Any injury occuring while enjoying oneself, e.g. bumping your head on the headboard, a sunburn from sitting at the beach, skateboarding accidents, poor sense of smell due to cocaine use...
An injury directly related to the act of 'throwing down' (referred to as 'dancing' in general culture) to dubstep. Most common TRI's are those of the neck, back and feet. Severe TRI's may require medical attention.
"I was throwing down hard at Figure on the weekend and when "Aliens" dropped I copped a mad TRI (Throwdown Related Injury)" to my neck - had to ice it the next day, but it's feeling better now