US Patent 7430767 Protective helmet with motion restrictor

A protective helmet, which includes a motion restrictor device, is disclosed which has at least one strut member associated with the helmet and a harness assembly, and the at least one strut member includes a locking assembly associated with the strut member, which upon a predetermined force being sensed by a force sensor, stops substantially all relative motion between the ends of the strut member and the predetermined force is substantially transferred from the helmet to the harness assembly.