Theoretical and Mechanical Models of the Human Neck

The project has been concerned with possible constraint systems to protect the head of an aircraft occupant against violent rotation about the torso and subsequent loss of consciousness during emergency landings and survivable crashes. The restraint concept that has been tested is an inflatable collar to limit head motion. The collar would fit under the chin and cushion the impact of the chin on the thorax during hyperflexion of the neck. During the first year of the contract, an airbag was tested using a single-degree-of- freedom mechanical system. An anthropometric dummy head was mounted on a rigid bar that simulated the neck. The second part of the contract has been devoted to further exploration of this concept. A mechanical model has been built to better simulate the human neck. This model allows stretching of the neck and relative angular motion between the head and neck similar to head rotation about the occipital condyles.