First of all, you most certainly are grappling with people quite often in karate--what else do you think you are pulling your hand back to your hip for, and what exactly do you think your other hand is doing when one of them is striking or blocking with your knife hand, for example? In addition, strong muscles, ligaments and tendons in the hands will help prevent injuries while striking because those are the things holding your bones in place when you punch. I must of overlooked all that hah thanks for the help!