When people think of the type of work disability that may affect first responders, they tend to envision the most obvious physical injuries: gunshots for police officers; burns or smoke inhalation for firefighters; muscle strains and dangerous exposures for EMTs lifting patients or working with those who are extremely ill. But according to recent studies, one of the most insidious dangers faced by first responders is PTSD, or Post Traumatic Stress Disorder. Though PTSD is usually associated with experiencing a…