To Rambo Balboa,
All the information you received is solid knowledge, here is my routine I use for my knuckles and hands, my art is KAJUKENBO. First let me say when striking or punching always make sure you are contacting your index and middle finger knuckles, they have the larger bone support not having your wrist in proper alignment could cause you to strike with the smaller knuckles on your hand, result broken bones in your hand. (FIST closed) My routine; 1. I rest my two big knuckles on a board, I have a small bench maybe 8" off of the floor made from 2x8s, I stay in this position 1-2 minutes (as a beginner less time is ok) it is the same position as a knuckle push-up, I don't do knuckle push-ups because at certain motions of the push-up your allowing the weight of your body to release pressure on the knuckles. 2. I go to a full horse stance and hit a sand filled bag 250 times each hand, using a reverse punch configuration, then same amount of times in the hammer punch configuration. 3. Then I move to a stone bag and do the same amount of strikes in the same configuration. 4. I then use a concrete slab and repeat what I have done on the wood. 30 sec-1 minute break, drink water and repeat. I do this for 4 sets. When I'm finished I then tune the knuckles on a round steel pipe for 1 set, not hitting hard just steady.. The back of the hands and the palm of the hands are trained the same way, except I slap the wood and the concrete. IMPORTANT: Nothing is achieved over-night I have been training my knuckles & hands for several years, two important facts, it isn't hard as you can hit, it's steady pressure and concentrating on the strike of the knuckles make sure you are exercising the appropriate knuckles and not the small knuckles. This routine will hurt but with work and dedication you will have Mickey Mouse knuckles, that is what my students call my knuckles. Remember breaking bones don't make the bone(s) stronger, so be careful and train well.
DRAGOON