B. M. Bowman

A Biomechanical Analysis of Head Impact Injuries to Children

Head-first free-falls of 30 children, 1-10 years old and one adult, 21 years old, were studied to determine fall circumstances and injuries sustained. The falls of six children and one adult were simulated using the MVMA Two-Dimensional Crash Victim Simulator computer model. The data shows that head-first falls of children onto rigid surfaces from heights as low as 2 meters can result in serious injuries. Conservative head injury tolerance limits are estimated to be 200-250g for peak head acceleration. /Author/

The MVMA Two-Dimensional Crash Victim Simulation

This paper presents the various features and operational properties of a two-dimensional mathematical model of crash victim motions. The features of this model include: (1) An eight mass representation of the human body where contact between the crash victim and the vehicle is represented in terms of independent force-deformation properties of the victim and the vehicle. (2) An extensible multijoint neck and a realistically flexible shoulder joint. (3) A real- line representation of the vehicle interior or exterior where shape is given as a network of points. (4) Specific predictive restraint device submodels for the airbag, the energy absorbing steering column, and a slipping, energy absorbing three-point-belt restraint system. (5) A flexible output package including graphics, an injury criteria monitor, and a variety of options for listing, deleting, and comparing selected output variables.

SIMULATION ANALYSIS OF HEAD AND NECK DYNAMIC RESPONSE

The objectives of this study are to quantify the biomechanical properties of the human neck which govern head and neck dynamic response and to establish the mechanisms responsible for primary aspects of response. Computer simulations with the MVMA 2-D and VOM 3-D occupant dynamics models were performed using head and neck sled input response data from human subjects at the Naval Biodynamics Laboratory for input and comparison. Predicted dynamic response data and preliminary values for biomechanical parameters in a three-dimensional head/neck model capable of accurately simulating response for minus X, plus Y, and minus X plus Y sled acceleration vectors are presented. The established analytical model should accurately predict head and neck responses in simulations of real-world automobile crashes where direct head impact is not involved.

Whole-body human surrogate response to three-point harness restraint

The general objective of the Whole-Body Response (WBR) research program was to generate data on the kinematics and response of human surrogates in a realistic automobile impact environment. The program used a test configuration consisting of an idealized hard seat representation of a car seat with a three-point harness restraint system. Three different severity levels of crash test conditions were used. The human surrogates tested in this program were fifteen male cadavers, a Hybrid II (Part 572) Anthropomorphic Test Device and a Hybrid III ATD recently developed by General Motors. In addition, mathematical simulations of the response and kinematics of a 50th percentile male occupant were performed at the three levels of crash severity, using the MVMA Two-Dimensional Crash Victim Simulator.

Simulation of head/neck impact responses for helmeted and unhelmeted motorcyclists

The purpose of this study was to assess, by use of computer simulations, the effectiveness of motorcycle helmets in reducing head and neck injuries in motorcyclist impacts. The computer model used was the MVMA Two-Dimensional Crash Victim Simulator. The study investigated a wide variety of impact conditions in order to establish a broad overall view of the effectiveness of helmets. It was found that helmet use invariably reduces dynamic responses which have a role in producing head injury and, in addition, almost always reduces the severity of neck response as well. For no configuration or condition does the helmet greatly increase the likelihood of neck injury. Thus, these simulations of a wide spectrum of motorcyclist impacts provide further evidence that helmet use significantly reduces the likelihood and severity of both head and neck injuries.

Motion Measurement Of A Rigid Body In Three Dimensions

A technique has been developed for measuring the six possible independent motions (three translational and three rotational) of a rigid body. The technique was developed specifically to measure head motions of an anthropometric dummy during simulated oblique and lateral crashes using an impact sled. Under such test conditions, body motions may be highly non-symmetric making a complete three-dimensional analysis necessary.