A protective impact-absorbing headgear liner and impact sensing system for use with various types of helmets and protective gear or clothing. The lining material has unique impact absorbing properties to additionally protect a wearer from impact related injuries. The headgear liner has a band and crown which are variously shaped and positioned to received impact-absorbing pads. The position of the pockets depends on the helmet style. In one example the liner is a stretchable material. Impact absorbing pads as described herein may be used in a variety of clothing and protective gear to protect from impact injury. Examples are football shoulder ads, thigh pads, bicycle helmets and the like. The liner may also be an expanded foam. A preferred pad material is a gel containing a thermoplastic elastomer. The impact sensing system utilizes an impact sensor assembly to sense the force of impact received and transmit the data to a personal electronics device running an application program to process and display sensor data. Other data such as temperature or the like provided by other ancillary sensors may also be processed by the application program.
