Novel Measurement of Intradiscal Pressure in Underbody Blast Simulation

Underbody Blast (UBB) events subject vehicle occupants to large accelerations that often result in severe lumbar spine injury. Little knowledge exists on the intervertebral disc response during high-rate vertical accelerative loading. To address this gap, the current study investigates intradiscal pressures under UBB loading utilizing biomechanical testing from: 1) isolated Post Mortem Human Surrogate (PMHS) lumbar spine motion segments (LMS) in a custom-designed drop tower fixture; and 2) whole body (WHBO) PMHS in a custom-designed Vertically Accelerated Load Transfer System. During testing, intradiscal pressures were comparable between the LMS and WHBO tests, with non-fracture cases producing higher average peak pressures than fractured tests. Additionally, WHBO testing demonstrated that upper body posture can influence lumbar pressure responses. The current study evaluates lumbar intradiscal pressure transduction as it relates to vertebral fracture in both component and whole body experiments.