Height and In-Flight Low Back Pain Association Among Military Helicopter Pilots

Abstract

Low back pain (LBP) among helicopter pilots is a well-recognized problem, with prevalence ranging from 61 to over 80%. Studies indicate association with total flight hour (TFH) exposure and lack of association with height or body mass index (BMI); however, those that have excluded pilots with back injuries unrelated to flying are limited. Surveyed regarding LBP were 1028 U.S. Navy helicopter pilots. Of the 648 (63%) respondents, 83 pilots, or 12.9%, who reported nonflying related back injuries and those without necessary data were excluded, yielding N = 554. Case-control analysis was performed with logistic regression for height, BMI, and TFH on significant LBP (defined as > 30% of each flight) presence versus absence with Chi-square on the median split of each and ANOVA to include airframes. Height was a positive predictor for significant LBP among all subjects (OR: 1.7), with the strongest association among male pilots (OR: 2.1). BMI, THF, and airframe (H-60, TH-57, H-53, and H-46) were not associated. These results imply that ergonomic stressors that adversely impact lumbar symmetry may be a predominant factor in LBP during flight. Significant prevalence rates may persist in the absence of design enhancements that mitigate these stressors. Height was a significant predictor for in-flight LBP among U.S. Navy helicopter pilots studied and BMI, TFHs, and airframe were not. For every 1" increase among male pilot height values, the odds of experiencing significant LBP in flight increased by 9.3%, with those equal/taller than median (71 in.) having over twice the odds compared with those shorter.