"Trauma" is an impact injury that occurs and you know it immediately. Usually there is bruising, obvious swelling, deformity or blood. Having pain because you did something funny working out two days ago is not a Trauma in this definition. If you have to think about what it is you might have done, chances are that it was one of the other three things on this checklist that occurred first, then some other activity (bending, twisting, lifting, jumping, running, etc.) made you notice.