Question about shock resistance on falls?

Question

how do you reduce the amount of shock to your legs on a big jump? (20ft)

I'm not talking about if a building collapses or anything but those people who do those big jumping stunts from bridges and small buildings.

Answer 1

From a physics point of view this has to do with impulse.

Basically impulse if the change in momentum divided by the time over which it happens.

So if a person jumps from a building and lands with their legs slightly bent, then can absorb more impact. As they land their legs bend which increases the time over which they land and thus they are better able to absorb the energy without damage.

If they jumped and landed with their legs locked straight, then the force would travel up the legs almost instantaneously and thus they would be damaged.