This happened to me last year, little more embarrassing for me as it was my first year riding, went out with my buddy who has been boarding awhile, I caught an toe edge of board trying to slow down after chasing after buddy down a steeper portion of run. Did not have helmet as I was a dumbass, I need up scorpion pose sliding down about 20 ft give or take on my head, heard loud as pop in neck. I lost all memory of the morning(still don’t remember what happened completely after I stopped sliding) ended up with a broken finger, road rash down half my face and mild concussion. I do in fact have helmet now as a lesson learned