Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control, School of Mechanical Engineering, Tianjin University of Technology, Tianjin, 300384, China.
National Demonstration Center for Experimental Mechanical and Electrical Engineering Education, Tianjin, 300384, China.
Med Biol Eng Comput. 2023 Sep;61(9):2255-2268. doi: 10.1007/s11517-023-02817-y. Epub 2023 Mar 28.
To determine the effect of muscle activation on the dynamic responses of the neck of a pilot during simulated emergency ejections. A complete finite element model of the pilot's head and neck was developed and dynamically validated. Three muscle activation curves were designed to simulate different activation times and levels of muscles during pilot ejection: A is the unconscious activation curve of the neck muscles, B is the pre-activation curve, and C is the continuous activation curve. The acceleration-time curves obtained during ejection were applied to the model, and the influence of the muscles on the dynamic responses of the neck was investigated by analyzing both angles of rotation of the neck segments and disc stresses. Muscle pre-activation reduced fluctuations in the angle of rotation in each phase of the neck. Continuous muscle activation caused a 20% increase in the angle of rotation compared to pre-activation. Moreover, it resulted in a 35% increase in the load on the intervertebral disc. The maximum stress on the disc occurred in the C4-C5 phase. Continuous muscle activation increased both the axial load on the neck and the posterior extension angle of rotation of the neck. Muscle pre-activation during emergency ejection has a protective effect on the neck. However, continuous muscle activation increases the axial load and rotation angle of the neck. A complete finite element model of the pilot's head and neck was established and three neck muscle activation curves were designed to investigate the effects of muscle activation time and level on the dynamic response of the pilot's neck during ejection. This increased insights into the protection mechanism of neck muscles on the axial impact injury of the pilot's head and neck.
为了确定肌肉激活对飞行员在模拟紧急弹射过程中颈部动态响应的影响。建立了飞行员头部和颈部的完整有限元模型，并对其进行了动态验证。设计了三种肌肉激活曲线来模拟飞行员弹射过程中不同的肌肉激活时间和水平：A 是颈部肌肉的无意识激活曲线，B 是预激活曲线，C 是连续激活曲线。将弹射过程中获得的加速度-时间曲线应用于模型，通过分析颈部各节段的旋转角度和椎间盘的应力，研究了肌肉对颈部动态响应的影响。肌肉预激活减少了颈部各阶段旋转角度的波动。与预激活相比，连续肌肉激活导致旋转角度增加 20%。此外，它导致椎间盘上的负载增加 35%。椎间盘上的最大应力出现在 C4-C5 阶段。连续肌肉激活增加了颈部的轴向负荷和颈部后伸旋转角度。紧急弹射过程中的肌肉预激活对颈部具有保护作用。然而，连续的肌肉激活会增加颈部的轴向负荷和旋转角度。建立了飞行员头部和颈部的完整有限元模型，并设计了三种颈部肌肉激活曲线，以研究肌肉激活时间和水平对弹射过程中飞行员颈部动态响应的影响。这增加了对颈部肌肉在飞行员头部和颈部轴向冲击损伤中的保护机制的了解。
