Analysis of biomechanical and ergonomic aspects of the cervical spine in F-16 flight situations.

With the help of a biomechanical neck model, several normal postures of an F-16 pilot were analysed. Measurements of accelerations and head positions were obtained during four flights, including simulated air combat. With the help of a model, muscle forces and joint reaction forces in the neck were estimated. Although at the present stage of research results of calculations must be interpreted carefully, conclusions can be drawn with respect to sitting posture, head position and helmet devices. The backward inclined back rest of the F-16 chair decrease the lordosis of the cervical spine, resulting in reduced calculated forces in the lower cervical spine. In high load situations, calculated maximal forces are of the same order of magnitude as failure loads of vertebrae and estimations of maximum muscle forces. The calculated neck load is increased substantially by the helmet and helmet-mounted devices. This load can be reduced by lightening the helmet or shifting the centre of mass of the helmet backwards.