The Less The Force Exerted On The Body. Padding in the pole vault pit increases the time and distance through which force is absorbed. By using a roll or a series of rolls, one increases the time and distance over which momentum is lost. Giving with the impact will incease the time and distance over which momentum is transferred to the body. In catching the perforer gives by pulling the arms back toward the body at the moment of impact and if necessary, takes a step back or rotates.
Bones discontinue to grow - cartlagenous to ossification completed at full maturity.