Abstract:
"Effects of Torso-Borne Mass and Loading Severity on Early Response of the Lumbar Spine under High-Rate Vertical Loading"
This study employs a high-fidelity pelvis–lumbar spine finite element model, reconstructed from CT data and scaled to a 50th percentile male, to investigate how varying severities of under-body blast (UBB) loading and added torso-borne mass affect early lumbar spine response under high-rate vertical accelerations. Simulations using LS-DYNA applied both low and high pelvis accelerations—derived from a full-body Hybrid-III model—with and without a 28 kg torso mass. Results reveal that spine deformation patterns progress from flexion at upper levels (L1–L2) through pure compression mid-spine to extension at lower levels (L4–L5), producing an “S”-shaped curvature and suggesting level-dependent injury mechanisms. Under high-severity loading, the spine reaches injurious force and moment thresholds (~10 kN, ~580 N·m) and fails before the torso mass fully engages; under lower severities, torso inertia plays a more significant role. These biomechanical insights into loading modes and spine injury mechanisms can guide the design of protective systems in blast environments.
