Cervical vertebral motions and biomechanical responses to direct loading of human head

Ono, Koshiro; Kaneoka, Koji; Hattori, Shinichiro; Ujihashi, Sadayuki; Takhounts, Erik G.; Haffner, Mark; Eppinger, Rolf H.

There is very little known data characterizing the biomechanical responses of the human head and neck under direct head loading conditions. However, the evaluation of the appropriateness of current crash test dummy head/neck systems is easily accomplished. Such an effort, using experimental means, generates and provides characterizations of human head/neck response to several direct head loading conditions. Low-level impact loads were applied to the head and face of volunteers and dummies. The resultant forces and moments at the occipital condyle were calculated. For the volunteers, activation of the neck musculature was determined using EMG. In addition, cervical vertebral motions of the volunteers have been taken by means of x-ray cineradiography. The Ethics Committee of Tsukuba University approved the protocol of the experiments in advance. External force of about 210 N was applied to the head and face of five volunteers with average age of 25 for the duration of 100 ms or so, via a strap at one of four locations in various directions: 1) an upward load applied to the chin, 2) a rearward load applied to the chin without facial mask, 3) a rearward load applied to the chin with the facial mask, and 4) a rearward load applied to the forehead. The same impact force as those for the human volunteers was also applied to HY-III, THOR and BioRID.

It is found that cervical vertebral motions differ markedly according to the difference in impact loading condition. Some particular characteristics are also found, such as the flexion or extension of the upper cervical vertebrae (C0, C1 and C2) or middle cervical vertebrae (C3-C4), showing that the modes of cervical vertebral motions are markedly different among the different loading conditions. It is also found that the biofidelity of dummies to neck response characteristics of the volunteers at the low-level impact loads is in the order of BioRID, THOR and HY-III. It is relevant in this regard that the BioRID dummy was designed for a low-severity impact environment, whereas THOR and HY-III were optimized for higher severity impacts.

Keywords: Dummies; Neck; Biofidelity; Human Body; Cervical Vertebrae

Year

Entry

2001

Haffner M, Eppinger R, Rangarajan N, Shams T, Artis M, Beach D. Foundations and elements of the NHTSA Thor ALPHA ATD design. In: Proceedings of the 17th International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 4-7, 2001; Amsterdam, The Netherlands.

2001

Ono K, Kaneoka K, Sun EA, Takhounts EG, Eppinger RH. Biomechanical response of human cervical spine to direct loading of the head. In: Proceedings of the 2001 International IRCOBI Conference on the Biomechanics of Impact. October 10-12, 2001; Isle of Man, UK.

2000

Deng B, Begeman PC, Yang KH, Tashman S, King AI. Kinematics of human cadaver cervical spine during low speed rear-end impacts. Stapp Car Crash J. 2000;44:171-188. SAE 2000-01-SC13.

1997

Ono K, Kaneoka K, Wittek A, Kajzer J. Cervical injury mechanism based on the analysis of human cervical vertebral motion and head-neck-torso kinematics during low speed rear impacts. In: Proceedings of the 41st Stapp Car Crash Conference. November 13-14, 1997; Lake Buena Vista, FL. Warrendale, PA: Society of Automotive Engineers:339-356. SAE 973340.

1993