My CP has been in Allstar cheer for 10 years. She has, thank the good lord, only had minor injuries i.e. sprained ankles, broken nose, snapped tendon in her hand - all have come from stunting in Level 4 and 5. However, she did have a tumbling coach when she was learning her full that was a mental case and told her he had invented a telepathic spotting arm that was powered by his positive energy and that he no longer had to be on the floor with her to spot her. So I took her out of that tumbling private and took her to $100/hr privates at a gymnastics facility where she got her full properly after relearning layouts. Unfortunately she was mid season in the same Allstar program and that same instructor, the last practice before the first comp that she was gonna throw her full in routine that same coach told her he had had a nightmare about her busting her full on her head in competition and splitting her head open... took 2 years and some great coaches at her current gym to get her over being mentally afraid of her full!! SO IMHO COACH TRAINING IS A DEFINITE PRIORITY!!! Not just technique but psychology too!!
Sidenote: That coach now owns a power tumbling gym:help: