气候变化领域集成服务门户(CCPortal): Biomechanical trade-offs in the pelvic floor constrain the evolution of the human birth canal

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DOI	10.1073/pnas.2022159118
	Biomechanical trade-offs in the pelvic floor constrain the evolution of the human birth canal
	Stansfield E.; Kumar K.; Mitteroecker P.; Grunstra N.D.S.
发表日期	2021
ISSN	00278424
卷号	118 期号:16
英文摘要	Compared with most other primates, humans are characterized by a tight fit between the maternal birth canal and the fetal head, leading to a relatively high risk of neonatal and maternal mortality and morbidities. Obstetric selection is thought to favor a spacious birth canal, whereas the source for opposing selection is frequently assumed to relate to bipedal locomotion. Another, yet under-investigated, hypothesis is that a more expansive birth canal suspends the soft tissue of the pelvic floor across a larger area, which is disadvantageous for continence and support of the weight of the inner organs and fetus. To test this “pelvic floor hypothesis,” we generated a finite element model of the human female pelvic floor and varied its radial size and thickness while keeping all else constant. This allowed us to study the effect of pelvic geometry on pelvic floor deflection (i.e., the amount of bending from the original position) and tissue stresses and stretches. Deflection grew disproportionately fast with increasing radial size, and stresses and stretches also increased. By contrast, an increase in thickness increased pelvic floor stiffness (i.e., the resistance to deformation), which reduced deflection but was unable to fully compensate for the effect of increasing radial size. Moreover, larger thicknesses increase the intra-abdominal pressure necessary for childbirth. Our results support the pelvic floor hypothesis and evince functional trade-offs affecting not only the size of the birth canal but also the thickness and stiffness of the pelvic floor. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	Biomechanics; Evolutionary trade-off; Finite element modeling; Human birth canal; Pelvic floor
语种	英语
scopus关键词	abdominal pressure; adult; article; biomechanics; childbirth; controlled study; female; finite element analysis; geometry; human; pelvis floor; physiological stress; rigidity; thickness
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/179810
作者单位	Department of Evolutionary Biology, University of Vienna, Vienna, 1090, Austria; Department of Civil, Architectural and Environmental Engineering, Cockrell School of Engineering, University of Texas at Austin, Austin, TX 78712-0273, United States; Konrad Lorenz Institute for Evolution and Cognition Research, Klosterneuburg, 3400, Austria; Mammal Collection, Natural History Museum Vienna, Vienna, 1010, Austria
推荐引用方式 GB/T 7714	Stansfield E.,Kumar K.,Mitteroecker P.,et al. Biomechanical trade-offs in the pelvic floor constrain the evolution of the human birth canal[J],2021,118(16).
APA	Stansfield E.,Kumar K.,Mitteroecker P.,&Grunstra N.D.S..(2021).Biomechanical trade-offs in the pelvic floor constrain the evolution of the human birth canal.Proceedings of the National Academy of Sciences of the United States of America,118(16).
MLA	Stansfield E.,et al."Biomechanical trade-offs in the pelvic floor constrain the evolution of the human birth canal".Proceedings of the National Academy of Sciences of the United States of America 118.16(2021).