For me it was when I bruised my spine and then pulled a muscle in my back in the same hour. This happened in an open gym my freshman year of highschool. I was lowk cooking against the upper classmen and had 14 points which was decent. But then I tried to rebound over a junior who was I think around 6'5 or he might be taller. And I kinda got pushed a lil and landed on my back and that really hurt my ability to get into defensive position and stuff but I pulled through. But then after a few possessions I tried to rebound over him again and I actually jumped pretty high but I landed and felt something wrong again so the athletic trainer person checked my back and said I had pulled something. She also said after what I told her I had probably bruised my spine. Idk that sucked but wasn't too bad I was good after a few weeks.