Its dangerous to do...Fighters have been known to use cortazone shots to get through pain but any fighter worth his salt would only allow it if need be....Larry Holmes had hand problems and used to get real bad pains but in a few fights he used the shots on a need be basis....

If you have no real need do not do it...By not feeling anything in your hand you one do not only know if you are injured but how badly?

Also you real;ly can not gauge how hard you are/are not hitting...

Anything that involves altering be it something this simple or not should be a no no