I'm frequently amazed at the amount of damage that can happen to the human body without realising how damaged it is.We were doing stand-up gi grappling, I had a grip on my partners sleeve and he used the grip break where you bring your knee up and over and down to break the grip. He just did it more ballistically than necessary and managed to contact my thumb rather than my wrist. It was moderately painful, but I’ve felt much worse. (And in a real fight, adrenaline would have blocked most of the pain until later.) I’m pretty sure it eliminated my ability to grip effectively with that thumb. I wasn’t 100% sure it was actually broken until I got to the ER and saw the x-rays.