The Characterization of Spinal Compression in Various-Sized Human and Manikin Subjects During +Gz Impact

Abstract

Background: During +Gz impacts such as those encountered during ejection, the human torso and spine compress or slump due to the inertial forces acting on the body. Spinal compression can be characterized by a second-order differential equation involving coefficients such as damping ratio, natural frequency and spring constant. Objective: To characterize spinal compression resulting from +Gz impacts and determine how well test manikins replicate responses of similar size humans. Methods: Various-sized humans were tested with identical conditions on a vertical deceleration tower. Seat and chest accelerations were used to calculate the damping ratio, natural frequency and spring constant of each subject. Data analysis was performed to determine what correlations may exist between spinal compression and sitting height, torso mass, gender or vibration parameters. Results: Results show that spinal compression had no significant correlation to sitting height, torso mass, gender, damping ratio, undamped natural frequency or spring constant.

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Document Details

Document Type
Technical Report
Publication Date
Oct 01, 2005
Accession Number
ADA446499

Entities

People

  • Erin Caldwell
  • John Plaga

Organizations

  • Air Force Research Laboratory

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Abstracts
  • Air Force
  • Air Force Research Laboratories
  • Aircrafts
  • Compression
  • Data Analysis
  • Deceleration
  • Ejection
  • Ejection Seats
  • Frequency
  • Government Procurement
  • Governments
  • Information Exchange
  • Military Research
  • Resonant Frequency
  • Statistical Analysis
  • Vibration

Readers

  • Brain and Cognitive Science; Experimental Psychology; Cognitive Neuroscience
  • Explosive Engineering.
  • Structural Dynamics.