Happened to me on a custom motorized bike. After three years of basically trouble free riding everyday, the clamp that holds the brake arm broke, brake plate spun, yanked the cable, and threw me over the bars at 45mph.
Landed shoulder first, with the elbow on my other arm jabbed into my chest.
Seperated left shoulder, my right elbow jab broke four ribs, right wrist, two fingers, and bruised my heart, lung and kidneys.
Two days in the hospital, two months of therapy, shoulder wasn't getting better, had reconstructive surgery.
Ended my 18 year tower climbing career, and took about four years till it didn't bother me anymore.
I used to be able to do 50 pull ups and endless push ups (from tower climbing arm strength.) Now I can do two or three. Maybe ten push ups.
Still feel it when it rains.