Pub Date : 2024-07-01DOI: 10.1016/j.cjtee.2024.03.002
Yong Han , Hao Yang , He Wu , Di Pan , Bing-Yu Wang
Purpose
The current study aimed to assess the protective performance of helmets equipped with multi-directional impact protection system (MIPS) under various oblique impact loads.
Methods
Initially, a finite element model of a bicycle helmet with MIPS was developed based on the scanned geometric parameters of an actual bicycle helmet. Subsequently, the validity of model was confirmed using the KASK WG11 oblique impact test method. Three different impact angles (30°, 45°, and 60°) and 2 varying impact speeds (5 m/s and 8 m/s) were employed in oblique tests to evaluate protective performance of MIPS in helmets, focusing on injury assessment parameters such as peak linear acceleration (PLA) and peak angular acceleration (PAA) of the head.
Results
The results demonstrated that in all impact simulations, both assessment parameters were lower during impact for helmets equipped with MIPS compared to those without. The PAA was consistently lower in the MIPS helmet group, whereas the difference in PLA was not significant in the no-MIPS helmet group. For instance, at an impact velocity of 8 m/s and a 30° inclined anvil, the MIPS helmet group exhibited a PAA of 3225 rad/s2 and a PLA of 281 g. In contrast, the no-MIPS helmet group displayed a PAA of 8243 rad/s2 and a PLA of 292 g. Generally, both PAA and PLA parameters decreased with the increase of anvil angles. At a 60° anvil angles, PAA and PLA values were 664 rad/s2 and 20.7 g, respectively, reaching their minimum.
Conclusion
The findings indicated that helmets incorporating MIPS offer enhanced protection against various oblique impact loads. When assessing helmets for oblique impacts, the utilization of larger angle anvils and rear impacts might not adequately evaluate protective performance during an impact event. These findings will guide advancements in helmet design and the refinement of oblique impact test protocols.
{"title":"Quantitative analysis of the protective performance of bicycle helmet with multi-direction impact protection system in oblique impact tests","authors":"Yong Han , Hao Yang , He Wu , Di Pan , Bing-Yu Wang","doi":"10.1016/j.cjtee.2024.03.002","DOIUrl":"10.1016/j.cjtee.2024.03.002","url":null,"abstract":"<div><h3>Purpose</h3><p>The current study aimed to assess the protective performance of helmets equipped with multi-directional impact protection system (MIPS) under various oblique impact loads.</p></div><div><h3>Methods</h3><p>Initially, a finite element model of a bicycle helmet with MIPS was developed based on the scanned geometric parameters of an actual bicycle helmet. Subsequently, the validity of model was confirmed using the KASK WG11 oblique impact test method. Three different impact angles (30°, 45°, and 60°) and 2 varying impact speeds (5 m/s and 8 m/s) were employed in oblique tests to evaluate protective performance of MIPS in helmets, focusing on injury assessment parameters such as peak linear acceleration (PLA) and peak angular acceleration (PAA) of the head.</p></div><div><h3>Results</h3><p>The results demonstrated that in all impact simulations, both assessment parameters were lower during impact for helmets equipped with MIPS compared to those without. The PAA was consistently lower in the MIPS helmet group, whereas the difference in PLA was not significant in the no-MIPS helmet group. For instance, at an impact velocity of 8 m/s and a 30° inclined anvil, the MIPS helmet group exhibited a PAA of 3225 rad/s<sup>2</sup> and a PLA of 281 g. In contrast, the no-MIPS helmet group displayed a PAA of 8243 rad/s<sup>2</sup> and a PLA of 292 g. Generally, both PAA and PLA parameters decreased with the increase of anvil angles. At a 60° anvil angles, PAA and PLA values were 664 rad/s<sup>2</sup> and 20.7 g, respectively, reaching their minimum.</p></div><div><h3>Conclusion</h3><p>The findings indicated that helmets incorporating MIPS offer enhanced protection against various oblique impact loads. When assessing helmets for oblique impacts, the utilization of larger angle anvils and rear impacts might not adequately evaluate protective performance during an impact event. These findings will guide advancements in helmet design and the refinement of oblique impact test protocols.</p></div>","PeriodicalId":51555,"journal":{"name":"Chinese Journal of Traumatology","volume":"27 4","pages":"Pages 226-234"},"PeriodicalIF":1.8,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1008127524000282/pdfft?md5=787d8b5b461bf00e07af81ce12571e1b&pid=1-s2.0-S1008127524000282-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140137524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1016/j.cjtee.2024.04.006
Kang Lei , Chen-Zhu Zhao , Fan Li , Shu-Lin Liu , Peng Yang
Purpose
The present study aimed to analyze the influence of muscle activation on lumbar injury under a specific +Gz load.
Methods
A hybrid finite element human body model with detailed lumbar anatomy and lumbar muscle activation capabilities was developed. Using the specific +Gz loading acceleration as input, the kinematic and biomechanical responses of the occupant's lower back were studied for both activated and deactivated states of the lumbar muscles.
Results
The results indicated that activating the major lumbar muscles enhanced the stability of the occupant's torso, which delayed the contact between the occupant's head and the headrest. Lumbar muscle activation led to higher strain and stress output in the lumbar spine under +Gz load, such as the maximum Von Mises stress of the vertebrae and intervertebral discs increased by 177.9% and 161.8%, respectively, and the damage response index increased by 84.5%.
Conclusion
In both simulations, the occupant's risk of lumbar injury does not exceed 10% probability. Therefore, the activation of muscles could provide good protection for maintaining the lumbar spine and reduce the effect of acceleration in vehicle travel direction.
{"title":"Influence of muscle activation on lumbar injury under a specific +Gz load","authors":"Kang Lei , Chen-Zhu Zhao , Fan Li , Shu-Lin Liu , Peng Yang","doi":"10.1016/j.cjtee.2024.04.006","DOIUrl":"10.1016/j.cjtee.2024.04.006","url":null,"abstract":"<div><h3>Purpose</h3><p>The present study aimed to analyze the influence of muscle activation on lumbar injury under a specific +Gz load.</p></div><div><h3>Methods</h3><p>A hybrid finite element human body model with detailed lumbar anatomy and lumbar muscle activation capabilities was developed. Using the specific +Gz loading acceleration as input, the kinematic and biomechanical responses of the occupant's lower back were studied for both activated and deactivated states of the lumbar muscles.</p></div><div><h3>Results</h3><p>The results indicated that activating the major lumbar muscles enhanced the stability of the occupant's torso, which delayed the contact between the occupant's head and the headrest. Lumbar muscle activation led to higher strain and stress output in the lumbar spine under +Gz load, such as the maximum Von Mises stress of the vertebrae and intervertebral discs increased by 177.9% and 161.8%, respectively, and the damage response index increased by 84.5%.</p></div><div><h3>Conclusion</h3><p>In both simulations, the occupant's risk of lumbar injury does not exceed 10% probability. Therefore, the activation of muscles could provide good protection for maintaining the lumbar spine and reduce the effect of acceleration in vehicle travel direction.</p></div>","PeriodicalId":51555,"journal":{"name":"Chinese Journal of Traumatology","volume":"27 4","pages":"Pages 218-225"},"PeriodicalIF":1.8,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1008127524000579/pdfft?md5=45ec2c3eabcb06166fbfc383a95e3f3c&pid=1-s2.0-S1008127524000579-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140923796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1016/j.cjtee.2024.02.005
Di-Yi Liu , Sen Xiao , Fei-Fei Han , Bo-Tao Hu
Purpose
With the increasing level of automation in automobiles, the advent of autonomous vehicles has reduced the tendency of drivers and passengers to focus on the task of driving. The increasing automation in automobiles reduced the drivers' and passengers' focus on driving, which allowed occupants to choose a more relaxed and comfortable sitting position. Meanwhile, the occupant's sitting position went from a frontal, upright position to a more relaxed and reclined one, which resulted in the existing restraint systems cannot to keep occupants safe and secure. This study aimed to determine the effects of different reclining states on occupants' lumbar and neck injuries.
Methods
This is an original research on the field of automotive safety engineering. Occupants in different initial sitting positions (25°, 35°, 45°, and 55°) were adapted to changes in seat back angle and restraint systems and placed in the same frontal impact environment. Neck injury indexes, lumbar axial compression force and acceleration, as well as occupant dynamic response during the impact, were compared in different sitting positions. The injury response and kinematic characteristics of occupants in different reclining positions were analyzed by the control variable method.
Results
As the sitting angle increased, the occupant's head acceleration decreased, and the forward-lean angle decreased. Occupants in the standard sitting position had the greatest neck injury, with an Nij of 0.95, and were susceptible to abbreviated injury scale 2+ cervical medullary injuries. As the seatback angle increased, the geometric position of the lumbar spine tended to be horizontal, and the impact load transmitted greater forces to the lumbar spine. The occupant's lumbar injury was greatest in the lying position, with a peak axial compression force on the lumbar region of 5.5 KN, which was 2.3 KN greater than in the standard sitting position.
Conclusion
The study of occupant lumbar and neck injuries based on different recline states can provide a theoretical basis for optimizing lumbar evaluation indexes, which is conducive to the understanding of the lumbar injury mechanism and the comprehensive consideration of occupant safety protection.
{"title":"Lumbar and neck injuries of occupants in different reclining postures","authors":"Di-Yi Liu , Sen Xiao , Fei-Fei Han , Bo-Tao Hu","doi":"10.1016/j.cjtee.2024.02.005","DOIUrl":"10.1016/j.cjtee.2024.02.005","url":null,"abstract":"<div><h3>Purpose</h3><p>With the increasing level of automation in automobiles, the advent of autonomous vehicles has reduced the tendency of drivers and passengers to focus on the task of driving. The increasing automation in automobiles reduced the drivers' and passengers' focus on driving, which allowed occupants to choose a more relaxed and comfortable sitting position. Meanwhile, the occupant's sitting position went from a frontal, upright position to a more relaxed and reclined one, which resulted in the existing restraint systems cannot to keep occupants safe and secure. This study aimed to determine the effects of different reclining states on occupants' lumbar and neck injuries.</p></div><div><h3>Methods</h3><p>This is an original research on the field of automotive safety engineering. Occupants in different initial sitting positions (25°, 35°, 45°, and 55°) were adapted to changes in seat back angle and restraint systems and placed in the same frontal impact environment. Neck injury indexes, lumbar axial compression force and acceleration, as well as occupant dynamic response during the impact, were compared in different sitting positions. The injury response and kinematic characteristics of occupants in different reclining positions were analyzed by the control variable method.</p></div><div><h3>Results</h3><p>As the sitting angle increased, the occupant's head acceleration decreased, and the forward-lean angle decreased. Occupants in the standard sitting position had the greatest neck injury, with an N<sub>ij</sub> of 0.95, and were susceptible to abbreviated injury scale 2+ cervical medullary injuries. As the seatback angle increased, the geometric position of the lumbar spine tended to be horizontal, and the impact load transmitted greater forces to the lumbar spine. The occupant's lumbar injury was greatest in the lying position, with a peak axial compression force on the lumbar region of 5.5 KN, which was 2.3 KN greater than in the standard sitting position.</p></div><div><h3>Conclusion</h3><p>The study of occupant lumbar and neck injuries based on different recline states can provide a theoretical basis for optimizing lumbar evaluation indexes, which is conducive to the understanding of the lumbar injury mechanism and the comprehensive consideration of occupant safety protection.</p></div>","PeriodicalId":51555,"journal":{"name":"Chinese Journal of Traumatology","volume":"27 4","pages":"Pages 211-217"},"PeriodicalIF":1.8,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1008127524000117/pdfft?md5=b06d2ad1db8ebab03d53ed34866b916e&pid=1-s2.0-S1008127524000117-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140050972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1016/j.cjtee.2024.04.005
Zhi Fu , Yi Chang , Tao Xiong , Wen-Kai Gao , Kui Li , Yu Liu
Purpose
Head injury criterion (HIC) companied by a rotation-based metric was widely believed to be helpful for head injury prediction in road traffic accidents. Recently, the Euro-New Car Assessment Program utilized a newly developed metric called diffuse axonal multi-axis general evaluation (DAMAGE) to explain test device for human occupant restraint (THOR) head injury, which demonstrated excellent ability in capturing concussions and diffuse axonal injuries. However, there is still a lack of comprehensive understanding regarding the effectiveness of using DAMAGE for Hybrid Ⅲ 50th percentile male dummy (H50th) head injury assessment. The objective of this study is to determine whether the DAMAGE could capture the risk of H50th brain injury during small overlap barrier tests.
Methods
To achieve this objective, a total of 24 vehicle crash loading curves were collected as input data for the multi-body simulation. Two commercially available mathematical dynamic models, namely H50th and THOR, were utilized to investigate the differences in head injury response. Subsequently, a decision method known as simple additive weighting was employed to establish a comprehensive brain injury metric by incorporating the weighted HIC and either DAMAGE or brain injury criterion. Furthermore, 35 sets of vehicle crash test data were used to analyze these brain injury metrics.
Results
The rotational displacement of the THOR head is significantly greater than that of the H50th head. The maximum linear and rotational head accelerations experienced by H50th and THOR models were (544.6 ± 341.7) m/s2, (2468.2 ± 1309.4) rad/s2 and (715.2 ± 332.8) m/s2, (3778.7 ± 1660.6) rad/s2, respectively. Under the same loading condition during small overlap barrier (SOB) tests, THOR exhibits a higher risk of head injury compared to the H50th model. It was observed that the overall head injury response during the small overlap left test condition is greater than that during the small overlap right test. Additionally, an equation was formulated to establish the necessary relationship between the DAMAGE values of THOR and H50th.
Conclusion
If H50th rather than THOR is employed as an evaluation tool in SOB crash tests, newly designed vehicles are more likely to achieve superior performance scores. According to the current injury curve for DAMAGE and brain injury criterion, it is highly recommended that HIC along with DAMAGE was prioritized for brain injury assessment in SOB tests.
{"title":"A study on the application of diffuse axonal multi-axis general evaluation for brain injury assessment in small overlap barrier crash test","authors":"Zhi Fu , Yi Chang , Tao Xiong , Wen-Kai Gao , Kui Li , Yu Liu","doi":"10.1016/j.cjtee.2024.04.005","DOIUrl":"10.1016/j.cjtee.2024.04.005","url":null,"abstract":"<div><h3>Purpose</h3><p>Head injury criterion (HIC) companied by a rotation-based metric was widely believed to be helpful for head injury prediction in road traffic accidents. Recently, the Euro-New Car Assessment Program utilized a newly developed metric called diffuse axonal multi-axis general evaluation (DAMAGE) to explain test device for human occupant restraint (THOR) head injury, which demonstrated excellent ability in capturing concussions and diffuse axonal injuries. However, there is still a lack of comprehensive understanding regarding the effectiveness of using DAMAGE for Hybrid Ⅲ 50th percentile male dummy (H50th) head injury assessment. The objective of this study is to determine whether the DAMAGE could capture the risk of H50th brain injury during small overlap barrier tests.</p></div><div><h3>Methods</h3><p>To achieve this objective, a total of 24 vehicle crash loading curves were collected as input data for the multi-body simulation. Two commercially available mathematical dynamic models, namely H50th and THOR, were utilized to investigate the differences in head injury response. Subsequently, a decision method known as simple additive weighting was employed to establish a comprehensive brain injury metric by incorporating the weighted HIC and either DAMAGE or brain injury criterion. Furthermore, 35 sets of vehicle crash test data were used to analyze these brain injury metrics.</p></div><div><h3>Results</h3><p>The rotational displacement of the THOR head is significantly greater than that of the H50th head. The maximum linear and rotational head accelerations experienced by H50th and THOR models were (544.6 ± 341.7) m/s<sup>2</sup>, (2468.2 ± 1309.4) rad/s<sup>2</sup> and (715.2 ± 332.8) m/s<sup>2</sup>, (3778.7 ± 1660.6) rad/s<sup>2</sup>, respectively. Under the same loading condition during small overlap barrier (SOB) tests, THOR exhibits a higher risk of head injury compared to the H50th model. It was observed that the overall head injury response during the small overlap left test condition is greater than that during the small overlap right test. Additionally, an equation was formulated to establish the necessary relationship between the DAMAGE values of THOR and H50th.</p></div><div><h3>Conclusion</h3><p>If H50th rather than THOR is employed as an evaluation tool in SOB crash tests, newly designed vehicles are more likely to achieve superior performance scores. According to the current injury curve for DAMAGE and brain injury criterion, it is highly recommended that HIC along with DAMAGE was prioritized for brain injury assessment in SOB tests.</p></div>","PeriodicalId":51555,"journal":{"name":"Chinese Journal of Traumatology","volume":"27 4","pages":"Pages 200-210"},"PeriodicalIF":1.8,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1008127524000567/pdfft?md5=b4bde7a09029508e141e4f70f8e1e473&pid=1-s2.0-S1008127524000567-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141064557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1016/j.cjtee.2024.03.010
Jin-Ming Wang , Zheng-Dong Li , Chang-Sheng Cai , Ying Fan , Xin-Biao Liao , Fu Zhang , Jian-Hua Zhang , Dong-Hua Zou
Purpose
The toughest challenge in pedestrian traffic accident identification lies in ascertaining injury manners. This study aimed to systematically simulate and parameterize 3 types of craniocerebral injury including impact injury, fall injury, and run-over injury, to compare the injury response outcomes of different injury manners.
Methods
Based on the total human model for safety (THUMS) and its enhanced human model THUMS-hollow structures, a total of 84 simulations with 3 injury manners, different loading directions, and loading velocities were conducted. Von Mises stress, intracranial pressure, maximum principal strain, cumulative strain damage measure, shear stress, and cranial strain were employed to analyze the injury response of all areas of the brain. To examine the association between injury conditions and injury consequences, correlation analysis, principal component analysis, linear regression, and stepwise linear regression were utilized.
Results
There is a significant correlation observed between each criterion of skull and brain injury (p < 0.01 in all Pearson correlation analysis results). A 2-phase increase of cranio-cerebral stress and strain as impact speed increases. In high-speed impact (> 40 km/h), the Von Mises stress on the skull was with a high possibility exceed the threshold for skull fracture (100 MPa). When falling and making temporal and occipital contact with the ground, the opposite side of the impacted area experiences higher frequency stress concentration than contact at other conditions. Run-over injuries tend to have a more comprehensive craniocerebral injury, with greater overall deformation due to more adequate kinetic energy conduction. The mean value of maximum principal strain of brain and Von Mises stress of cranium at run-over condition are 1.39 and 403.8 MPa, while they were 1.31, 94.11 MPa and 0.64, 120.5 MPa for the impact and fall conditions, respectively. The impact velocity also plays a significant role in craniocerebral injury in impact and fall loading conditions (the p of all F-test < 0.05). A regression equation of the craniocerebral injury manners in pedestrian accidents was established.
Conclusion
The study distinguished the craniocerebral injuries caused in different manners, elucidated the biomechanical mechanisms of craniocerebral injury, and provided a biomechanical foundation for the identification of craniocerebral injury in legal contexts.
目的 行人交通事故鉴定的最大挑战在于确定伤害方式。方法基于全人类安全模型（THUMS）及其增强型人体模型 THUMS-空心结构，对 3 种伤害方式、不同加载方向和加载速度进行了 84 次模拟。采用 Von Mises 应力、颅内压、最大主应变、累积应变损伤度量、剪切应力和颅骨应变来分析大脑所有区域的损伤响应。为了研究损伤条件与损伤后果之间的关联，采用了相关分析、主成分分析、线性回归和逐步线性回归等方法。结果观察到颅骨的各项标准与脑损伤之间存在显著的相关性（所有皮尔逊相关分析结果的 p 均为 0.01）。随着撞击速度的增加，颅脑应力和应变呈两阶段增加。在高速撞击（> 40 km/h）中，颅骨上的 Von Mises 应力极有可能超过颅骨骨折的临界值（100 MPa）。摔倒时，颞部和枕部与地面接触，与其他情况下的接触相比，撞击区域的另一侧经历更高频率的应力集中。碾压伤往往会造成更全面的颅脑损伤，由于动能传导更充分，整体变形更大。碾压状态下脑部最大主应变和颅骨 Von Mises 应力的平均值分别为 1.39 和 403.8 兆帕，而撞击和坠落状态下脑部最大主应变和颅骨 Von Mises 应力的平均值分别为 1.31、94.11 兆帕和 0.64、120.5 兆帕。冲击速度在冲击和跌倒加载条件下对颅脑损伤也有显著影响（所有 F 检验的 p 均为 0.05）。结论 该研究区分了不同方式造成的颅脑损伤，阐明了颅脑损伤的生物力学机制，为法律背景下的颅脑损伤鉴定提供了生物力学基础。
{"title":"Parametric analysis of craniocerebral injury mechanism in pedestrian traffic accidents based on finite element methods","authors":"Jin-Ming Wang , Zheng-Dong Li , Chang-Sheng Cai , Ying Fan , Xin-Biao Liao , Fu Zhang , Jian-Hua Zhang , Dong-Hua Zou","doi":"10.1016/j.cjtee.2024.03.010","DOIUrl":"10.1016/j.cjtee.2024.03.010","url":null,"abstract":"<div><h3>Purpose</h3><p>The toughest challenge in pedestrian traffic accident identification lies in ascertaining injury manners. This study aimed to systematically simulate and parameterize 3 types of craniocerebral injury including impact injury, fall injury, and run-over injury, to compare the injury response outcomes of different injury manners.</p></div><div><h3>Methods</h3><p>Based on the total human model for safety (THUMS) and its enhanced human model THUMS-hollow structures, a total of 84 simulations with 3 injury manners, different loading directions, and loading velocities were conducted. Von Mises stress, intracranial pressure, maximum principal strain, cumulative strain damage measure, shear stress, and cranial strain were employed to analyze the injury response of all areas of the brain. To examine the association between injury conditions and injury consequences, correlation analysis, principal component analysis, linear regression, and stepwise linear regression were utilized.</p></div><div><h3>Results</h3><p>There is a significant correlation observed between each criterion of skull and brain injury (<em>p</em> < 0.01 in all Pearson correlation analysis results). A 2-phase increase of cranio-cerebral stress and strain as impact speed increases. In high-speed impact (> 40 km/h), the Von Mises stress on the skull was with a high possibility exceed the threshold for skull fracture (100 MPa). When falling and making temporal and occipital contact with the ground, the opposite side of the impacted area experiences higher frequency stress concentration than contact at other conditions. Run-over injuries tend to have a more comprehensive craniocerebral injury, with greater overall deformation due to more adequate kinetic energy conduction. The mean value of maximum principal strain of brain and Von Mises stress of cranium at run-over condition are 1.39 and 403.8 MPa, while they were 1.31, 94.11 MPa and 0.64, 120.5 MPa for the impact and fall conditions, respectively. The impact velocity also plays a significant role in craniocerebral injury in impact and fall loading conditions (the <em>p</em> of all <em>F</em>-test < 0.05). A regression equation of the craniocerebral injury manners in pedestrian accidents was established.</p></div><div><h3>Conclusion</h3><p>The study distinguished the craniocerebral injuries caused in different manners, elucidated the biomechanical mechanisms of craniocerebral injury, and provided a biomechanical foundation for the identification of craniocerebral injury in legal contexts.</p></div>","PeriodicalId":51555,"journal":{"name":"Chinese Journal of Traumatology","volume":"27 4","pages":"Pages 187-199"},"PeriodicalIF":1.8,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1008127524000373/pdfft?md5=309100d796ac1ba84d8ff60342705222&pid=1-s2.0-S1008127524000373-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140407941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1016/j.cjtee.2024.02.002
Teng-Fei Tian , Fu-Hao Mo , Hao-Yang Su , Can Huang , Hui Zhao , Jun Liu , Bo Shang , Kui Li , Jin-Long Qiu
Purpose
Under-foot impact loadings can cause serious lower limb injuries in many activities, such as automobile collisions and underbody explosions to military vehicles. The present study aims to compare the biomechanical responses of the mainstream vehicle occupant dummies with the human body lower limb model and analyze their robustness and applicability for assessing lower limb injury risk in under-foot impact loading environments.
Methods
The Hybrid III model, the test device for human occupant restraint (THOR) model, and a hybrid human body model with the human active lower limb model were adopted for under-foot impact analysis regarding different impact velocities and initial lower limb postures.
Results
The results show that the 2 dummy models have larger peak tibial axial force and higher sensitivity to the impact velocities and initial postures than the human lower limb model. In particular, the Hybrid III dummy model presented extremely larger peak tibial axial forces than the human lower limb model. In the case of minimal difference in tibial axial force, Hybrid III's tibial axial force (7.5 KN) is still 312.5% that of human active lower limb's (2.4 KN). Even with closer peak tibial axial force values, the biomechanical response curve shapes of the THOR model show significant differences from the human lower limb model.
Conclusion
Based on the present results, the Hybrid III dummy cannot be used to evaluate the lower limb injury risk in under-foot loading environments. In contrast, potential improvement in ankle biofidelity and related soft tissues of the THOR dummy can be implemented in the future for better applicability.
目的 在汽车碰撞和军用车辆车底爆炸等许多活动中，足下冲击载荷可导致严重的下肢损伤。本研究旨在比较主流车内乘员假人与人体下肢模型的生物力学响应，并分析其在足底冲击载荷环境下评估下肢损伤风险的稳健性和适用性。结果结果表明，与人体下肢模型相比，这两种假人模型的胫骨轴向力峰值更大，对冲击速度和初始姿势的敏感性更高。尤其是混合动力 III 假人模型的胫骨轴向力峰值比人体下肢模型大得多。在胫骨轴向力差异极小的情况下，Hybrid III 的胫骨轴向力（7.5 千牛）仍是人类活动下肢（2.4 千牛）的 312.5%。即使胫骨轴向力峰值更接近，THOR 模型的生物力学响应曲线形状与人类下肢模型仍有显著差异。相反，未来可以对 THOR 假人的踝关节生物保真度和相关软组织进行潜在改进，以提高其适用性。
{"title":"Investigation on vehicle occupant dummy applicability for under-foot impact loading conditions","authors":"Teng-Fei Tian , Fu-Hao Mo , Hao-Yang Su , Can Huang , Hui Zhao , Jun Liu , Bo Shang , Kui Li , Jin-Long Qiu","doi":"10.1016/j.cjtee.2024.02.002","DOIUrl":"10.1016/j.cjtee.2024.02.002","url":null,"abstract":"<div><h3>Purpose</h3><p>Under-foot impact loadings can cause serious lower limb injuries in many activities, such as automobile collisions and underbody explosions to military vehicles. The present study aims to compare the biomechanical responses of the mainstream vehicle occupant dummies with the human body lower limb model and analyze their robustness and applicability for assessing lower limb injury risk in under-foot impact loading environments.</p></div><div><h3>Methods</h3><p>The Hybrid III model, the test device for human occupant restraint (THOR) model, and a hybrid human body model with the human active lower limb model were adopted for under-foot impact analysis regarding different impact velocities and initial lower limb postures.</p></div><div><h3>Results</h3><p>The results show that the 2 dummy models have larger peak tibial axial force and higher sensitivity to the impact velocities and initial postures than the human lower limb model. In particular, the Hybrid III dummy model presented extremely larger peak tibial axial forces than the human lower limb model. In the case of minimal difference in tibial axial force, Hybrid III's tibial axial force (7.5 KN) is still 312.5% that of human active lower limb's (2.4 KN). Even with closer peak tibial axial force values, the biomechanical response curve shapes of the THOR model show significant differences from the human lower limb model.</p></div><div><h3>Conclusion</h3><p>Based on the present results, the Hybrid III dummy cannot be used to evaluate the lower limb injury risk in under-foot loading environments. In contrast, potential improvement in ankle biofidelity and related soft tissues of the THOR dummy can be implemented in the future for better applicability.</p></div>","PeriodicalId":51555,"journal":{"name":"Chinese Journal of Traumatology","volume":"27 4","pages":"Pages 235-241"},"PeriodicalIF":1.8,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1008127524000087/pdfft?md5=7df9e04a6fbbb8a1426d0c4b99381dcc&pid=1-s2.0-S1008127524000087-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140463576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1016/S1008-1275(24)00071-3
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Pub Date : 2024-07-01DOI: 10.1016/j.cjtee.2024.02.004
Mozhgan Seif , Sedigheh Edalat , Ali Majidpour Azad Shirazi , Somayeh Alipouri , Mohsen Bayati
Purpose
Road traffic accidents pose a global challenge with substantial human and economic costs. Iran experiences a high incidence of road traffic injuries, leading to a significant burden on society. This study aims to predict the future burden of road traffic injuries in Iran until 2030, providing valuable insights for policy-making and interventions to improve road safety and reduce the associated human and economic costs.
Methods
This analytical study utilized time series models, specifically autoregressive integrated moving average (ARIMA) and artificial neural networks (ANNs), to predict the burden of road traffic accidents by analyzing past data to identify patterns and trends in Iran until 2030. The required data related to prevalence, death, and disability-adjusted life years (DALYs) rates were collected from the Institute for Health Metrics and Evaluation database and analyzed using R software and relevant modeling and statistical analysis packages.
Results
Both prediction models, ARIMA and ANNs indicate that the prevalence rates (per 100,000) of all road traffic injuries, except for motorcyclist road injuries which have an almost flat trend, remaining at around 430, increase by 2030. Based on estimations of both models, the rates of death and DALYs due to motor vehicle and pedestrian road traffic injuries decrease. For motor vehicle road injuries, estimated trends decrease to approximately 520 DALYs and 10 deaths. Also, for pedestrian road injuries these rates reached approximately 300 DALYs and 6 deaths, according to the models. For cyclists and other road traffic injuries, the predicted DALY rates by the ANN model increase to almost 50 and 8, while predictions conducted by the ARIMA model show a static trend, remaining at 40 and approximately 6.5. Moreover, these rates for the prediction of death rate by the ANN model increased to 0.6 and 0.1, while predictions conducted by the ARIMA model show a static trend, remaining at 0.43 and 0.07. According to the ANN model, the predicted rates of DALY and death for motorcyclists decrease to 100 and approximately 2.7, respectively. On the other hand, predictions made by the ARIMA model show a static trend, with rates remaining at 200 and approximately 3.2, respectively.
Conclusion
The prevalence of road traffic injuries is predicted to increase, while the death and DALY rates of road traffic injuries show different patterns. Effective intervention programs and safety measures are necessary to prevent and reduce road traffic accidents. Different interventions should be designed and implemented specifically for different groups of pedestrians, cyclists, motorcyclists, and motor vehicle drivers.
目的道路交通事故是一项全球性挑战，在全球造成巨大的人员和经济损失。伊朗的道路交通伤害发生率很高，给社会造成了沉重负担。本研究旨在预测伊朗未来至 2030 年的道路交通伤害负担，为改善道路安全、降低相关人力和经济成本的政策制定和干预措施提供有价值的见解：本分析研究利用时间序列模型，特别是自回归综合移动平均线（ARIMA）和人工神经网络（ANN），通过分析过去的数据来预测道路交通事故的负担，从而确定伊朗到 2030 年的模式和趋势。所需的发病率、死亡率和残疾调整生命年（DALYs）率相关数据来自健康指标与评估研究所数据库，并使用 R 软件及相关建模和统计分析软件包进行分析：ARIMA和ANN两种预测模型均表明，到2030年，除摩托车驾驶员道路交通伤害的趋势几乎持平，保持在430左右外，其他所有道路交通伤害的发生率（每10万人）都将上升。根据这两个模型的估计，机动车和行人道路交通伤害造成的死亡率和残疾调整寿命年数都会下降。就机动车道路交通伤害而言，估计趋势是减少到约 520 DALYs 和 10 例死亡。此外，根据模型，行人道路交通伤害的死亡率约为 300 DALYs 和 6 例死亡。对于骑自行车者和其他道路交通伤害，ANN 模型预测的残疾调整寿命年数增加到近 50 年和 8 年，而 ARIMA 模型的预测则呈现静态趋势，保持在 40 年和约 6.5 年。此外，根据 ANN 模型预测的死亡率分别增加到 0.6 和 0.1，而根据 ARIMA 模型预测的死亡率则呈静态趋势，分别保持在 0.43 和 0.07。根据 ANN 模型，摩托车驾驶员的 DALY 和死亡率预测值分别下降到 100 和约 2.7。另一方面，ARIMA 模型的预测结果显示出静态趋势，死亡率分别保持在 200 和约 3.2：结论：预计道路交通伤害的发生率将上升，而道路交通伤害的死亡率和残疾调整寿命年率却呈现出不同的模式。预防和减少道路交通事故需要有效的干预计划和安全措施。应针对行人、骑自行车者、骑摩托车者和机动车驾驶员等不同群体设计和实施不同的干预措施。
{"title":"Prediction of the burden of road traffic injuries in Iran by 2030: Prevalence, death, and disability-adjusted life years","authors":"Mozhgan Seif , Sedigheh Edalat , Ali Majidpour Azad Shirazi , Somayeh Alipouri , Mohsen Bayati","doi":"10.1016/j.cjtee.2024.02.004","DOIUrl":"10.1016/j.cjtee.2024.02.004","url":null,"abstract":"<div><h3>Purpose</h3><p>Road traffic accidents pose a global challenge with substantial human and economic costs. Iran experiences a high incidence of road traffic injuries, leading to a significant burden on society. This study aims to predict the future burden of road traffic injuries in Iran until 2030, providing valuable insights for policy-making and interventions to improve road safety and reduce the associated human and economic costs.</p></div><div><h3>Methods</h3><p>This analytical study utilized time series models, specifically autoregressive integrated moving average (ARIMA) and artificial neural networks (ANNs), to predict the burden of road traffic accidents by analyzing past data to identify patterns and trends in Iran until 2030. The required data related to prevalence, death, and disability-adjusted life years (DALYs) rates were collected from the Institute for Health Metrics and Evaluation database and analyzed using R software and relevant modeling and statistical analysis packages.</p></div><div><h3>Results</h3><p>Both prediction models, ARIMA and ANNs indicate that the prevalence rates (per 100,000) of all road traffic injuries, except for motorcyclist road injuries which have an almost flat trend, remaining at around 430, increase by 2030. Based on estimations of both models, the rates of death and DALYs due to motor vehicle and pedestrian road traffic injuries decrease. For motor vehicle road injuries, estimated trends decrease to approximately 520 DALYs and 10 deaths. Also, for pedestrian road injuries these rates reached approximately 300 DALYs and 6 deaths, according to the models. For cyclists and other road traffic injuries, the predicted DALY rates by the ANN model increase to almost 50 and 8, while predictions conducted by the ARIMA model show a static trend, remaining at 40 and approximately 6.5. Moreover, these rates for the prediction of death rate by the ANN model increased to 0.6 and 0.1, while predictions conducted by the ARIMA model show a static trend, remaining at 0.43 and 0.07. According to the ANN model, the predicted rates of DALY and death for motorcyclists decrease to 100 and approximately 2.7, respectively. On the other hand, predictions made by the ARIMA model show a static trend, with rates remaining at 200 and approximately 3.2, respectively.</p></div><div><h3>Conclusion</h3><p>The prevalence of road traffic injuries is predicted to increase, while the death and DALY rates of road traffic injuries show different patterns. Effective intervention programs and safety measures are necessary to prevent and reduce road traffic accidents. Different interventions should be designed and implemented specifically for different groups of pedestrians, cyclists, motorcyclists, and motor vehicle drivers.</p></div>","PeriodicalId":51555,"journal":{"name":"Chinese Journal of Traumatology","volume":"27 4","pages":"Pages 242-248"},"PeriodicalIF":1.8,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1008127524000105/pdfft?md5=883a4eb2de840eae416c51c81af87db8&pid=1-s2.0-S1008127524000105-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140177595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tibial stress fracture associated with knee osteoarthritis is an unusual and difficult clinical scenario. There is no clear existing treatment guideline for this uncommon clinical disease. The aim of this study is to review the impact of various treatment options for patients with advanced knee osteoarthritis associated with proximal tibial stress fracture.
Methods
The study was performed using the databases of PubMed and Scopus. Methodological index for non-randomized studies score was used to evaluate the included studies’ bias. The concluded data included the treatment approach, reported outcome measure, and time to fracture union. The literature search was started in December 2021 and accomplished in January 2022. A narrative description of the different methods and comparison of their results were done.
Results
Out of total assessed 69 studies, 9 studies were included in our review. The commonest treatment approach used was total knee arthroplasty by long tibial stem extension. The mean preoperative knee society score and knee functional score were 30.62 and 23.17, respectively. The mean postoperative knee society knee score was 86.87, while the functional score was 83.52. The average reported time to achieve fracture union was 4 months (a range of 2.07 – 5.50 months).
Conclusion
The optimal clinical outcome for treating either acute or mobile tibial stress fracture in patients with advanced knee osteoarthritis can be achieved with long stem total knee arthroplasty. However, due to heterogeneity of data, comparison of different treatment options for chronic proximal tibial stress fracture mal-union/non-union coexisting with knee osteoarthritic and such inferences need to be judged cautiously.
{"title":"Management of proximal tibial stress fracture associated with advanced knee osteoarthritis: A systematic review","authors":"Mukesh Kumar Saini , Mahendra Singh , Devendra Singh , Prem Manohar Seervi , Pera Jayavardhan Reddy , Neelam Ramana Reddy","doi":"10.1016/j.cjtee.2023.07.002","DOIUrl":"10.1016/j.cjtee.2023.07.002","url":null,"abstract":"<div><h3>Purpose</h3><p>Tibial stress fracture associated with knee osteoarthritis is an unusual and difficult clinical scenario. There is no clear existing treatment guideline for this uncommon clinical disease. The aim of this study is to review the impact of various treatment options for patients with advanced knee osteoarthritis associated with proximal tibial stress fracture.</p></div><div><h3>Methods</h3><p>The study was performed using the databases of PubMed and Scopus. Methodological index for non-randomized studies score was used to evaluate the included studies’ bias. The concluded data included the treatment approach, reported outcome measure, and time to fracture union. The literature search was started in December 2021 and accomplished in January 2022. A narrative description of the different methods and comparison of their results were done.</p></div><div><h3>Results</h3><p>Out of total assessed 69 studies, 9 studies were included in our review. The commonest treatment approach used was total knee arthroplasty by long tibial stem extension. The mean preoperative knee society score and knee functional score were 30.62 and 23.17, respectively. The mean postoperative knee society knee score was 86.87, while the functional score was 83.52. The average reported time to achieve fracture union was 4 months (a range of 2.07 – 5.50 months).</p></div><div><h3>Conclusion</h3><p>The optimal clinical outcome for treating either acute or mobile tibial stress fracture in patients with advanced knee osteoarthritis can be achieved with long stem total knee arthroplasty. However, due to heterogeneity of data, comparison of different treatment options for chronic proximal tibial stress fracture mal-union/non-union coexisting with knee osteoarthritic and such inferences need to be judged cautiously.</p></div>","PeriodicalId":51555,"journal":{"name":"Chinese Journal of Traumatology","volume":"27 3","pages":"Pages 147-152"},"PeriodicalIF":2.1,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1008127523000688/pdfft?md5=6c2fb0167b3060a7d30f923a033415c7&pid=1-s2.0-S1008127523000688-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9995002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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