I think that voice recognition can help reduce the number of keystrokes required for programming. I am using Dragon NaturallySpeaking to write PHP code, and I have created a number of commands to output frequently used statements. As mentioned by others, navigation within the code is a difficulty.
I would advise anyone with repetitive strain injury to try to minimise their programming in as many ways as possible. For example, think about what you want to do carefully before you sit down at your monitor. Use a pen and pencil to write pseudocode. Make your code as reusable as possible. Stick to best programming practices. Get away from your screen; read books. Vary your work position; I lie on the floor with my iPad. Try android voice recognition for answering short emails or text messages; it's free and multilingual, and pretty accurate in a quiet environment. Stand up and walk around. Think about getting someone else to do your programming for you.
