At my job, I'm on the computer a lot, and it is a very mouse-heavy type of usage and not much opportunity for keyboard usage.
For the third time in my career (I'm 39), I have injured my arm, hand, and wrist from excessive mouse usage.
Our on-site occupational nurse and doctor reminded me that this qualifies as a workplace injury and all treatment for it is covered as such, including worker's comp if it comes to it.