Pediatric Material Properties: A Review of Human Child and Animal Surrogates

Abstract

Because pediatric tissue is difficult for researchers to obtain, the biomechanical responses of adult humans have been studied much more extensively than those of children. Piglets, chimpanzees, and other animals have been used as child surrogates, but the tissue properties and responses to impact forces obtained from these animals may not directly correlate with the human child, and this correlation is not well understood. Consequently, only a handful of human pediatric tissue properties are known. Child anthropomorphic test devices employed in automotive safety have been developed largely by scaling data obtained from adult human cadaveric tests, where various scaling methods have been used to account for differences in geometry, material properties, or a combination of these two parameters. Similar scaling techniques have also been implemented to develop injury assessment reference values for child anthropomorphic test devices. Nevertheless, these scaling techniques have not yet proven to be accurate, in part because of the lack of pediatric data. In this review, the properties of pediatric human and animal surrogate tissue that have been mechanically tested are evaluated. It was found that most of the pediatric tissue that has previously been tested pertains to the head, neck, cervical spine, and extremities. It is evident that some body regions, such as the head and neck, have been tested to some extent since injuries to these regions are critical from an injury perspective. On the other hand, there is limited pediatric data available for the thorax, abdomen, thoracic and lumbar spines and fetal-related tissue. This review presents the pediatric data available in the literature and highlights the body regions where further testing is needed.

In Vivo Assessment of Elasticity of Child Rib Cortical Bone Using Quantitative Computed Tomography

“…Such models could be used to assess mechanical loading on the thorax (e.g., for brace treatment or car crash accidents). However, the mechanical properties of pediatric thoracic tissues have been poorly studied due to difficulties in obtaining specimens to perform conventional tests [ 1 , 2 ]. Regarding specifically the rib cortical bone of children, mechanical data are extremely limited [ 1 ].…”

“…However, the mechanical properties of pediatric thoracic tissues have been poorly studied due to difficulties in obtaining specimens to perform conventional tests [ 1 , 2 ]. Regarding specifically the rib cortical bone of children, mechanical data are extremely limited [ 1 ]. To the authors' knowledge, only a handful of studies exploring pediatric rib mechanical properties can be found in the existing literature [ 3 – 5 ].…”