Abstract: An sensor system measures acceleration and detects impacts. According one embodiment of the present invention, an impact sensor system attaches to a helmet, detects impacts, and displays indications of single and cumulative impacts. Identifying impacts when they occur can help identify players to be screened for concussion or taken out of action before they show symptoms. This can help prevent concussions that result from cumulative hits, which are often more dangerous than those that result from a single hit. The system serves as a continue-to-play decision support aid.