, for example hand numbness may be caused by a nerve being pinched near the shoulder. In the initial stages of RSI, an area may be in quite bad condition but not feel painful unless it is massaged, or feel weak unless a long endurance exercise is performed. Therefore all areas of the upper body are considered when evaluating an RSI condition.