座椅椅背倾角对飞行员颈部损伤的影响

Objective To study the effect of seat back angle (SBA) on neck injury of pilots. Methods Based on head-neck multi-body dynamic model, dynamic simulations were conducted on 17°and 22° SBA under two typical flight conditions (sharp turning and stable hovering). The maximum forces of neck muscle and time-varying curves of axial force, bending moment were obtained. Neck injury was evaluated and predicted based on neck injury criterion (NIC), N_ij criterion and abbreviated injury scale (AIS). Results Under the same flight condition, the neck was under flexion at 17° SBA, and the trapezius and splenius capitis were stretched. While the neck was under extension at 22° SBA, and the lingualis was stretched. The muscle force of the trapezius at 17° SBA was the maximum. For the same segment, the axial force at 17° SBA was higher than that at 22° SBA, while the extension moment at 22° SBA was larger than the flexion moment at 17° SBA. The axial force and moment under all flight conditions did not exceed the defined injury assessment reference values, and no damage to the cervical spinal cord would occur. The N_ij of C7-T1 segment at 22° SBA under sharp turning condition was the maximum under all simulated conditions, reaching the critical value in aviation field, and the probability of moderated injury and serious injury for the neck was 3. 93% and 2. 63%, respectively. Conclusions The results in this study will provide support for evaluating the effect of SBA on neck injury of pilots.