Disclosed herein are methods, and kits for use in said methods, that aid in the diagnosis and evaluation of a subject that has sustained an orthopedic injury and sustained or may have sustained an injury to the head, such as mild traumatic brain injury (TBI), using ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), glial fibrillary acidic protein (GFAP), or a combination thereof. Also disclosed herein are methods, and kits for use in said methods, that aid in determining whether a subject that has sustained an orthopedic injury and sustained or may have sustained an injury to the head would benefit from and thus receive an imaging procedure, such as MRI or head computerized tomography (CT) scan based on the levels of GFAP and/or UCH-L1. These methods involve detecting levels and changes in levels of GFAP and/or UCH-L1 in biological samples taken from a subject at time points within 48 hours after the subject has sustained or may have sustained an injury to the head.