Years ago, in high school, a female coach forced me into a split although I had never done one before ,had no warm up or previous practice. I kept saying I couldn't do it and she said I would fail the course and get detention if I didn't do it. When I attempted it -under duress- my knee promptly popped out of its socket! You could see the ball and socket as I screamed in agony and fell. I was taken to the school doctor who was outraged and said this should NEVER have happened and that I was lucky it had popped back into place, as I fell on it, or I might have needed surgery! Meanwhile, the evil witch of a coach stood there and said "Anne if you couldn't do it -you shouldn't have tried!". Oh -and the end of the story? That knee has ALWAYS bothered me and arthritis set in and eventually I needed knee replacement surgery .All thanks to this" trained" coach. Children who are shy, like I was, HAVE to be taught by their parents, to say NO- to some things -even if it's an adult ordering you!