The damage to the two outer knuckles of a fist when striking concrete/tiles or other hard surfaces with the intent of breaking them would be the same as the damage to the two outer knuckles of the fist after striking some parts of the human anatomy.If you dont believe that then perhaps read about or even ask some top cage fighters what they think.

I assume you're talking about the first two knuckles, the inner knuckles. The only part of the human anatomy (that you might actually punch) that would come close is the skull. I've never punched a skull and I don't plan on it; it's not a very smart place to punch. However, I would much rather hit a skull than a slab of concrete, because one of them is harder and has no give.

If a person puts their hand palm down on a table then its the two outer knuckles that are the weakest(3rd and 4th knuckles from the thumb)

Skull yes and the jaw,temples(normal target area in Martial Arts)forehead and the cheek bone. Breaking of hard objects(not re usuable objects) is mandotary in some styles of martial arts to get higher grades.

I'm talking about punching with the last 3 knuckles, not the last 2.

The jaw, temples, and cheek bones are not nearly as hard as concrete. I don't need to read anything or ask any "cage fighters" to know that. As for breaking hard objects being part of MA gradings, I'm not really concerned about that. I hope that everyone here cares more about how well they fight rather than what color belt they have.

Limiting a students technique to a certain "way" or making breaking a part of a grading system is just plain ridiculous. Its part of the problem with martial arts today, they are still stuck in the past!

We have something known as science, and believe it or not...if you take a scientific approach to the martial arts/strengthening you will find a better, more effecient way to train than the traditional way.

Don't do something because your instructor says so...
Do it because it works for you.

I have to say, I was going to avoid posting on this thread as i was sure my opinion would open a can of worms, but now that Cownose has taken the flak, I will bring up the rear
Personaly, I see absolutely no comlimenatry benefit to punching from knuckle press ups. Like Cownose I have always found that striking with the wrist in natural alignment results in me impacting with the outer most 3 knuckles, like cownose I find this effective, and has not left me with any knuckle injuries whan I have had to do it.
As Dragonfire has said, it is down to you to find your own best practice, through appraisal, trial and error and common sense.
As for knuckle pushups, I think we are all in agreement that neuromuscular coodination, timing and technique are what make up the bulk of a good punch, any strength that you can bring to the mix via conditioning will help, but as it is not an overriding factor, such subtleties as hand position become moot. As long as the chest, delts and triceps get the stimulus to imrove from any push up/pressing movement, they will bring this to the punching party.
Knuckle pushups are a good tool for MA instructors as A) they are easy to get large numbers (a class) to take part in and offer good basic conditioning, and B) because they create discomfort, particularly to beginners, they are a useful tool in building character, and guaging dedication/mindset of new students.

I agree with that breaking being in a grading doesn't make sense. My core art never has and never will have breaking apart of a test.

This thread is definitely interesting, because I never thought of using the last three knuckles. I have always trained to use the first two, and when looking at the fist and the alignment, sure enought it aligns the wrist. When using the firs two the wrists is bent a little bit...

Board breaking has been discussed before in the Martial Art Forum. In our grading board breaking is mandatory and when breaking boards with the fist, the index/middle finger knuckles are taught to be used and I would think through trial and error and scientifically backup from centuries with Karate and Kung Fu, etc. We could probably argue this to death no doubt so in the best interest of everybody we will agree to disagree.

Board breaking is nothing more then another tool … which some don't like to use … but it should not be dismissed either. One of the biggest reasons we do board breaking is to teach commitment. In order to break anything you have to believe and you have to commit. If you don't commit you will learn very quickly how much it hurts. Using bags, focus mitts, slammer shields, wave masters, etc. are also tools but you are less likely to hurt yourself and thus you do not have to commit as much in order to use these tools. I know without a doubt when I hit it will be hard and what I hit will break whether wood, plastic or somebody's face.

One of the biggest benefits I got from board breaking is learning a technique better. When elbow smashing I learned to use my whole body. When punching I learned which knuckles to use to prevent injury to my hand. When front kicking I learned to pull back my toes. When step side kicking I learned not to push but to chamber my leg and thrust through. When back kicking I learned to turn my head first so that I could see the target and to keep my leg in close and kick back like a mule. When speed chopping I learned to use my whole body plus where on my hand would incur the most damage to the object, and not to scoop up but go right through. For jump front kicking I learned how to gain the most height by using my whole body as well again pulling back my toes. For back roundhouse I learned not to swing the kick but to turn my head and kick straight back and then pull it through. For ax kick I learned to pivot my foot and chamber my knee prior to raising my leg and bringing down. With jump spin return kick … well this is a little more fancy but it definitely has taught me that I can switch feet quickly and back kick somebody with power.

Can these be learned without board breaking … of course, no question. I could do the techniques when taught to me and practiced but not until I actually did the board breaking was I able to refine the techniques even more. With board breaking you have to be precise, who have to believe and you have to commit. I think many would be surprised if they never board broke and were asked to do it that things are not as easy as they appear.

My two cents … not looking for people to tell me I'm wrong or that I'm practicing out of date practices. Each to their own training and whatever makes you stronger. Board breaking has made me stronger … there is no question … there is no doubt. I hit … it breaks … I believe because I committed.

Good post and I agree with you. It works for you, then use it. And i was gonna reply and say you could learn these things without breaking, but you covered it.

When I was younger and made the rank of 1st or 2nd brown belt, I wanted to try my skill at breaking. Like I said, in my dojo we don't practice breaks. Anyway, I had my father and wife, too funny, cuz my wife was behind him to brace for the impact. So, I got some BALLS and was going to try and break a 2x10. Not a standart board for breaking, but I was going to try it nonetheless. Welp, I commited, focused and broke right through, and almost punched my dad in the chest. No injury, didn't think my technique could have improved because my punch was like i was taught and I never bgroke a board in my life before that time. Not sure if my story has an real bearing, but i wanted to share it and whatever works for anyone, then use it.

Good stuff MrMoyer. The elbow smash the the punch are the first two board breaks we learn as they are some of the easier ones ... not to take away from anything you've done or anybody else. The most difficult that I have come across is the jump front kick as it has to be at least 1 fist high (to get height and toes back) and the back roundhouse (not to swing and be precise). The jump spin return kick on one of my sides is a little off but lots of power. Sorry Dave ... I think I broke his hand when I missed.