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Kinetics of the head-neck complex in low-speed rear impact.
Biomed Sci Instrum. 2003; 39:245-50.BS

Abstract

A comprehensive characterization of the biomechanics of the cervical spine in rear impact will lead to an understanding of the mechanisms of whiplash injury. Cervical kinematics have been experimentally described using human volunteers, full-body cadaver specimens, and isolated and intact head-neck specimens. However, forces and moments at the cervico-thoracic junction have not been clearly delineated. An experimental investigation was performed using ten intact head-neck complexes to delineate the loading at the base of the cervical spine and angular acceleration of the head in whiplash. A pendulum-minisled apparatus was used to simulate whiplash acceleration of the thorax at four impact severities. Lower neck loads were measured using a six-axis load cell attached between the minisled and head-neck specimens, and head angular motion was measured with an angular rate sensor attached to the lateral side of the head. Shear and axial force, extension moment, and head angular acceleration increased with impact severity. Shear force was significantly larger than axial force (p < 0.0001). Shear force reached its maximum value at 46 msec. Maximum extension moment occurred between 7 and 22 msec after maximum shear force. Maximum angular acceleration of the head occurred 2 to 18 msec later. Maximum axial force occurred last (106 msec). All four kinetic components reached maximum values during cervical S-curvature, with maximum shear force and extension moment occurring before the attainment of maximum S-curvature. Results of the present investigation indicate that shear force and extension moment at the cervico-thoracic junction drive the non-physiologic cervical S-curvature responsible for whiplash injury and underscore the importance of understanding cervical kinematics and the underlying kinetics.

Authors+Show Affiliations

Stemper BD
Department of Neurosurgery, Medical College of Wisconsin, V.A. Medical Center, Marquette University, Milwaukee, Wisconsin, USA.
Yoganandan N
No affiliation info available
Pintar FA
No affiliation info available

MeSH

AccelerationAccidents, TrafficCadaverCervical VertebraeElasticityHeadHumansKineticsMotionNeckPhysical StimulationReproducibility of ResultsRotationSensitivity and SpecificityShear StrengthTorqueWeight-BearingWhiplash Injuries

Pub Type(s)

Comparative Study
Journal Article
Research Support, U.S. Gov't, Non-P.H.S.
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

12724902

Citation

Stemper, Brian D., et al. "Kinetics of the Head-neck Complex in Low-speed Rear Impact." Biomedical Sciences Instrumentation, vol. 39, 2003, pp. 245-50.
Stemper BD, Yoganandan N, Pintar FA. Kinetics of the head-neck complex in low-speed rear impact. Biomed Sci Instrum. 2003;39:245-50.
Stemper, B. D., Yoganandan, N., & Pintar, F. A. (2003). Kinetics of the head-neck complex in low-speed rear impact. Biomedical Sciences Instrumentation, 39, 245-50.
Stemper BD, Yoganandan N, Pintar FA. Kinetics of the Head-neck Complex in Low-speed Rear Impact. Biomed Sci Instrum. 2003;39:245-50. PubMed PMID: 12724902.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Kinetics of the head-neck complex in low-speed rear impact. AU - Stemper,Brian D, AU - Yoganandan,Naryan, AU - Pintar,Frank A, PY - 2003/5/3/pubmed PY - 2003/6/18/medline PY - 2003/5/3/entrez SP - 245 EP - 50 JF - Biomedical sciences instrumentation JO - Biomed Sci Instrum VL - 39 N2 - A comprehensive characterization of the biomechanics of the cervical spine in rear impact will lead to an understanding of the mechanisms of whiplash injury. Cervical kinematics have been experimentally described using human volunteers, full-body cadaver specimens, and isolated and intact head-neck specimens. However, forces and moments at the cervico-thoracic junction have not been clearly delineated. An experimental investigation was performed using ten intact head-neck complexes to delineate the loading at the base of the cervical spine and angular acceleration of the head in whiplash. A pendulum-minisled apparatus was used to simulate whiplash acceleration of the thorax at four impact severities. Lower neck loads were measured using a six-axis load cell attached between the minisled and head-neck specimens, and head angular motion was measured with an angular rate sensor attached to the lateral side of the head. Shear and axial force, extension moment, and head angular acceleration increased with impact severity. Shear force was significantly larger than axial force (p < 0.0001). Shear force reached its maximum value at 46 msec. Maximum extension moment occurred between 7 and 22 msec after maximum shear force. Maximum angular acceleration of the head occurred 2 to 18 msec later. Maximum axial force occurred last (106 msec). All four kinetic components reached maximum values during cervical S-curvature, with maximum shear force and extension moment occurring before the attainment of maximum S-curvature. Results of the present investigation indicate that shear force and extension moment at the cervico-thoracic junction drive the non-physiologic cervical S-curvature responsible for whiplash injury and underscore the importance of understanding cervical kinematics and the underlying kinetics. SN - 0067-8856 UR - https://www.unboundmedicine.com/medline/citation/12724902/Kinetics_of_the_head_neck_complex_in_low_speed_rear_impact_ DB - PRIME DP - Unbound Medicine ER -