Open ears, close mouth. Just listen. It sounds lame, but it's really the most relevant exercise you can engage in with trauma patients as a med student. Trauma is complicated and really digging it apart requires a really nuanced touch. As an intern closing out my first year, I don't really try to go much beyond this. It's beyond your expertise and the risk of harm is greater than the potential for benefit at this stage in your education. You just don't have the skillset to talk about childhood rape or physical abuse at this stage.