Repetitive Strain Injury, or Occupational Overuse Syndrome, is a general term that covers a variety of overuse injuries to muscles, tendons and nerves, predominantly of the forearm, wrists and fingers. RSI is an increasingly common condition that affects many people who, for instance, use machines that vibrate constantly, play a racket sport, use a keyboard or play a musical instrument. Such activities require repetitive movements of the fingers and wrists, often at speed, for hours on end.
Medical treatment for Repetitive Strain Injury includes rest, anti-inflammatory medication, pain killers, steroid injections and physiotherapy. The NHS Direct Website also states that learning the 'Alexander Technique... may help'