Use less force and not jump as high. He was going up to block the shot, chasing from behind. And no, you have your physics wrong; the primary force is used to ELEVATE, not descend. The force is applied against the floor as you jump. You do NOT come down with the same force as when you jump. You don't jump DOWN. There is no extra force exerted in the air. Coming down is all about gravity. If you jump 30 inches, you come down with more impact than if you jump 6 inches. If you weigh 300 lbs and jump 30 inches, you'll hit the ground harder than if you weigh 100 lbs and jump 30 inches. The impact was primarily caused by him running, because his path was towards the stanchion. So after he jumped and reached maximum height, his trajectory carried him into the stanchion, where his foot landed sideways against the pole. Had it been a slightly different angle, maybe his ankle would have broken, or ligaments would have been torn. Without the stanchion there, I doubt any injury would have occurred. Well, can't say that for sure, maybe jumping sideways and landing on one foot would have sprained an ankle.