A study of whiplash injury occurrence mechanisms using human head-neck finite element model (Analysis of factors on the gender difference)
From worldwide statistical data of whiplash injuries in the rear-end impact accidents, females have been found to be at a higher risk than males and the reason for the same is an ongoing research topic. First, we created finite element model of the head and neck of a 50th %ile Japanese adult female...
| Main Authors: | , |
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| Format: | Article |
| Language: | Japanese |
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The Japan Society of Mechanical Engineers
2019-06-01
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| Series: | Nihon Kikai Gakkai ronbunshu |
| Subjects: | |
| Online Access: | https://www.jstage.jst.go.jp/article/transjsme/85/875/85_19-00059/_pdf/-char/en |
| _version_ | 1798015116559515648 |
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| author | Junji HASEGAWA Naoyuki KUBOTA |
| author_facet | Junji HASEGAWA Naoyuki KUBOTA |
| author_sort | Junji HASEGAWA |
| collection | DOAJ |
| description | From worldwide statistical data of whiplash injuries in the rear-end impact accidents, females have been found to be at a higher risk than males and the reason for the same is an ongoing research topic. First, we created finite element model of the head and neck of a 50th %ile Japanese adult female (JAF50) by scaling an existing 50th %ile (JAM50) male model. The activity level of neck muscles before a rear-end impact was determined using the L36 of DOE method, which held a neutral posture of the head with the relaxed muscles under 1G condition. Subsequently, the head and neck behaviors of both the models were validated using the volunteer's rear-end impact test data. Comparing both the results using a new index (S - θmax), which measured the S-shape deformation of the neck during rear-end impacts, the model results were found to have the same trends as that of the volunteer's test data. JAF50 had a higher (S - θmax) value than JAM50, which means that a female neck undergoes larger S-shaped mode than a male. This index value difference between the genders was due to the difference in their muscle forces while maintaining a neutral posture of the head. This difference in the muscle forces, however, was not proportional to only the head mass ratio of the two genders. As a result of the investigation of the underlying reason, the neck muscle force ratio of each gender at the neutral position was roughly related to mass ratio × neck column cross-sectional area ratio × neck length ratio. If the ratio (female to male) of neck circumferences was 3: 4, the female muscle force could be nearly twice less than that of a male. We also estimated the muscle activity for each gender assuming the same (S - θmax) = 15 ° at the rear-end impact of Δ V = 5 km/h. It was found that a female's muscle activity is about twice that of a males for the same rear-end impact conditions. |
| first_indexed | 2024-04-11T15:29:23Z |
| format | Article |
| id | doaj.art-987b423ee6034a5393dfe30210594e69 |
| institution | Directory Open Access Journal |
| issn | 2187-9761 |
| language | Japanese |
| last_indexed | 2024-04-11T15:29:23Z |
| publishDate | 2019-06-01 |
| publisher | The Japan Society of Mechanical Engineers |
| record_format | Article |
| series | Nihon Kikai Gakkai ronbunshu |
| spelling | doaj.art-987b423ee6034a5393dfe30210594e692022-12-22T04:16:11ZjpnThe Japan Society of Mechanical EngineersNihon Kikai Gakkai ronbunshu2187-97612019-06-018587519-0005919-0005910.1299/transjsme.19-00059transjsmeA study of whiplash injury occurrence mechanisms using human head-neck finite element model (Analysis of factors on the gender difference)Junji HASEGAWA0Naoyuki KUBOTA1Department of Mechanical Systems Engineering, Graduate School of System Design, Tokyo Metropolitan UniversityDepartment of Mechanical Systems Engineering, Graduate School of System Design, Tokyo Metropolitan UniversityFrom worldwide statistical data of whiplash injuries in the rear-end impact accidents, females have been found to be at a higher risk than males and the reason for the same is an ongoing research topic. First, we created finite element model of the head and neck of a 50th %ile Japanese adult female (JAF50) by scaling an existing 50th %ile (JAM50) male model. The activity level of neck muscles before a rear-end impact was determined using the L36 of DOE method, which held a neutral posture of the head with the relaxed muscles under 1G condition. Subsequently, the head and neck behaviors of both the models were validated using the volunteer's rear-end impact test data. Comparing both the results using a new index (S - θmax), which measured the S-shape deformation of the neck during rear-end impacts, the model results were found to have the same trends as that of the volunteer's test data. JAF50 had a higher (S - θmax) value than JAM50, which means that a female neck undergoes larger S-shaped mode than a male. This index value difference between the genders was due to the difference in their muscle forces while maintaining a neutral posture of the head. This difference in the muscle forces, however, was not proportional to only the head mass ratio of the two genders. As a result of the investigation of the underlying reason, the neck muscle force ratio of each gender at the neutral position was roughly related to mass ratio × neck column cross-sectional area ratio × neck length ratio. If the ratio (female to male) of neck circumferences was 3: 4, the female muscle force could be nearly twice less than that of a male. We also estimated the muscle activity for each gender assuming the same (S - θmax) = 15 ° at the rear-end impact of Δ V = 5 km/h. It was found that a female's muscle activity is about twice that of a males for the same rear-end impact conditions.https://www.jstage.jst.go.jp/article/transjsme/85/875/85_19-00059/_pdf/-char/enbiomechanicswhiplash injuriesfinite element methodhead-neckmusclesrear impactgender difference |
| spellingShingle | Junji HASEGAWA Naoyuki KUBOTA A study of whiplash injury occurrence mechanisms using human head-neck finite element model (Analysis of factors on the gender difference) Nihon Kikai Gakkai ronbunshu biomechanics whiplash injuries finite element method head-neck muscles rear impact gender difference |
| title | A study of whiplash injury occurrence mechanisms using human head-neck finite element model (Analysis of factors on the gender difference) |
| title_full | A study of whiplash injury occurrence mechanisms using human head-neck finite element model (Analysis of factors on the gender difference) |
| title_fullStr | A study of whiplash injury occurrence mechanisms using human head-neck finite element model (Analysis of factors on the gender difference) |
| title_full_unstemmed | A study of whiplash injury occurrence mechanisms using human head-neck finite element model (Analysis of factors on the gender difference) |
| title_short | A study of whiplash injury occurrence mechanisms using human head-neck finite element model (Analysis of factors on the gender difference) |
| title_sort | study of whiplash injury occurrence mechanisms using human head neck finite element model analysis of factors on the gender difference |
| topic | biomechanics whiplash injuries finite element method head-neck muscles rear impact gender difference |
| url | https://www.jstage.jst.go.jp/article/transjsme/85/875/85_19-00059/_pdf/-char/en |
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