Accession Number:

ADA181327

Title:

Neck Muscle Endurance and Fatigue as a Function of Helmet Loading: The Definitive Mathematical Model

Descriptive Note:

Annual rept. (Final) 1 Jun 1980-15 Jun 1984

Corporate Author:

WRIGHT STATE UNIV DAYTON OH

Report Date:

1984-09-01

Pagination or Media Count:

89.0

Abstract:

A series of experiments were conducted in which the neck muscles of volunteer subjects were dynamically and statically loaded by systematic variations of twenty-four headgear configurations consisting of eight different centers-of-gravity CGs times three different weights. Six subjects would rotate their heads laterally from side-to-side for 30 min with each of the headgear loading combinations. Immediately thereafter, the subject would position his head in an isometric head dynamometer and exert a sustained right lateral neck contraction or forward neck contraction at 70 of his maximum strength, during which endurance time to fatigue was recorded. The results indicate that the computer model makes reasonable predictions within the boundary conditions. Input data outside the boundary conditions is rejected. The assumption of insensitivity to vertical loading is demonstrated. The assumption of bilateral symmetric response was confirmed for the 1.45 kg and 2.27 kg helmet loads. However, this assumption was not confirmed for the 4.09 kg helmet load. It is concluded from the computer model that afterward, midline loading is the optimal CG location i.e. maximal endurance for heavier helmets in the 3-4 kg range.

Subject Categories:

  • Stress Physiology
  • Human Factors Engineering and Man Machine Systems

Distribution Statement:

APPROVED FOR PUBLIC RELEASE