Human pelvis injury risk curves from underbody blast impact. BMJ Mil Health 2023 Oct;169(5):436-442
Date
10/30/2021Pubmed ID
34711674DOI
10.1136/bmjmilitary-2021-001863Scopus ID
2-s2.0-85138577083 (requires institutional sign-in at Scopus site) 5 CitationsAbstract
INTRODUCTION: Underbody blast loading can result in injuries to the pelvis and the lumbosacral spine. The purpose of this study was to determine human tolerance in this region based on survival analysis.
METHODS: Twenty-six unembalmed postmortem human surrogate lumbopelvic complexes were procured and pretest medical images were obtained. They were fixed in polymethylmethacrylate at the cranial end and a six-axis load cell was attached. The specimens were aligned in a seated soldier posture. Impacts were applied to the pelvis using a custom vertical accelerator. The experimental design consisted of non-injury and injury tests. Pretest and post-test X-rays and palpation were done following non-injury test, and after injury test medical imaging and gross dissections were done. Injuries were scored using the Abbreviated Injury Scale (AIS). Axial and resultant forces were used to develop human injury probability curves (HIPCs) at AIS 3+ and AIS 4 severities using survival analysis. Then ±95% CI was computed using the delta method, normalised CI size was obtained, and the quality of the injury risk curves was assigned adjectival ratings.
RESULTS: At the 50% probability level, the resultant and axial forces at the AIS 3+ level were 6.6 kN and 5.9 kN, and at the AIS 4 level these were 8.4 kN and 7.5 kN, respectively. Individual injury risk curves along with ±95% CIs are presented in the paper. Increased injury severity increased the HIPC metrics. Curve qualities were in the good and fair ranges for axial and shear forces at all probability levels and for both injury severities.
CONCLUSIONS: This is the first study to develop axial and resultant force-based HIPCs defining human tolerance to injuries to the pelvis from vertical impacts using parametric survival analysis. Data can be used to advance military safety under vertical loading to the seated pelvis.
Author List
Yoganandan N, Moore J, Humm JR, Baisden JL, Banerjee A, Pintar FA, Barnes DR, Loftis KLAuthors
Anjishnu Banerjee PhD Associate Professor in the Data Science Institute department at Medical College of WisconsinFrank A. Pintar PhD Chair, Professor in the Biomedical Engineering department at Medical College of Wisconsin
Narayan Yoganandan PhD Professor in the Neurosurgery department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
CadaverHumans
Pelvis
Posture
Probability
Radiography
