Wax On, Wax Off...and Sorry About Your Nose.

Nice example case for discussions of assumption of risk (and consent, though it's not mentioned)

A woman whose nose was broken during a sparring match at a Long Island, N.Y., karate school was an experienced practitioner of the sport and had assumed the inherent risk of injury or "even death," a state judge has concluded in dismissing her lawsuit against the school and its owner.

* * *

"Therefore, the court finds that being struck in the face while sparring, which itself involves punching and kicking your opponent while attempting to block punches and kicks from your opponent, was a risk that was known and apparent to this plaintiff when she chose to take this sparring class," Doyle wrote. "Indeed plaintiff signed a contract with the school which states, in part, that plaintiff acknowledges that the risk of sustaining an injury resulting from broken bones or even death is inherent in the sport of karate and plaintiff waives her right to recover against the karate school in the event she sustained such an injury."

The claim against the instructor was allowed to stand, as genuine issues of material fact were present about the claim that the contact was intentional.