A reclined seating posture is likely to become more prevalent as highly automated vehicles are introduced to roadways. Current human body model (HBM) simulations reveal a high risk of submarining in this posture due to initial rearward pitch of the pelvis. The goal of this study was to assess the kinematics and injuries of the pelvis under lap-belt loading in a reclined seating posture through post-mortem human subject (PMHS) sled tests. Five male PMHS were seated on a semi-rigid seat and reclined to a torso angle of 50 deg. The three-point seat-integrated restraint used in this study was designed to mitigate submarining in a reclined posture. The pelvises of the subjects were initially positioned to a similar angle, but the subjects exhibited variations in kinematics, including the direction of pelvis rotation (forward vs. rearward) throughout the forward excursion. Two subjects sustained pelvis fractures at the right iliac wing between the anterior superior iliac spine and the anterior inferior iliac spine. One subject submarined. The results from this study can be used to better understand potential contributing factors to pelvis injury and submarining in a reclined seating posture. Further, the data can be used to assess and improve the biofidelity of HBMs.
Keywords:
Pelvis; PMHS; Recline; Restraint; Submarining