Influence of Pilot's Lumbar Lordosis on the Sustainability for Ejection Impact

• Main Authors: Chen Chung Chun, 陳仲鈞
• Other Authors: Chen Hsiang Ho
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/89782799832134683071

碩士 === 義守大學 === 工業管理學系 === 90 === In order to understand the influences of pilot’s lumbar lordosis on the sustainability for ejection impact, this study measured the characteristic angles of lumbar lordosis from 112(?) helicopter crews of the ROC Army. Two lumbar lordotic angles were measured: the first measure was between L1 and L5 (LLAΙ); the second one was between L2 and L5 (LLAⅡ). The mean values of LLAΙand LLAⅡ were 31.42 ± 10.11 o and 34.16 ± 9.39 o , respectively. Besides, the lumbosacral angle and sacral inclination angle were 14.05 ± 5.84 o and 42.58 ± 9.15 o, respectively. No significant difference was noted in lumbar lordotic angle (LLAΙ) between helicopter crews and normal adults, but there was a statistically significant difference between helicopter crews and western normal males (LLAⅡ). This study also designed a lumbar model with variable lordosis for a 50 %ile dummy, and used it to be the subject in ejection experiments. The results of the ejection experiment showed that the acceleration for the lumbar with normal lordosis was smaller than the more lordotic or straight lumbar. The results also revealed that increasing of the abdominal pressure had a potential to decrease the loads on the lumbar spine. In addition to ejection experiments, this study also established a finite element spine model to simulate a thoraco-lumbar spine under ejection impacts. The results of FE simulation showed that both of a larger lorditic angle and a higher ejecting onset rate increased the stress distributed on lumbar spine. To summarize the results of experiments and simulation may conclude that the lumbar lordosis will moderately vary the lumbar loading during sustaining ejection impact, and further studies are needed to benefit the pilot’s safety.