Traumatic brain injuries constitute a significant portion of injury resulting from automotive collisions, motorcycle crashes, and sports collisions. Brain not only represent serious trauma for those involved but also place an enormous burden on society, often exacting heavy economical, social, emotional price. Development intervention strategies to prevent or minimize these requires complete understanding mechanisms, response tolerance level. In this study, attempt is made delineate actual...

Low-back pain has a complex and multi-faceted etiology. The articular facets have been shown to be load-bearing structures may site for low-back pain. aim of this paper is establish the mechanism transmission axial load across facet joint propose facet-related hypothesis was studied by two methods. Lumbar segments were instrumented with an intervertebral cell (IVLC) measure disc so that could deduced. applied moved 10 mm anteriorly 12.5 posteriorly from center vertebral body. then separated...

The principal focus of this study was the measurement relative brain motion with respect to skull using a high-speed, biplanar x-ray system and neutral density targets (NDTs). A suspension fixture used for testing inverted, perfused, human cadaver heads. Each specimen subjected multiple tests, either struck at rest 152-mm-diameter padded impactor face, or stopped against an angled surface from steady-state motion. impacts were frontal occipital regions. An array NDTs implanted in...

High-speed biplane x-ray and neutral density targets were used to examine brain displacement deformation during impact. Relative motion, maximum principal strain, shear intracranial pressure measured in thirty-five impacts using eight human cadaver head neck specimens. The effect of a helmet was evaluated. During impact, local tissue tends keep its position shape with respect the inertial frame, resulting relative motion between skull brain. motions tend follow looping patterns. Similar...

Many finite element models have been developed by several research groups in order to achieve a better understanding of brain injury. Due the lack experimental data, validation these has generally limited. Consequently, applying investigate responses also Over last years, versions Wayne State University injury model (WSUBIM) were developed. However, none is capable simulating indirect impacts with an angular acceleration higher than 8,000 rad/s(2). Additionally, density and quality mesh...

This study was conducted to investigate differences in brain response due frontal and lateral impacts based on a partially validated three-dimensional finite element model with all essential anatomical features of human head. Identical impact boundary conditions were used for both the simulations. Intracranial pressure localized shear stress distributions predicted from these analyzed. The higher positive pressures accompanied by relatively large skull deformation at site when compared...

OBJECTIVE: Brain responses from concussive impacts in National Football League football games were simulated by finite element analysis using a detailed anatomic model of the brain and head accelerations laboratory reconstructions game impacts. This study compares with physician determined signs symptoms concussion to investigate tissue-level injury mechanisms. METHODS: The Wayne State University Head Injury Model (Version 2001) was used because it has fine detail cranium more than 300,000...

We have developed a totally new three-dimensional human head model in which the gray matter, white vehicles and parasagittal bridging veins were included. This study is continuation of modeling efforts two-dimensional porcine brain models by Zhou et al. (1994) Ruan (1994). The paper presents some preliminary simulation results for direct frontal impact an indirect sagittal plane rotational ro delineate differences between homogeneous inhomogeneous models, to mechanism subdural hematoma. Language: en

The impact response of the human head has been determined by three-dimensional finite element modeling. This model represents essential features a 50th percentile head. It includes layered shell closely representing cranial bones with interior contents occupied an inviscid continuum to simulate brain. A thin fluid layer was included represent cerebral-spinal fluid. To validate model, its obtained applying sine-squared pulse 6.8 kN in magnitude and 10 ms duration. load applied freely...

The purpose of this study was to characterize somatosensory units the lumbar facet joint, which may play a central role in idiopathic low-back pain. A laminectomy performed on spine adult male New Zealand White rabbits. Receptive fields mechanosensitive afferent were investigated joint and adjacent surrounding tissues, electrophysiological recordings obtained from filaments dorsal root. Twenty-four identified region joint: ten, capsule joint; twelve, border regions between muscle or tendon;...

Although there has been a large number of mathematical models proposed for the simulation spinal response to acceleration, few have validated against experimental data and none appears reflect actual conditions load transmission from one vertebra next. This paper provides brief survey existing presents discrete parameter model with validation. The via articular facets is major new feature model, based on previously obtained data. Good correlation was between results experimentally measured...

Idiopathic low back pain has confounded health care practitioners for decades. The cellular and neural mechanisms that lead to facet pain, discogenic sciatica are not well understood. To help elucidate these mechanisms, anesthetized New Zealand white rabbits were used in a series of neurophysiologic neuroanatomic studies. These studies showed the following evidence support pain: an extensive distribution small nerve fibers endings lumbar joint, nerves containing substance P, high threshold...

The dynamic response of the human head to side impact was studied by 2-dimensional finite element modeling. Three models were formulated in this study. Model I is an axisymmetric model. It simulated closed shell head, and consisted a single-layered spherical filled wiht inviscid fluid. other two (Model II III) are plane strain coronal section head. approximated 50th percentile male outer layer simulate cranial bone interior core intracranial contents. configuration III same as but more...

The purposes of this study were to measure the relative linear and angular displacements each pair adjacent cervical vertebrae compute changes in distance between two facet joint landmarks during low posterior-anterior (+Gx) acceleration without significant hyperextension head. A total twentysix speed rear-end impacts conducted using six postmortem human specimens. Each cadaver was instrumented with three neck targets embedded vertebra nine accelerometers on Sequential x-ray images collected...

Ten male and ten female subjects were tested for their ability to exert maximal force about the lumbo-sacral junction (as is done during lifting) under controlled isometric isokinetic conditions. The myoelectric activity of trunk muscles, intra-abdominal pressure, torque produced by back monitored. There are prominent differences in manner which utilize musculature production statically dynamically. A significant lag was identified between onset pressure torque, this increased with...