Pooor Sca has been a crash and burn expert.
Last night we are playing frisbee and stop for a rest. He become a lap dog for some petting while he rests

Well after about 30 seconds he decides "enough of this time for frisbee" and goes to jump down. Well he misses and kind of falls off my lap with his back leg dropping between the slats on the lawn chair

out comes an incredible screech. Well I quickly grabbed his butt and lifted (for once a big sheltie butt is good). He scoots off limping a bit and would not let me check his foot for about 2 minutes. Well other than a bit of a cramp he was fine. A couple minutes more and he is tossing the frisbee down and barking.
Then this morning I decided he needed a bit more play time before I head to work so we go to play frisbee. Usually when I wind up he turns and goes out. Frequently he goes right by the trailer tongue and a couple of times I thought he was going to hit it but he always misses. Well you guessed it this morning WAMMMM right into it and a yelp. He gets up from the crashes and goes behind me to hide from the trailer. Well I check him and give him some sympathy pets but he is OK. Back to frisbee and the next throw he looks for the trailer instead of at the frisbee on the way out

. Of course he does not catch it but the time after he was back to normal but had altered his line to give the trailer a foot or two extra.
Oh and the video is not that great but I might have a short bobbing for ice clip tonight.
EDIT: and the battle is on. He has decided that he needs to go on the roof of his carrier and across the bed is the best route. So he got put down last night..... 4 times. That thread about self punishing, nope he has zero shame or guilt just a smile like "hi dad"