Monday, June 27, 2022

Human Rib: Fragile?


There I was, in public without a responsible adult and I was wondering what mayhem I could commit with my inexpensive walking cane should need arise.

Given the fact that it was manufactured from 1.0mm wall aluminum (probably 7075-T6), it didn't weigh much more than a fart on an elevator. Using it as a bludgeon was a non-starter. That left using it as a poking-tool as the only viable option.

According to the manufacturer, the cane was rated for 300 pounds at full extension. Since buckling load is proportional to 1/length^3, shortening the cane would vastly increase its load capacity and make it more robust for side-load. Shortening the cane also makes it easier to control and lowers the possibility of a thug taking it from you.

The preferred grip is to hold the handle beneath your boob and tightly clamped to your rib-cage and have your supporting (aiming) hand palm-up and gripping the ferrule. Maximum force comes from stiffening all of your joints and rotating, similar to clearing away defenders with your elbows after rebounding a basketball.

How much force to break a rib?

Given the elevation of the cane, the assailant's rib-cage is the only viable target.

The question of the day is "How much force does it take to break a human rib?"

Location of samples.
There are very few academic papers that are not behind paywalls. This one is not behind a paywall and looks at young women ages 10-22.

Cross-section through human rib (female). Approximately 11mm along long axis and 4mm the narrow axis. Wall thickness varies between 0.8mm and 0.3mm.

The STRONGEST sample they tested of 33 samples taken from 17 women broke at 5.5 N-m.

That would be analogous to a six-inch sample supported on both ends by resting on a table and only being able to support 32 pounds applied to the center of the sample.

In my mind, that translates into about 45 pounds for a young male. Or, stated another way, poking a young thug in the ribs with the tip of my cane with a delivery force of 50 pounds is likely-to-highly likely to break one of his ribs.

What is the gut feel among you readers? Too high? Too low? Seems reasonable?

I was dismissive until I read that if you are not breaking ribs on patients while applying CPR you are probably not doing it right.

Ribs seem rugged because they are flexible and because they exist in a mesh of muscle that allow them to seamlessly shift load to neighboring ribs. In fact, we rarely talk about a "rib" singular because they work as a system. It looks like it takes surprisingly little load to break a rib (singular) when applied as a point load.


  1. Ok, but follow up to throat or nose.
    Usually run in packs, Mr Glock is a handicapped person's friend.

  2. When I was a member of my Department's riot squad (we had many names over the years but that is what we were). We were issued riot batons which had a half inch pointed nipple on the business end. These were known as rib spreaders. They resulted in quick pain compliance for anyone not wearing armor without having to resort to an overt swing.

  3. In my professional experience, younger people with very flexible ribs do not readily sustain fractured ribs even during prolonged and vigorous CPR. Contrariwise, older people with more calcified ribs do.

    Again in my professional experience, rib fractures really do require short sharp shocks of the non-electrical variety, rather than swinging blows. As a generalisation. For example, full-on tackles on the sports field do not commonly result in rib fractures, but putting the boot in when an opponent is down, does.

    Some years ago, when arthritis forced me to engage with a cane, and living in a country where it is not possible to legally use a handgun in self defence - I purchased a cane from here - - and brought it home. Along with some training material off Amazon.

    Disclaimer: just a satisfied customer. Neither connection with this company.

    1. Joe writes: Thanks for the link

  4. I concur with other soft targets, or a sharper point. Ribs are armor. Why strike at an enemys armor hoping to break or penetrate it, when un-armored targets exist? Successful anti-tank systems attack from the top, not the sides, due to less armor plating there.

    1. Joe writes: Regarding ribs being armor, biologically they exist primarily to provide a rigid "can" so downward movement of the diaphragm results in air entering the lungs.

      The unarmored targets are higher (or lower) on the target's body and strikes will be delivered with less force and the cane might be more vulnerable to being wrestled away from the user, leaving him tottery and unarmed.

      My thinking on this is evolving so these are my first impressions.

  5. Collar bone. Way back when, the guy who trained me in the use of a PR-24 said the collar bone was an ideal target. It only takes about 8 pounds of force to break.

    1. Under the collar bone is a channel that has a major artery and vein, and nerve bundle for the arm. I always looked at the collar bone as a lethal strike because of the plumbing that runs through there.

    2. That's a feature, not a bug.

  6. We have a senior instructor at our dojo that also teaches the Cane Masters system and every so often the rest of the students get a taste. Pretty effective stuff, especially when you start using the crook as a choke point or for a hooking strike.

    As far as carry issues, one student who is a TSA agent confirms they will NOT take a medical assistive device (aka your cane) from you during travel. Takes away the issue of keeping a softball bat in the car.

  7. If things are going so well that you need to stop the action, ribs aren't going to be my choice. Looking to end the game, not extra innings.

  8. Rattan cane as used in escrima/arnis is both light and moderately flexible. The strike damage it does is more speed/hardness related than weight (with an emphasis on leverage and locks). Striking targets are primarily head, hands and joints (collar-bone(strike), muscle mass, and solar-plexus(thrust) are also but ribs … not so much, you need a much heavier weapon usually).

    My primary targets are the hands as I know a sharp hit to the knuckles ‘can’ render a person not just hors de combat, but unconscious (don’t ask how, I seem to be my instructors favourite guinea pig – ouch!).

    Historically, Savate and Le Canne (walking stick defence) seemed similar (joints, hands, head) with a much greater emphasis on thrusts to the body/head (similar to fencing) but Pierre Vigny's requirement for the inclusion of a heavier metal knob allows for more ‘knock-outs’ and perhaps rib damage(?).

    So … add a knob and who knows.

  9. I use one. Nicely weighted for use in a swinging attack.