Human shoulder development is adapted to obstetrical constraints.
Proc Natl Acad Sci U S A
; 119(16): e2114935119, 2022 04 19.
Article
em En
| MEDLINE
| ID: mdl-35412896
ABSTRACT
In humans, obstetrical difficulties arise from the large head and broad shoulders of the neonate relative to the maternal birth canal. Various characteristics of human cranial development, such as the relatively small head of neonates compared with adults and the delayed fusion of the metopic suture, have been suggested to reflect developmental adaptations to obstetrical constraints. On the other hand, it remains unknown whether the shoulders of humans also exhibit developmental features reflecting obstetrical adaptation. Here we address this question by tracking the development of shoulder width from fetal to adult stages in humans, chimpanzees, and Japanese macaques. Compared with nonhuman primates, shoulder development in humans follows a different trajectory, exhibiting reduced growth relative to trunk length before birth and enhanced growth after birth. This indicates that the perinatal developmental characteristics of the shoulders likely evolved to ease obstetrical difficulties such as shoulder dystocia in humans.
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Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Ombro
/
Distocia do Ombro
Tipo de estudo:
Etiology_studies
/
Risk_factors_studies
Limite:
Animals
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Female
/
Humans
/
Pregnancy
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Japão