Head and neck injuries make up 10% of all chainsaw contact injuries, and if you're contacting your head or neck with a chainsaw, I guess we could suppose most of those are due to kickback. I do know leg injuries are 5x - 10x more common than head or neck injuries, depending whose statistics you use.
Here's some info from an NIH study:
Ok guys, I think I got about 90% of my PPE ordered. Just need some steel toe boots now. Welcome all recommendations. Thanks!