I don't know about that leg bag. I played ball for a few years, been watching for many more. I've seen some guys take some wicked shots to just about every part of the body.
Say you get hit, and maybe the sight of your beer spilling causes you to faint. Then, much like I imagine most parties you attend, you awake, soaked in urine, not sure if it is your own, but this time, there are 50,000 people watching, as opposed to the usual 8-10.
I would imagine that waking to such a scenario might be most injurious to one's mental health.