Cervical neural space narrowing during simulated rear crashes with anti-whiplash systems
From: Eur Spine J. 2012 Jan 24. [Epub ahead of print]
Chronic radicular symptoms have been documented in whiplash patients, potentially caused by cervical neural tissue compression during an automobile rear crash. The goals of this study were to determine neural space narrowing of the lower cervical spine during simulated rear crashes with whiplash protection system and active head restraint and to compare these data to those obtained with no head restraint. We extrapolated our results to determine the potential for cord, ganglion, and nerve root compression.
The model, consisting of a human neck specimen within a BioRID II crash dummy, was subjected to simulated rear crashes in a whiplash protection system seat (n = 6, peak 12.0 g and ΔV 11.4 kph) or active head restraint seat and subsequently with no head restraint (n = 6, peak 11.0 g and ΔV 10.2 kph with AHR; peak 11.5 g and ΔV 10.7 kph with no head restraint). Cervical canal and foraminal narrowing were computed and average peak values statistically compared (P < 0.05) between whiplash protection system, active head restraint, and no head restraint.
Average peak canal and foramen narrowing could not be statistically differentiated between whiplash protection system, active head restraint, or no head restraint. Peak narrowing with whiplash protection system or active head restraint was 2.7 mm for canal diameter and 1.6 mm, 2.7 mm, and 5.9 mm(2) for foraminal width, height and area, respectively.
While lower cervical spine cord compression during a rear crash is unlikely in those with normal canal diameters, these results demonstrated foraminal kinematics sufficient to compress spinal ganglia and nerve roots. Future anti-whiplash systems designed to reduce cervical neural space narrowing may lead to reduced radicular symptoms in whiplash patients.
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