Infants and Children in the Adult World of Automobile Safety Design: Pediatric and Anatomical Considerations for Design of Child Restraints

  • Published: Journal of Biomechanics, Vol. 2, pp. 267-28, 1969
  • Authors: A R Burdi, D F Huelke, R G Snyder and G H Lowrey
  • Date Added: 09 Apr 2012
  • Last Update: 07 Dec 2015
  • Format: pdf


To identify general principles for child restraint systems based on the basic anatomical differences between the adult and child. To produce a profile of the infant and child to highlight age differences related to the design of child restraint systems.


Literature Review

Key Findings:

  • Infants and children are not miniature adults. Their anatomy differs from adults in a number of ways.
  • The design of occupant restraint systems needs to be based on child anatomy not the anatomy of the adult.
  • The frequency of head injuries in children in automobile accidents may be due to the child's proportionately large head and higher center of gravity.
  • Observations that the child's head is relatively massive and supported poorly from below have been implicated in head snapping with rapid body deceleration, which can traumatize related nerves, blood vessels, and spinal cord segments.
  • The relative lack of skull protection, due to the fact that infants’ skulls are not an intact bony case but a series of broadly spaced elastic bones, contributes to brain injuries in young children.
  • Differences in size, structure, shape, and biomechanical properties of the infant, child, and adult pelvic skeleton must be considered in terms of lap belt design, position, and vehicle anchorage. Key differences include insufficient space in the pelvic-thigh angle for adequate positioning of the adult lap belt on the child.
  • Unlike the adult, the organs of the chest are housed in an elastic and highly compressible thoracic cage, and are extremely vulnerable to non-penetrating impacts to the chest. The thoracic cage is not amenable to direct trauma or loading of webbed restraints in children.
  • The most effective restraint systems for children are those which distribute impact forces over a large portion of the body.