XP

If we took the strength of a human femur that can withstand a bite force of 1700 psi (Sounds per square inch) as a base line, we can gain a better understanding of the bite forces of animals. Coincidentally, you'll also realize how insanely hard a femur is.

To snap a femur, you would need a bite force of 1700 psi. Tigers only have a bite force of around 1050 psi. Surprisingly, lions only have a bite force of 650 psi. Most people also seem to be under the impression that lions are larger than tigers.

The big cat that's able to crush human bones happens to be the jaguar with it's bite strength of 2000 psi.

[Dont mess with jaguars, they'll chomp right through you.]

So you might be thinking that it should be impossible to break your femur with just a fall. This is something that not even a lion can bite through. That's where the perfect force comes into play. Another way to put it is; if you're unlucky you can always break a bone.