Repeat after me--always, always check that some idiot has not left the treadmill running.
I hopped on, and my feet were promptly carried backward. The rest of me, illustrating some lovely rule of physics I'm sure, pitched forward and then down. The brain on board was trying to make sense of this. Why am I falling? Oh, the treadmill is running. Who would get off a treadmill and leave it running? This can't be good. Oh, damn, this is going to hurt.
Then bang, whizz, I'm on the floor.
No personal training for me. Instead I go off to my regular doc and then on to the plastic surgeon for two stitches to go with my assortment of scrapes and bruises.