Systems, methods, and apparatus are described that employ a fast concussion model usable to detect occurrence of traumatic events that can contribute to mild traumatic brain injury (mTBI) and to assess the risk that mTBI has occurred or is likely to occur should further traumatic events occur. A method includes receiving motion data related to a head acceleration event from sensors configured to detect head motion of a subject, using the motion data to obtain an estimate of axon signal dysfunction affecting a component of the subject's brain as a result of the head acceleration event, determining a Neurologic Injury Measure (NIM) from the estimate of axon signal dysfunction, and generating a probability that the subject has been concussed by the head acceleration event based on the NIM. The estimate of axon signal dysfunction may be based on strain at nodes of Ranvier in the component of the subject's brain. CI° c~c f0
BRAIN INJURY MONITORING SYSTEM