High-speed 3-D kinematics from whole-body lateral impact sled tests

While lateral impact sled studies have been conducted to determine injuries, injury mechanisms, and derive human tolerance using post mortem human subject (PMHS) for the chest and pelvis regions of the human body, there is a paucity of three-dimensional (3-D) motions at high-speeds. Since out-of-position occupants respond with 3-D motions even under pure frontal and lateral impacts, it is important to determine such kinematics at high-speeds in the temporal domain. Consequently, the objective of the study was to determine lateral impact-induced 3-D temporal motions at 1,000 frames per sec. PMHS were screened, seated on a sled, restrained using belt systems, and 13.5 g lateral impact acceleration was applied. Retroreflective photographic markers were placed at various locations including the head, first thoracic vertebra, sacrum, dorsal spine, and sled. 3-D coordinates of the anatomical locations of PMHS, fiducially placed markers, and sled were obtained pretest and post test. Kinematics of the head with respect to sled, head with respect to first thoracic vertebra, and first thoracic vertebra with respect to sled in the Cartesian system of reference were determined using a nine-camera system. Head and first thoracic vertebral kinematic data are reported in the paper. 3-D motions induced from lateral impacts supplement sensor-based data for improved crashworthiness evaluations.