I was riding my pint for around the 30th time when it suddenly did a sudden stop and nosedive throwing me off. I was under the speed for it to start engaging the pushback. Just a cruising speed around 12 or 13 mph. I was on flat pavement and had plenty of battery power and wasn't riding aggressively. Just a nice cruise. I did some practice falls on grass but I had never truly fallen, and felt comfortable on it. I was loving it in fact. But when it did that sudden nosedive, it's incredibly difficult to fall gracefully or run out of it. I shattered my left elbow quite badly. I had to have 3 surgeries on it totaling well over $100,000. I broke the radius and ulna near the elbow. I had to have part of my radius sawed off and a prosthetic radial head installed. I also had to have a massive plate put on my ulna that makes my arm look disfigured. My arm will never be anywhere close to 100% and I lost a lot of my range of motion. I've been off work for 4 months now in recovery.