Dynamic Response of the Thoracolumbar and Sacral Spine to Simulated Underbody Blast Loading in Whole Body Post Mortem Human Subject Tests

• Published in: Annals of biomedical engineering Vol. 49; no. 11; pp. 3046 - 3079
• Main Authors: Sherman, Donald, Somasundaram, Karthik, Begeman, Paul, Foley, Sierra, Greb, Jason, Bir, Cynthia, Demetropoulos, Constantine K., Cavanaugh, John M.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.11.2021; Springer Nature B.V
• Subjects: Acceleration; Accelerometers; Aged; Biochemistry; Biological and Medical Physics; Biomechanics; Biomedical and Life Sciences; Biomedical engineering; Biomedical Engineering and Bioengineering; Biomedicine; Biophysics; Blast Injuries; Blast loads; Cadaver; Classical Mechanics; Deceleration; Dynamic response; Engineering; Explosions; Human subjects; Humans; Injuries; Injury prevention; Laboratories; Lumbar Vertebrae - injuries; Lumbosacral Region - injuries; Male; Middle Aged; Pelvis; Personal Protective Equipment; Protective equipment; Sacrum; Sacrum - injuries; Simulation; Skull; Sleds; Spine; Spine (lumbar); Spine (thoracic); Thoracic Vertebrae - injuries; Trend analysis; Underbodies; Vehicles; Velocity; WIAMan Biomechanics; Thoracic and sacral spine; Post mortem human subject sled test; Underbody blast; Impact biomechanics
• ISSN: 0090-6964; 1573-9686; 1573-9686
• DOI: 10.1007/s10439-021-02753-8

Fourteen simulated underbody blast impact sled tests were performed using a horizontal deceleration sled with the aim of evaluating the dynamic response of the spine in under various conditions. Conditions were characterized by input (peak velocity and time-to-peak velocity for the seat and floor), seat type (rigid or padded) and the presence of personnel protective equipment (PPE). A 50% (T12) and 30% (T8) reduction in the thoracic spine response for the specimens outfitted with PPE was observed. Longer duration seat pulses (55 ms) resulted in a 68–78% reduction in the magnitude of spine responses and a reduction in the injuries at the pelvis, thoracic and lumbar regions when compared to shorter seat pulses (10 ms). The trend analysis for the peak Z (caudal to cranial) acceleration measured along the spine showed a quadratic fit ( p  < 0.05), rejecting the hypothesis that the magnitude of the acceleration would decrease linearly as the load traveled caudal to cranial through the spine during an Underbody Blast (UBB) event. A UBB event occurs when an explosion beneath a vehicle propels the vehicle and its occupants vertically. Further analysis revealed a relationship ( p  < 0.01) between peak sacrum acceleration and peak spine accelerations measured at all levels. This study provides an initial analysis of the relationship between input conditions and spine response in a simulated underbody blast environment.