Neck Orientation During G-Forces
How a pilot is oriented or where the pilot is looking largely impacts the severity of cervical musculoskeletal loading on the neck under G-forces.
A study conducted by Dr. Zhou in the NJIT Department of Biomedical Engineering investigated the effects of two flight postures commonly experienced by fighter pilots during aerial combat maneuvering: the look-ahead and the check-6. A dynamic muscle-fatigue model based on a fatigue-rest-recovery mechanism was used to predict muscle fatigue response to arbitrary neural excitations. The neck biodynamic responses to the applied G-loading were obtained and compared between the look-ahead and check-6 postures. There was a significant increase in neck strain during the check-6 posture when compared to the look-ahead. The check-6 posture poses a much greater challenge to neck muscle force-generation and induces quicker and more intense fatigue (especially during sustained G-loading).
For pilots who sustain G-forces it is important to note that the neck/back muscular activation pattern decreases throughout the engagement due to muscular fatigue, while the aircraft loading/acceleration remains constant.
Of the subjects, those who suffered from chronic degenerative processes of the vertebrae resulted from repeated exposure to G-forces. Knowing the muscular forces, muscular activation level, fatigue limitations, and joint reaction forces of the neck and back can help predict which movement patterns are likely to induce injury during combat maneuvering. This evidence supports the need for intensive neck strengthening/preventative/rehabilitative/range of motion protocols in the fighter pilot community.