Citation

Jenny C, Bertocci G, Fukuda T, Rangarajan N, Shams T. J. Neurotrauma 2016; 34(8): 1579-1588.

Affiliation

GESAC, Silver Spring, Maryland, United States ; posthumus@posthumus.com.

Copyright

(Copyright © 2016, Mary Ann Liebert Publishers)

DOI

10.1089/neu.2016.4687

PMID

27931172

Abstract

Controversy exists regarding whether violent shaking is harmful to infants in the absence of impact. In this study, our objective was to characterize the biomechanical response of the infant head during shaking through use of an instrumented anthropomorphic test device (commonly referred to as a 'crash test dummy' or infant surrogate) representing a human infant and having improved biofidelity. A series of tests were conducted to simulate violent shaking of an infant surrogate. The Aprica 2.5 infant surrogate represented a 5th percentile Japanese newborn. A 50th percentile Japanese adult male was recruited to shake the infant surrogate in the sagittal plane. Tri-axial linear accelerometers positioned at the center of mass and apex of the head recorded accelerations during shaking. Five shaking test series, each 3 to 4 seconds in duration, were conducted. Outcome measures derived from accelerometer recordings were examined for trends. Head and neck kinematics were characterized during shaking events; mean peak neck flexion was 1.98 radians (113 degrees) and mean peak neck extension was 2.16 radians (123 degrees). The maximum angular acceleration across all test series was 13,260 radians/second2. Peak angular velocity was 105.7 radians/second. Acceleration pulse durations ranged from 72.1 milliseconds to 168.2 milliseconds. Using a biofidelic infant surrogate, we found higher angular acceleration and higher angular velocity than previously reported during infant surrogate shaking experiments.

FINDINGS highlight the importance of surrogate biofidelity when investigating shaking.

Language: en