RSI stands for Rod Stroking Injury. It is most commonly found in fluffers, anglers and firemen. The emergence of this affliction in the 1990s is commonly believed to have sunk Bill Clinton's plans for universal health care. Since Republicans held that firemen are invariously gay, that angling is excruciatingly gay, and that fluffers had an alternative to using their hands (and were anyway soon to be replaced by tadpoles), they voted down all 486 of Bill's bills.
Gulf War veterans, backed by a number of medical researchers, claim that RSI is especially prevalent among soldiers, but the Pentagon and other military mafia have denied that the condition exists. Instead they prefer to talk about GWS, or Garrotted Wiener Syndrome.
Some practitioners of alternative medicine have claimed that the wearing of supportive colors is effective in treating RSI. Green and ocean blue have been found to be particularly supportive colors.
In extreme cases of emergency the other hand may be used.