“In the national study, between 11% and 27% of healthy college athletes with no history of a recent concussion reported combinations of symptoms that met criteria for post-concussion syndrome (PCS) as defined by an international classification system.”
Up to a quarter of healthy athletes with no recent head injury already meet the criteria for post-concussion syndrome. Tired, stressed college students report the same symptoms. A symptom checklist can’t tell a hit from a bad week. That matters when it decides who goes back on the field.