Awareness affects the response of human subjects exposed to a single whiplash-like perturbation

Siegmund, Gunter P., Sanderson, David J., Myers, Barry S. and Inglis, J. Timothy (2003) Awareness affects the response of human subjects exposed to a single whiplash-like perturbation. Spine, 28 7: 671-679. doi:10.1097/00007632-200304010-00010

Author Siegmund, Gunter P.
Sanderson, David J.
Myers, Barry S.
Inglis, J. Timothy
Title Awareness affects the response of human subjects exposed to a single whiplash-like perturbation
Journal name Spine   Check publisher's open access policy
ISSN 0887-9869
Publication date 2003-04-01
Sub-type Article (original research)
DOI 10.1097/00007632-200304010-00010
Open Access Status Not Open Access
Volume 28
Issue 7
Start page 671
End page 679
Total pages 9
Place of publication Philadelphia, U.S.A.
Publisher Hanley & Belfus
Language eng
Subject 1109 Neurosciences
Abstract Study Design. Human subjects were exposed experimentally to a single whiplash-like perturbation. Objective. To determine how awareness of the presence and timing of a whiplash-like perturbation affects the onset and amplitude of the neck muscle response and the peak magnitude of head and neck kinematics. Summary of Background Data. Although most whiplash injuries are sustained in rear-end collisions, which occur without warning, most studies of whiplash injury have used subjects aware of the imminent perturbation. Methods. Seated subjects (35 women and 31 men) underwent a single forward horizontal perturbation (peak acceleration, 1.5 g). Surface electromyography measured the sternocleidomastoid and cervical paraspinal muscle activity. Three awareness conditions were tested: a countdown for subjects alerted to their perturbation, a perturbation without an alert for subjects who expected it within 60 seconds, and an unexpected perturbation for surprised subjects who were deceived. Results. The muscle and kinematic responses of aware (alerted and unalerted) subjects were not significantly different. Sternocleidomastoid activation occurred 7 ms later in surprised subjects than in aware subjects (P < 0.0002). Cervical paraspinal amplitudes were 260% larger and angular head accelerations in flexion were 180% larger in surprised male subjects than in alerted male subjects. Surprised female subjects exhibited a 25% larger head retraction and a 30% lower forward acceleration of the mastoid process than aware female subjects. Conclusions. The larger retractions observed in surprised females likely produce larger tissue strains and may increase injury potential. Aware human subjects may not replicate the muscle response, kinematic response, or whiplash injury potential of unprepared occupants in real collisions.
Keyword Anticipation
Neck muscles
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Unknown

Document type: Journal Article
Sub-type: Article (original research)
Collections: Excellence in Research Australia (ERA) - Collection
School of Health and Rehabilitation Sciences Publications
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Citation counts: TR Web of Science Citation Count  Cited 57 times in Thomson Reuters Web of Science Article | Citations
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Created: Fri, 06 Mar 2009, 00:39:00 EST by Ms Lynette Adams on behalf of Faculty Of Health Sciences