The Basics of Board Breaking

Last week I  talked about why some schools break a lot of boards, why some schools don’t break boards at all, and why we’re somewhere in between. This week I’d like to talk a bit about breaking itself. There are a lot of myths out there about breaking. Many of them are perpetuated by martial artists – sometimes nefariously, but most of the time out of ignorance.

While you can theoretically pick up anything you’d like for a breaking demonstration (it doesn’t even have to be wood!) most schools use small variations on the same basic concept. Schools that do serious breaking mostly use some variation of a 12 inch by 12 inch white pine board, around one inch thick. That’s an approximation because most martial artists will just go to the hardware store and by standard lumber (it’s what I do). Standard lumber doesn’t come in perfect one inch increments because it shrinks after it’s cut.

What I usually do is buy a long 12×1 board, in whatever length is most economical on the day I’m at the store. Then I’ll get them to cut it into 12 inch sections. However, a 12×1 board is usually actually 11.75 inches by 0.75 inches, or very close to that. Also, having it cut into 12 inch lengths usually means that the last one is closer to 11 inches.

I buy white pine. As I mentioned last week, some schools use even softer wood such as balsa (thankfully this isn’t very common these days, as it’s too easy to have it embarrassingly pointed out during a demo). Don’t buy hardwood like oak, cherry or ash. It’ll break your hands. Just as importantly, do not buy pressure treated lumber (more on that in a minute).

A standard 12 by 12 white pine board takes about 1100 newtons (roughly 250lbs) of force to break. Because wood is a natural material, that varies a bit from board to board. A rule of thumb generally taught to martial artists is that breaking one board is equivalent to break one rib. This is, sadly, one of those incorrect myths taught to most martial artists by their instructors and never questioned. Safety studies done by the Society of Automotive Engineers show that it takes about 400lbs of force to break a rib. That varies a bit depending upon which rib (the smaller ones at the bottom of the rib cage break easier than the thicker ones at the top of the rib cage). 250lbs might crack one, but it’s unlikely to break one.

250lbs isn’t that bad. The average adult male in the US ways just shy of 200lbs. It doesn’t take super great technique to come up with another 50lbs of force – but it does take good technique to properly protect your hands, feet, or whatever else you might be hitting with. That’s why I don’t have brand new students doing board breaks, whatever marketing advantages might come from it. I don’t allow students to do breaks until I’m comfortable that their form is sufficient to prevent injuries.

For simple breaks the board is placed or held between two supports. The first break I have most students do is with a downward hammer blow, so the board is usually placed on two cinder blocks. The blocks are situated in such a way as to hold the board steady but with the maximum distance between the two blocks. For breaks that use techniques such as a punch or a kick the board is usually held by one or two people, but in a similar manner. The arms are posted strong on either side of the board, with the minimal amount of hand coverage necessary for grip. Either way, this represents the “width” of the board.

The wider the board is the easier it is to break. If you’ve ever snapped a stick over your knee in the woods then you’ve likely discovered this for yourself. Going wider than 12″ results in boards that are ridiculously easy to break. Going less than 12″ wide can result in boards that are very difficult to break.

The last dimension is the height of the board. For adults, I use standard 12″ height boards. For children we go smaller – 10″ or 8″. Some schools go as low as 6″ or even 4″ boards. My personal opinion is that if the child is young enough to need a board that small he probably shouldn’t be breaking anyway because his bones are still in development. Even with the older children, I do less breaking than I do with adults – and I don’t do all that much with adults.

One final trick that some schools play is to bake their boards or bricks before they break them. Yes, bake in the oven like a cake. Baking the wood or brick removes moisture which makes it much easier to break. This trick is done with bricks far more often than with wood. From a distance you can’t tell that the brick has been baked – unless you see a giant puff of powder when it’s broken.

On the flip side, never break a board or a brick that is wet! That reinforces the material and will very likely break your hand or foot – especially if it’s a brick! Get breaking materials that have been kept dry and be sure to keep them dry before your breaking session! For the same reason, avoid pressure treated lumber and get only the untreated variety. The chemicals they treat it with will retain a lot of fluids (not water but chemicals) in the wood and make it much harder to break. I once witnessed a belt test where the student had been assigned to purchase his own boards and he absolutely could not break the board. The instructor later pointed out that it was pressure treated, and that was why.

Above all, if you’re going to do any breaking have somebody around who knows what they’re doing – and even then, be careful. It can be fun. It can bee a good way to prove to yourself, and others, that you’re capable of generating a lot of power in your blows. But if you’re not careful it can be a short road to a serious injury.