Soft spot in the shin

[Garland]

I noticed a while ago while I was tapping my leg against a desk...kind of a nervous thing I do...that there is a certain spot about half of the way through my shin that seems to be weaker and more sensitive then the rest of the bone.

This area also seems to be where I see most of the leg breaks occur. Maybe this area isn't as dense and as the kick goes in, it acts, because of it's location on a fulcrum, and the shielding leg as a wedge that makes it easier to break. I don't know very much physics, not the kinesiology behind it...but look at these, and notice where the break occurs...it looks like the same spot everytime...why is that? Just some food for thought. (warning, this is some graphic stuff.)

http://www.youtube.com/watch?v=Yee_wVjgDbc&search=leg%20break

http://www.youtube.com/watch?v=2VR-b3cEx0M&search=leg%20break

[eXcessiveForce]

Yup that's the weakest point of the shin.

If you take a uniformly constructed rod, and appy pressure it will break in the middle,

The leg is not uniform, but that is the place of maximum pressure when the shin is struck,

[seppuku]

Im not quite in complete agreement with eXcessive Force. Consider a long plank over a river. Walk over it. Bends most when your in the middle, so this part is under the greatest strain. This is also where the plank will break if you're unlucky. With the leg break however, both ends are not fixed in place.

When the leg is effectively fixed in only one place i.e. at the hip, a force applied at any point will cause the most strain on the part next to the hip. The leg would break here if it was uniform and going to break anywhere. The leg is broken while kicking, so the other end is not fixed in place, so shouldnt act like a plank across a river.
The leg is not uniform however. The end nearer the hip is thicker as far as i know so this part takes more strain before it reaches its breaking stress. If the bone generally tapers, with the top thicker than the bottom, i image the leg breaking in this place is the resultant of strain increasing nearer the hip whilst bone strength also increases. This is basic materials science, but as thats all I know at the moment its the best i can apply.

The above is a longwinded way of saying that this spot isnt actually the weakest point, this would be nearest the ankle, but that its likely to break here anyway. I think eXcessive put it better somehow. This is what happens when I post at half 1. Sorry