Human Neck Finite Element Model Development and Validation against Original Experimental Data

Thoughts and perspectives on biomechanical numerical models under impacts: Are women forgotten from research?

The present paper explores a series of articles in the literature which deal with impact biomechanics of the head and thorax/abdomen segments, investigating the "sex specific properties/data" used in the studies. Statements in these studies are analyzed and point out, the use of male or female subjects for the developments of finite element models and their validation against experimental data. The present analysis raises the question about "androcentrism," and how biomechanical engineering findings and the design of the derived protecting devices are focused on male subjects.

Investigation of anteroposterior head-neck responses during severe frontal impacts using a brain-spinal cord complex FE model

Injuries of the human brain and spinal cord associated with the central nervous system (CNS) are seen in automotive accidents. CNS injuries are generally categorized into severe injuries (AIS 3+). However, it is not clear how the restraint conditions affect the CNS injuries. This paper presents a newly developed three-dimensional (3D) finite element head-neck model in order to investigate the biomechanical responses of the brain-spinal cord complex. The head model consists of the scalp, skull, and a detailed description of the brain including the cerebrum, cerebellum, brainstem with distinct white and gray matter, cerebral spinal fluid (CSF), sagittal sinus, dura, pia, arachnoid, meninx, falx cerebri, and tentorium. Additionally, the neck model consists of the cervical vertebral bodies, intervertebral discs, muscles, ligaments, spinal cord with white and gray matter, cervical pia, and CSF. The two models were linked together to construct a finite element (FE) model of the brain-spinal cord complex. The material stiffness and failure properties of porcine cervical pia mater were measured from uniaxial tensile tests with various strain rates at Yamaguchi University. The head-neck model was validated against three sets of brain test data obtained by Nahum et al. (1977), Trosseille et al. (1992), and Hardy et al. (2001) and two sets of neck test data obtained from Thunnissen et al. (1995) and Pintar et al. (1995). Additionally, a series of parametric studies were conducted to investigate the effects of restraint conditions on CNS injuries. The injury criteria for brain injuries were based on Cumulative Strain Damage Measure, while those for spinal cord injuries were based on the ultimate strains of the spinal cord and pia mater. It was found that the brain-spinal cord model was useful to investigate the relationship between the restraint conditions and CNS injuries.

Development of numerical models for injury biomechanics research: a review of 50 years of publications in the Stapp Car Crash Conference

Numerical analyses frequently accompany experimental investigations that study injury biomechanics and improvements in automotive safety. Limited by computational speed, earlier mathematical models tended to simplify the system under study so that a set of differential equations could be written and solved. Advances in computing technology and analysis software have enabled the development of many sophisticated models that have the potential to provide a more comprehensive understanding of human impact response, injury mechanisms, and tolerance. In this article, 50 years of publications on numerical modeling published in the Stapp Car Crash Conference Proceedings and Journal were reviewed. These models were based on: (a) author-developed equations and software, (b) public and commercially available programs to solve rigid body dynamic models (such as MVMA2D, CAL3D or ATB, and MADYMO), and (c) finite element models. A clear trend that can be observed is the increasing use of the finite element method for model development. A review of these modeling papers clearly indicates the progression of the state-of-the-art in computational methods and technologies in injury biomechanics.