Had to keep hitting stop,can't tell where his knee hits
got this off of an Officials Forum
The relevant rule is 2-40-3:
"The dead-ball spot is the spot under the foremost point of the ball when it becomes dead by rule."
In this case of the runner's knee hitting the ground, the ball becomes dead when his knee hits the ground. The dead-ball spot then is the foremost point of the ball at the moment his knee touched the ground.
but i still can't tell where his knee hits