Development of Lower Neck Injury Assessment Reference Values Based on Comparison of ATD and PMHS Tests

2010 ◽  
Vol 3 (1) ◽  
pp. 308-323
Author(s):  
Christine Raasch ◽  
Michael Carhart ◽  
B. Johan Ivarsson ◽  
Scott Lucas
2020 ◽  
Vol 23 (1) ◽  
Author(s):  
Irving S. Scher ◽  
Lenka L. Stepan ◽  
Ryan W. Hoover

AbstractHead and neck injuries sustained during water skiing and wakeboarding occur as a result of falls in water and collisions with obstacles, equipment, or people. Though water sports helmets are designed to reduce injury likelihood from head impacts with hard objects, some believe that helmets increase head and neck injury rates for falls into water (with no impact to a solid object). The effect of water sports helmets on head kinematics and neck loads during simulated falls into water was evaluated using a custom-made pendulum system with a Hybrid-III anthropometric testing device. Two water entry configurations were evaluated: head-first and pelvis-first water impacts with a water entry speed of 8.8 ± 0.1 m/s. Head and neck injury metrics were compared to injury assessment reference values and the likelihoods of brain injury were determined from head kinematics. Water sport helmets did not increase the likelihood of mild traumatic brain injury compared to a non-helmeted condition for both water entry configurations. Though helmets did increase injury metrics (such as head acceleration, HIC, and cervical spine compression) in some test configurations, the metrics remained below injury assessment reference values and the likelihoods of injury remained below 1%. Using the effective drag coefficients, the lowest water impact speed needed to produce cervical spine injury was estimated to be 15 m/s. The testing does not support the supposition that water sports helmets increase the likelihood of head or neck injury in a typical fall into water during water sports.


2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 639-644
Author(s):  
John Humm ◽  
Narayan Yoganandan

ABSTRACT Introduction Under G +x accelerative loading, the Hybrid III anthropomorphic test device (ATD) is used to advance human safety. Although injury assessment risk curves (IARCs) are available at the level of the occipital condyles (commonly termed as upper neck), they do not exist for the cervical-thoracic junction (lower neck). The objectives of this study are to develop IARCs under G +x impact accelerations for the Hybrid III ATD and test device for human occupant restraint (THOR) ATD at the cervical thoracic junction. Methods A series of Hybrid III ATD tests were conducted using input conditions that matched previously published cadaver tests. A separate series of THOR-ATD tests were conducted using the same input conditions that matched the same previously published cadaver tests. This type of experimental design where the cadaver input condition is the same as the ATD tests are termed matched-pair tests (Cadaver-Hybrid III and Cadaver-THOR-ATD). Injury outcomes from human cadaver tests were used with loads at the cervical thoracic junction, measured in the ATD tests. Data were censored based on injury outcomes and the number of tests conducted on each specimen. Parametric survival analysis was used to derive IARCs for cervical thoracic junction force-, moment-, and interaction-based lower neck injury criterion (LNic). Results Injuries were scored according to the Abbreviated Injury Scale scheme. Abbreviated Injury Scale 1 or 2 was scored as injured. The 50% risk levels for the Hybrid III ATD were 315 N, 70 Nm, and 1.12 for the cervical thoracic A/P shear force-, sagittal plane extension moment-, and LNic-based injury criterion, respectively. Results for the THOR ATD were 261 N, 69 Nm, and 1.51. Conclusions This is the first study to develop cervical thoracic junction IARCs for the ATDs based on force, moment, and LNic for posterior to anterior loading.


2009 ◽  
Author(s):  
M. Philippens ◽  
J. Wismans ◽  
P. A. Forbes ◽  
N. Yoganandan ◽  
F. A. Pintar ◽  
...  

Author(s):  
J Latchford ◽  
E C Chirwa ◽  
T Chen ◽  
M Mao

Car-rear-impact-induced cervical spine injuries present a serious burden on society and, in response, seats offering enhanced protection have been introduced. Seats are evaluated for neck protection performance but only at one specific backrest angle, whereas in the real world this varies greatly owing to the variation in occupant physique. Changing the backrest angle modifies the seat geometry and thereby the nature of its interaction with the occupant. Low-velocity rear-impact tests on a BioRID II anthropomorphic test dummy (ATD) have shown that changes in backrest angle have a significant proportionate effect on dummy kinematics. A close correlation was found between changes in backrest angle and the responses of neck injury predictors such as lower neck loading and lower neck shear but not for the neck injury criterion NICmax. Torso ramping was evident, however, with negligible effect in low-velocity impacts. The backrest angle ranged from 20° to 30° whereas the BioRID II spine was adapted to a range from 20° to 26.5°. Nevertheless, in general, instrumentation outputs correlated well, indicating that this ATD could be used for evaluating seats over a 20–30° range rather than solely at 25° as required by current approval test specifications.


2011 ◽  
Author(s):  
Jeffrey T. Somers ◽  
Bradley Granderson ◽  
John W. Melvin ◽  
Ala Tabiei ◽  
Charles Lawrence ◽  
...  

2017 ◽  
Vol 45 (5) ◽  
pp. 1194-1203 ◽  
Author(s):  
Narayan Yoganandan ◽  
Frank A. Pintar ◽  
Anjishnu Banerjee

Author(s):  
Sajal Chirvi ◽  
Frank A. Pintar ◽  
Narayan Yoganandan

Lower neck injuries inferior to C4 level, such as fractures and dislocations, occur in motor vehicle crashes, sports, and military events. The recently developed interaction criterion, termed Nij, has been used in automotive safety standards and is applicable to the upper neck. Such criterion does not exist for the lower neck. This study was designed to conduct an analysis of data of lower neck injury metrics toward the development of a mechanistically appropriate injury criterion. Axial loads were applied to the crown of the head of post mortem human subject (PMHS) head-neck complexes at different loading rates. The generalized force histories at the inferior end of the head-neck complex were recorded using a load cell and were transformed to the cervical-thoracic joint. Peak force and peak moment (flexion or extension) were quantified for each test from corresponding time histories. Initially, a survival analysis approach was used to derive injury probability curves based on peak force and peak moment alone. Both force and moment were considered as primary variables and age a covariate in the survival analysis. Age was found to be a significant (p<0.05) covariate for the compressive force and flexion moment but insignificant for extension moment (p>0.05). A lower neck Nij formulation was done to derive a combined interactive metric. To derive cadaver-based metrics, critical intercepts were obtained from the 90% injury probability point on peak force and peak moment curves. The PMHS-based critical intercepts derived from this study for compressive force, flexion, and extension moment were 4471 N, 218 Nm, and 120 Nm respectively. The lower cervical spine injury criterion, Lower Nij (LNij), was evaluated in two different formulations: peak LNij and mechanistic peak LNij. Peak LNij was obtained from the LNij time history regardless of when it occurred. Mechanistic peak LNij was obtained from the LNij time history only during the time when the resulting injury mechanism occurred. Injury mechanism categorization included compression-flexion, compression-extension, and those best represented by a more pure compression-related classification. Mechanistic peak LNij was identified based on the peak timing of the injury mechanism. Peak LNij and mechanistic peak LNij were found to be significant (p<0.05) predictors of injury with age as a covariate. The 50% injury probability was 1.38 and 1.13 for peak LNij and mechanistic peak LNij, respectively. These results provide preliminary data based on PMHS tests for establishing lower neck injury criteria that may be used in automotive applications, sports and military research to advance safety systems.


Author(s):  
Liang Hong ◽  
Gang Liu

According to the driver’s moving posture in the frontal collision, the movement process of the driver could be divided into the three stages. At present, the researchers mainly focused on the neck injuries in the first stage of the driver movement, seldom involve the neck injuries in the second and third stage of the driver movement. The aim of this study is to investigate the neck injuries in the three stages comprehensively to expand the protective scope of the neck. Firstly, the simulation model of the driver restraint system was developed and validated. Secondly, parametric studies were conducted to investigate the influences of the design parameters of the driver restraint system on the occurrence times and the variation trends of the upper and lower neck injuries. Finally, the driver restraint system design parameters were optimized globally using the whole injury criterion of the neck WICN. The results indicate that the driver restraint system should be designed with the moderate vent leakage coefficient, inflator mass-flow rate and fabric permeability coefficient of airbag, and the smaller recliner rotational stiffness of seatback for reducing the neck injuries. After optimization, the peak anterior shear force of lower neck F3 reduces by 27.2%, the peak extension bending moment of upper and lower neck Mupper, Mlower decline by 22.4% and 22.2% respectively, WICN decreases by 15.2%, and the other neck injury values also show a declining trend. At the moment, both the peak anterior shear force of lower neck F3 and the peak extension bending moment of lower neck Mlower appear in the second stage, the peak extension bending moment of upper neck Mupper appears in the third stage, the other neck injury values appear in the first stage.


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