Biomechanical response of head/neck/torso and cervical vertebral motion to lateral impact loading on the shoulders of volunteers

Ono, Koshiro; Ejima, Susumu; Kaneoka, Koji; Fukushima, Makoto; Yamada, Shintaro; Ujihashi, Sadayuki

To understand the response of the head, neck and torso during a lateral collision, and to investigate the relation between cervical vertebral motion and the occurrence of neck injuries, lateral impact experiments were conducted on the shoulder areas of human volunteers. Test subjects consisted of 8 volunteers (5 males and 3 females). For the analysis of cervical vertebral motions of each subject, a cineradiography system was used. A VICON motion photographic device was also used for the three-dimensional analysis of head/neck/torso motions. In the experiment, 3 levels of impact force (400N, 500N, and 600N) were applied considering both the presence and absence of muscle tension.

Cervical vertebral rotations all started at 35 ms, but the time required to reach the peak rotation increased toward the upper vertebrae, with C7 and T1 peaking at 120 ms and the final peak in the head at 120 ms. At around 35-80 ms, the rotation angle of C5 surpassed those of the head and C4 showing that the cervical spine was bending into an S-curve. This phenomenon shows the same type of cervical vertebral motions causing whiplash during a rear-end collision. Also, extreme compression was at work in the vertebral disc and/or the facet joint in C6/C7 and C7/T1, suggesting a high probability of injury occurring in the neck.

Year

Entry

2004

Compigne S, Caire Y, Quesnel T, Verries J-P. Non-injurious and injurious impact response of the human shoulder three-dimensional analysis of kinematics and determination of injury threshold. Stapp Car Crash J. 2004;48:89-123. SAE 2004-22-0005.

2002

Krafft M, Kullgren A, Ydenius A, Tingvall C. Influence of crash pulse characteristics on whiplash associated disorders in rear impacts: crash recording in real life crashes. Traffic Inj Prev. 2002;3(2):141-149.

2002

Compigne S, Caire Y, Verriest JP. Three dimensional dynamic response of the human shoulder submitted to lateral and oblique glenohumeral joint impacts. In: Proceedings of the 2002 International IRCOBI Conference on the Biomechanics of Impact. September 18-20, 2002; Munich, Germany.

2003

Compigne S, Caire Y, Quesnel T, Verries J-P. Lateral and oblique impact loading of the human shoulder 3D acceleration and force-deflection data. In: Proceedings of the 2003 International IRCOBI Conference on the Biomechanics of Impact. September 25, 2003; Lisbon, Portugal.265-279.

2001

Yoganandan N, Kumaresan S, Pintar FA. Biomechanics of the cervical spine, II: cervical spine soft tissue responses and biomechanical modeling. Clin Biomech (Bristol, Avon). January 2001;16(1):1-27.