Kinetics of the head-neck complex in low-speed rear impact. Biomed Sci Instrum 2003;39:245-50
Date
05/03/2003Pubmed ID
12724902Scopus ID
2-s2.0-0037258981 (requires institutional sign-in at Scopus site) 11 CitationsAbstract
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.
Author List
Stemper BD, Yoganandan N, Pintar FAAuthors
Frank A. Pintar PhD Chair, Professor in the Biomedical Engineering department at Medical College of WisconsinBrian Stemper PhD Professor in the Biomedical Engineering department at Medical College of Wisconsin
Narayan Yoganandan PhD Professor in the Neurosurgery department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AccelerationAccidents, Traffic
Cadaver
Cervical Vertebrae
Elasticity
Head
Humans
Kinetics
Motion
Neck
Physical Stimulation
Reproducibility of Results
Rotation
Sensitivity and Specificity
Shear Strength
Torque
Weight-Bearing
Whiplash Injuries
