Kinematic and Biomechanical Response of Post-Mortem Human Subjects Under Various Pre-Impact Postures to High-Rate Vertical Loading Conditions.

Limited data exist on the injury tolerance and biomechanical response of humans to high-rate, under-body blast (UBB) loading conditions that are commonly seen in current military operations, and there are no data examining the influence of occupant posture on response. Additionally, no anthropomorphic test device (ATD) currently exists that can properly assess the response of humans to high-rate UBB loading. Therefore, the purpose of this research was to examine the response of post-mortem human surrogates (PMHS) in various seated postures to high-rate, vertical loading representative of those conditions seen in theater. In total, six PMHS tests were conducted using loading pulses applied directly to the pelvis and feet of the PMHS: three in an acute posture (foot, knee, and pelvis angles of 75°, 75°, and 36°, respectively), and three in an obtuse posture (15° reclined torso, and foot, knee, and pelvis angles of 105°, 105°, and 49.5°, respectively). Tests were conducted with a seat velocity pulse that peaked at ~4 m/s with a 30-40 ms time to peak velocity (TTP) and a floor velocity that peaked at 6.9-8.0 m/s (2-2.75 ms TTP). Posture condition had no influence on skeletal injuries sustained, but did result in altered leg kinematics, with leg entrapment under the seat occurring in the acute posture, and significant forward leg rotations occurring in the obtuse posture. These data will be used to validate a prototype ATD meant for use in high-rate UBB loading scenarios.

Safety, usability, and independence for wheelchair-seated drivers and front-row passengers of private vehicles: a qualitative research study.

A survey and observational study was conducted with 29 people who remain seated in their wheelchair when driving (21) or riding as a front-row passenger (8) in their personal vehicle. Each subject was observed and surveyed in their own personal vehicle that has been modified for use by occupants seated in wheelchairs. Our survey obtained responses on issues related to occupant restraint (seat belt) system usage, wheelchair securement device usage, and perception of personal safety while riding in a vehicle. Usability and accessibility issues related to seat belt and automated (docking) wheelchair securement technology were revealed, suggesting that wheelchair-seated occupants travel with a higher risk of serious injury in vehicle crashes than front-row occupants seated in original equipment manufacturer (OEM) vehicle seats and using OEM seat belts. Study results also indicate the need for improved torso support for many wheelchair-seated drivers to maintain a posture that allows for effective vehicle control. Study results demonstrate the need for innovative passive restraint technologies that provide postural support during normal vehicle operation and improved occupant restraint during crash conditions for people who drive while seated in their wheelchairs.