Been there, done that.
The seemingly endless cycle of edit-test-edit-test takes its toll on programmers, especially video game programmers, who must not only use their hands when writing code, but when play-testing their games.
From Siliconera, Super Smash Bros. Creator Suffering From Repetitive Strain Injury:
Masahiro Sakurai, who is currently hard at work on two Super Smash Bros. games for the Nintendo 3DS and Wii U in collaboration with Namco Bandai, says that the strain is reaching “the point where it’s starting to restrict my work and lifestyle”.
Using a mouse, keyboard or gamepad add to the strain, so Sakurai’s solution is to use a trackball instead of a mouse. In addition, he plans to start giving more verbal directions during development, as opposed to writing e-mails, and cut down on the amount of typing he has to do himself.
Those tactics may help, but really, it will likely take an extended rest to recover full use of his hands. And that break is hard to take when the pressure of a deadline is breathing hot and heavy on your neck.
Good luck, Masahiro!