I like the last posting, but I think I'd reiterate the unquestionably wise move of talking to a doctor about this practice.
Like I typed in a previous post, your instructor might be primarily interested in making you into a better fighter in the near term. Your long-term ability to type, write, etc might not be at the front of his mind. Even if it's something he thought about, he's probably not a doctor. Even if he's older and has no problems, that doesn't tell you much either because people have different levels of vulnerability to health problems, with genetics playing a part.
If you're like the vast majority of us, martial arts is just a temporary hobby (don't kill the messenger -- that's my observation). It's stupid to sacrifice many years (hopefully you'll live that long) of functionality to gain something in a temporary hobby.
Martial arts are great. There's just no reason to be unwise. Get with your doctor before doing much of this.