Accession Number:

ADA169563

Title:

Analysis of Head and Neck Dynamic Response of the U.S. Adult Military Population.

Descriptive Note:

Annual technical rept. 3 (Final) 1 Oct 84-1 Feb 86,

Corporate Author:

MICHIGAN UNIV ANN ARBOR TRANSPORTATION RESEARCH INST

Personal Author(s):

Report Date:

1986-04-15

Pagination or Media Count:

135.0

Abstract:

Mechanisms of headneck dynamic response were investigated for NBDL volunteer data in -Gx and Gy acceleration vectors with the MVMA 2-D and VOM 3-D Crash Victim Simulation models. Computer simulation of human subject response yielded mechanical constants pertinent to the design of a Biofidelic Manikin BFM. Improved biofidelity for a two-joint neck model was achieved by relocating the lower neck pivot point inferior and posterior to anatomic T1. In -Gx, the magnitude and duration for condyles extension, in particular, was improved while satisfactory acceleration response was maintained. Exercising the neck model at -6Gx and -15Gx showed that it was necessary to use nonlinear stiffnesses for the lower neck joint in flexion. Two modes of extension motion at the occipital condyles were seen in the volunteer subjects. The first mode was extension with rebound some subjects demonstrating flexion. The second mode was peak extension followed by further increase in the extension motion. The two modes of condyles extension appear to depend on some pre-test condition - probably muscle tensing - since the short duration of the head and neck motion in a test 300 ms should not allow muscular reaction beginning after the onset of the test to be a factor. Simulations with a model that has passive neck elements give only the extension with rebound response, i.e., mode one response. Thus, on the basis of simulations, it can probably be said that mode one response results for subjects who are not pretensed and mode two response results for pre-tensed subjects. Keywords Anthropomorphic dummy Impact Manikin and Neck model.

Subject Categories:

  • Stress Physiology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE