Josh Kaepernick is just lucky he hasn't been severely injured by now, considering he's been pulling that with his legs running over linebackers for 6 years and counting now.
Some LB or safety on KC needs to aim straight for the knees, on purpose, like what the Browns DB did to Gronkowski in 2013, with their helmet when he's running north south full sprint. It's a legal defensive play when it's vs a runner and not a thrower in the pocket. Obviously you can't go anywhere near the head area or you're looking at ejection and massive fines and suspensions.