if u jump onto the floor, are you more likely to be hurt if your legs are relaxed or if your legs are stiff and your knees are locked? explain....plz help =)

If your knees are flexed rather than locked, they can apply an upward force to the rest of the body for a longer time during the deceleration. Since force x time = momentum change, and the momentum change is fixed, more time (flexed knees) results in a lower force on the knees.