How to get paid when horseplay is a part of the history for a workers’ comp injury.

There is a news item out of the Business Insurance site discussing the “horseplay doctrine” in the context of a restaurant worker suffering a shoulder injury caused when he raised his arm for protection from ice being thrown by a co-employee. I actually disagree with the characterization that raising one’s arm can cause this injury. I suspect the waiter or server’s shoulder was injured from a wear and tear injury first caused by lifting heavy bus trays and the raising the arm simply put it over the edge of tearing completely or seriously. It should be noted the server did not win his case because of pre-existing shoulder conditions from previous shoulder dislocations.