Sports such as hockey and football are not as safe as they look. Players involved in these games are hit all the time. Head injuries and hits can be particularly nasty. Shockbox Head Impact Sensor is designed to help athletes understand when they are getting hit too hard. It has wireless head impact sensors that send alerts to your smartphone when a hit is too hard. It has a working range of 100 meters and 100 hours of battery life.
You will be able to analyze impact and share data with others. The Shockbox Head Impact Sensor has apps for iPhone, Android, and Blackberry. Not super cheap but this could be a lifesaver.