How much force does it take to snap the femur?

We put this to Dr Ken Poole...

Ken - Normally, it's thought of in terms of the amount of energy available in a fall; and it's a surprisingly little amount of the energy: about a fifth to a tenth of the amount of energy in a fall is enough to break that femur.

With a hip fracture, there's such a thing as the perfect force. If you are unlucky and fall backwards and to the side - even if you're young - you can snap your femur.