Trauma - it catches you by surprise, in bizarre fashion with unexpected costs. Trauma often sounds like a recipe for disaster, but it doesn't have to be. There's nothing you can do to prevent trauma; accidents happen, things go wrong, elbows are slammed into faces, and no plan of yours could have prevented this.
Yes, an elbow was slammed into my husband's face while playing a pickup game of soccer. Sometimes to stay fit, these things happen. I've had sufficient casualties as a runner, so I can empathize.