折断一根人骨到底需要多大力量？

小白老师说：据说世界上出拳最重的人是泰森，他一拳能打出 800 公斤的力量，曾一拳打断波兰拳王安德鲁的颈骨，简直就是雷神本人啊！心有戚戚之余，小白老师不禁想问，作为可怜的普通人，人骨到底有多硬？折断一根人骨到底需要多大力？相信读完本文就有答案了。

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How much force does it take to break a bone?

What does it take to break a bone? Could I do it with my bare hands（赤手空拳）?!

Recently it came out that during the filming of the latest Star Wars movie, a hydraulic（液压的） door broke Harrison Ford’s leg. This got us wondering: how much force does it take to break a bone?

As it turns out that question is a lot more complicated than it sounds. Adults have 206 bones that come in a lot of shapes and sizes, so some bones are going to be a lot easier to break than others.

The largest bone in your body, your femur（股骨） or thigh bone（股骨）, is a lot harder to break than the long slender clavicle（锁骨）, or collarbone（锁骨）, which one of the more commonly broken bones.

Part of this has to do with the of muscle around a bone that supports the bone and absorbs some of the impact from a hit. Your femur encased in all your leg meat, and that can take more of a hit than your rib（肋骨）.

Dr Cindy Bir of the University of Southern California estimates that a force of 3,300 newtons has a 1 in 4 chance of cracking the average person’s rib, while their femur typically takes more force to break: around 4,000 newtons.

There isn’t a set number for what force will break a bone like a rib because how the force is applied makes a difference. A blow perpendicular（垂直的） to the bone is going to do more damage than when that same force is applied almost parallel（平行的）, and that’s because of how bones are built.

Your bones are actually made up of two types of bone tissue: cancellous bone（松质骨） and cortical bone（密质骨）.

Cancellous bone is the spongy（海绵样的） inner material and usually contains red bone marrow（骨髓） that makes red blood cells.

Cortical bone, also called compact bone, makes up the outside. It’s dense, hard, stiff, and accounts for 80% of your skeleton’s mass. This outer layer is made up of columns of of collagen（骨胶原） and calcium phosphate（磷酸钙）, like bundles of twigs（末梢）.

Collagen provides the soft framework in the bones and calcium phosphate adds the strength. Because these columns run vertically（垂直地）, they give your bones strength down their length.

Bones are great at taking compressing forces like when you jump but can’t deal too well with shear forces like when someone hits you with a car. Certain people might also just have stronger bones, depending on their diet, age, and lifestyle.

Your bones are dynamic（动态的）: they’re constantly being broken down in a process called resorption（再吸收）, and rebuilt. Because a big component of them is calcium, a diet low in calcium means your bones will probably be a bit more brittle（脆的）.

And just like with muscle, putting stress on your bones through exercise can make them stronger. That’s why astronauts（宇航员） come back from space with reduced bone density: floating around up there means their bones aren’t getting the same stress they would on earth. But even if your diet and exercise routines are great, there’s no fighting age.

Our bones reach a peak density around age 30 and then begin to decline when the resorption of bone happens faster than formation. Eventually this can lead to osteoporosis（骨质疏松症）, a condition where bones are weaker and can fracture（骨折） more easily, sometimes even under normal use.

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