航天医学与医学工程

目的 探究增大弹射座椅靠背角度后对不同体型飞行员体压分布的影响，为弹射座椅的设计、飞行训练，以及制订缓解肌肉疲劳的策略提供依据。方法 将战斗机男性飞行员按体重指数（BMI）分为正常体型组和超重组，利用体压分布测量系统分别测试20°、33°两种座椅靠背角度下共41名飞行员坐姿压力分布。分析不同座椅靠背角度对坐姿舒适性的影响。结果 不同座椅靠背角度下，不同体型飞行员体压分布差异具有统计学意义。相比20°座椅，33°座椅条件下坐垫接触面积更大[F(1,78)=40.281,P<0.001]，平均压力及平均压力梯度更小[F(1,78)=32.030,P<0.001;F(1,78)=12.594,P<0.001]，背靠的平均压力梯度、最大压力及最大压力梯度均明显减小，差异具有统计学意义[F(1,78)=10.516,P=0.002;F(1,78)=26.803,P<0.001;F(1,78)=4.918,P=0.029）]。此外，BMI超重者与坐垫的接触面积[F(1,78)=21.038,P<0.001]以及背靠的接触面积[F(1,78)=8.301,P=0.005]均明显大于正常体重组。角度和BMI未观察到显著交互作用。结论 在弹射座椅靠背角度更大时，平均压力及平均压力分布梯度降低，人体压力分布更均匀，舒适性更高，不同体型群体在不同弹射座椅角度下的坐垫与背靠压力分布差异可为座椅的适体性设计提供重要依据。

Objective To investigate the effects of increasing the ejection seat backrest angle on the body pressure distribution of pilots of different body types, and to provide a basis for the design of ejection seats, flight training, and the development of strategies to alleviate muscle fatigue. Methods Male fighter pilots were divided into normal and overweight groups according to their body mass index(BMI), and a total of 40 pilots were tested for the distribution of sitting pressure under the two seat inclination angles of 20°and 33°by using the body pressure distribution measurement system. The effects of different seat inclination angles on sitting comfort were also analyzed. Results The pressure distributions of pilots with different body types were significantly different at different seat inclination angles. Compared with the 20°seat, the 33°seat condition had a larger cushion contact area [F(1,78) = 40.281, P <0.001], a smaller average pressure and average pressure gradient[F(1,78) =32.030, P <0.001; F(1,78) = 12.594, P <0.001], and significantly reduced average, maximum pressure, and maximal pressure gradients for the backrest [F(1,78)=10.516, P =0.002; F(1,78) =26.803, P <0.001; F(1,78)=4.918, P = 0.029, respectively]. In addition, overweight individuals with BMI had a notable increase in the cushion contact area [F(1,78) =21.038, P <0.001] and the backrest contact area [F(1,78)=8.301, P =0.005]. No significant interaction was observed for angle and BMI. Conclusion An increased seat inclination angle results in a more uniform distribution of pressure across the human body, thereby increasing comfort. Moreover, the disparities in pressure and backrest distribution across disparate body types at varying seat angles provide a vital foundation for the optimized design of seating.