I started with a suspicion that training some martial arts is more dangerous than the risk of being assaulted. I didnt' know, and I still dont' know.

@FussyBoots If you like you can call this my hypothesis and test it statistically. However really this isn't the question we should be asking. The hypothesis that people here are assuming is that martial arts reduce the risk of injury overall. THIS should be the Alternative hypothesis to the Null hypothesis of martial arts having no risk benefit or negative risk.

I am a martial artist the same as just about everyone else on this site. I would like there to be a statistically significant benefit to martial arts... I just suspect there isn't.

As for your side note. I would say that is a valid question that should be considered by law makers. The outcome is unclear as yet to that too.

I'll agree that the issue of injuries is an important one to consider. I considered writing my own question on injuries a few days ago, namely that I had been told a few years ago that the majority of injuries are single-person injuries, strains and the like, and most of those from people returning to the martial arts after an absence.

The theory being that the human body starts with the capability to move very quickly and powerfully from the start and what we really train in martial arts is how to stop yourself before injury. So when you go back to it, you still kick head-level, but can't halt the motion before you strain tendons. You punch faster than you can stop it, hyperextending the elbow. Etcetera.