Several Conditions are referred to as repetitive strain injury. These are conditions caused by the constant repetition of a particular movement. Irritation of the flexor and extensor tendons in the wrist and hand is a common injury that often affects keyboard operators causing pain when the fingers are moved.
It is also a condition suffered by body builders and weight trainers who constantly put strain on the same muscles.
The symptoms of RSI include pain, aching and tingling. Sometimes restricted movement or weakness.
RSI can also lead to another disorder called carpal tunnel syndrome. This is due to pressure on the median nerve as it passes through a gap under a ligament at the front of the wrist. This disorder is characterized by numbness and pain in the thumb and middle fingers. The condition is caused by pressure on the median nerve.
For more information on muscles Click repetitive strain injury