Rapid, Accurate, Cost-effective Assessment of Blood Biomarkers for Diagnosis of Concussion

The goal of this observational study is to test if a biosensor can accurately measure a blood biomarker in adult patients presenting to the emergency department with concussion. The main questions it aims to answer are: * Does the biosensor measure the blood biomarker of interest with the same accuracy as the current gold-standard assay technique? * Do relationships exist between blood biomarker measurements from the biosensor and any psychological or physical symptoms of concussion? Participants will be asked to provide blood samples at initial visit and 2-, 6-, and 12-weeks after injury while completing questionnaires at each visit, along with a brief (2 min) daily symptom inventory. Researchers will compare the concussion group to a muscle/skeletal injury group to see if measurements from the biosensor are exclusive to concussion.