• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.2
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• pp.135-142
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• 2007

MADYMO human model with the detail neck was used to investigate the reaction force of neck and neck injury from rear impact directions. In the validation simulation, head acceleration, thorax acceleration and the global kinematics of the head and neck were correlated well with experimental data. Acceleration data from three 15 km/h low speed car rear impact pendulum tests(rear-end, offset, oblique) were used to simulate the model. In the simulation results, the reaction force on the facet joint and discs in the oblique rear impact were higher than rear-end, offset rear impacts. Further research is still needed in order to neck injury analysis about different crash parameters.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.1
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• pp.1-6
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• 2017

Ballistic impact on a soldier wearing a helmet can induce fatal injury, even if the helmet is not penetrated. Although studies on this type of injury have been performed, most of them have used an analytical model focused on head injury only. The injury of the neck muscles and cervical vertebrae by non-penetrating ballistic impact affects the survivability of soldiers, despite not inflicting fatal injury to the human body. Therefore, an analytical model of the head and neck muscles are necessary. In this study, an analysis of human body injury using the previously developed head model, as well as a cervical model with muscles, was performed. For the quantitative prediction of injury, the stress, strain, and HIC were compared. The results from the model including the cervical system indicated a lower extent of injury than the results from the model excluding them. The results of head injury were compared with other references for reliability.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.6 s.237
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• pp.913-920
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• 2005

Compared to previous in-vitro test, FE model showed reliable motion patterns. A finite element model of a 50th percentile male neck was developed to study the mechanics of whiplash injury while the rear impacts. The model was consisted of the whole cervical vertebrae including part of occipital, intervertebral discs. which were modeled using linear viscoelastic materials and posterior elements. The sliding interfaces were defined to simulate contact phenomena in facet joints and in odontoid process. All ligaments and atlanto-occipital membrane were modeled as nonlinear bar elements. Only muscle elements were not considered. Motion of each cervical vertebra was obtained from the dynamic simulation with a MADYMO model for 15 km/h $40\%$ rear end offset impacts. Soft tissue neck injury(STNI) was investigated with a developed FE model. In FE model analysis, the high stress was appeared at C3/C4 disc in offset impact. Further research is still needed in order to improve the developed neck FE model for many different crash patterns.

• Journal of Mechanical Science and Technology
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• v.14 no.3
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• pp.338-349
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• 2000

Neck muscle forces and spinal loads at the C4/5 level were estimated that result from isometric voluntary ramp efforts gradually developing to maximums in flexion, extension, left lateral bending and right lateral bending. Electromyographic (EMG) activities, a three-dimensional anatomic data of the neck and a hybrid model, EMG-assisted optimization (EMGAO) model, were used. The model computed the cervical loads at 25%,50%,75%, and 100% of peak moments. The highest model-predicted C4/5 joint compressive forces occurred during flexion; $361\;({\pm}164)\;N,\;811\;({\pm}288)\;N,\;1207\;({\pm}491)\;N\;and\;1674\;({\pm}319)\;N$ in 25%, 50%, 75% and 100% of peak moment respectively. Variations in load distribution among the agonistic muscles and co-contractions of antagonistic muscles were estimated during ramp efforts. Results suggest that higher C4/5 joint loads than previously reported are possible during isometric, voluntary muscle contractions. These higher physiological loads at C4/5 level must be considered possible during orthopedic reconstruction at this level.

• Journal of Biomedical Engineering Research
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• v.16 no.4
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• pp.491-498
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• 1995

A numerical human head/neck model was constructed for analyzing the implication in decleration injuries. This model consists of nine rigid bodies representing the head, cervical vertebrae C1-C7, and T1. These rigid bodies were connected by intervertebral disks described by massless beam elements. Muscles and ligaments were also incoperated in the model represented by nonlinear spring and viscoblastic element respectively Agreement of the analytical kinematic response with the results of experimental data from a volunteer run was satisfactory. Moreover, possible injury estimation from the calculated moment, force variations in the disc, and force variation in ligaments matched well with clinical observations.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.1
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• pp.132-139
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• 2005

The driving position of head restraints and the relative risk of neck injury were studied in the computer simulation. MADYMO human model with the detail neck model was used to define the magnitude and direction of internal forces acting on the cervical spine during rear-end impact and to determine the effect of the initial position of the occupant's head with respect to the head restraints. Maximum reaction forces were generated during the head contact to the restraint and relatively large forces were generated at each spinal components in lower cervical spine in proportion to backset and height distance increasement.

• International Journal of Automotive Technology
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• v.5 no.1
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• pp.33-46
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• 2004

A finite element model development of a 50th percentile male cervical spine is presented in this paper. The model consists of rigid, geometrically accurate vertebrae held together with deformable intervertibral disks, facet joints, and ligaments modeled as a series of nonlinear springs. These deformable structures were rigorously tuned, through failure, to mimic existing experimental data; first as functional unit characterizations at three cervical levels and then as a fully assembled c-spine using the experimental data from Duke University and other data in the NHTSA database. After obtaining satisfactory validation of the performance of the assembled ligamentous cervical spine against available experimental data, 22 cervical muscle pairs, representing the majority of the neck's musculature, were added to the model. Hill's muscle model was utilized to generate muscle forces within the assembled cervical model. The muscle activation level was assumed to be the same for all modeled muscles and the degree of activation was set to correctly predict available human volunteer experimental data from NBDL. The validated model is intended for use as a post processor of dummy measurement within the simulated injury monitor (SIMon) concept being developed by NHTSA where measured kinematics and kinetic data obtained from a dummy during a crash test will serve as the boundary conditions to "drive" the finite element model of the neck. The post-processor will then interrogate the model to determine whether any ligament have exceeded its known failure limit. The model will allow a direct assessment of potential injury, its degree and location thus eliminating the need for global correlates such as Nij.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.2
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• pp.139-143
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• 2010

Whiplash injuries often occur in motor vehicle collision accidents. This injury frequently occurs in the cervical region. However, the reason for this has not yet been clarified. In this study, a multi-body neck model with muscles was designed. Some muscles in the model were preloaded; these were previously determined using the concept of the follower load. Cervical spinal vertebrae, discs, and muscles were designed in accordance with the human cervical spine. The purpose of this study was to investigate the effect of preloads on muscles. The results imply that the whiplash model with preloaded muscles simulates practical situations more closely than models without preloads.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.6
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• pp.251-258
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• 2018

Recently, due to the increase in the traffic volume of vehicle, the collision of the vehicle collision has been increased so that the neck injuries of the passengers has been increased. In order to prevent this, vehicle collision analysis research using computer simulation has been actively carried out in consideration of the design point of car seat. In this study, I used the MADYMO program for analyzing the passenger behavior using a BioRID II dummy, and predicted the neck injuries of passengers according to the change of the backset at the rearward collision of the driving speed of 16km/h. As a result, it was found that the shorter the backset, the shorter the contact start time but the contact completion time was almost the same and the T1 acceleration showed that the acceleration increased with the backset. In addition, the tensile strength increases as the backset increases, and NIC (Neck Injury Criterion) increases as the head speed reaches the headrest.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.7
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• pp.956-961
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• 2014

Due to the increasing needs of anti-fall device for elderly, it is required to develop the test rigs for fall simulation. The femoral bone model consists of silicone and steel is used as an effective device to simulate falls. In this work, we propose five different femoral bone models and analyse them by using a commercial FEA tool. It has been shown that two kinds of simplified models exhibit the simulated side falls with an error range of ~1% in the impact load of femoral neck compared with full model. Especially, the upper tissue model is found to provide us with the best efficient test environment, attributable to its simple structure.