Head support/spine offloading ejection seat insert

A seat insert insertable within the existing seat of a vehicle for maintaining a crew member of the vehicle in a forward posture during high G acceleration, comprising:

• (a) an elongated head support member having an upper end and a lower end, said head support member for supporting the crew member's head during a forward leaning posture;
• (b) a thoracic back plate having a front surface with substantially the same curvature as the thoracic spine of the crew member, said thoracic back plate, having an upper end being hingedly attached to the lower end of said head support member;
• (c) a lumbar back plate having a front surface with substantially the same curvature as the lumbar spine of the crew member, said lumbar back plate having an upper end being attached to the lower end of the thoracic back plate, means for providing relative yaw motion between said lumbar back plate and said thoracic back plate, said lumbar back plate and thoracic back plate serving to support the lumbar spine and thoracic spine in their natural curvatures, thereby minimizing the risk of injury due to non-uniform vertebrae interface loads;
• (d) two forwardly extending hip extensions, each connected to a respective side of the lumbar back plate;
• (e) a seat pan base assembly which is contoured to fit upon the seat of the vehicle and about the crew member's buttocks, said seat pan base assembly including means for pivotly connecting it to said hip extensions thereby allowing transference of g-induced loads from the hip extensions to the seat pan base assembly;
• (f) a head support member restraint cord connected at a top end to said head support member and at a bottom end to said seat pan base assembly having a sufficient length to restrain head support member movement during a crew member's forward lean;
• and
• (g) a chest plate strapped to said thoracic back plate for securing said crew member to said seat insert and for uniformly distributing loads over the crew member's rib cage due to g-induced body weight and during a forward leaning posture.