24 May 2008
Brittany Coats, Ph.D., and Susan S. Margulies, Ph.D.
Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania
Object. Falls are the most common accident scenario in young children as well as the most common history
provided in child abuse cases. Understanding the biomechanics of falls provides clinicians with objective data to aid
in their diagnosis of accidental or inflicted trauma. The objective of this study was to determine impact forces and
angular accelerations associated with low-height falls in infants.
Methods. An instrumented anthropomorphic infant surrogate was created to measure the forces and 3D angular
accelerations associated with falls from low heights (0.3–0.9 m) onto a mattress, carpet pad, or concrete.
Results. Although height significantly increased peak angular acceleration (αp), change in peak-to-peak angular
velocity, time duration associated with the change in velocity, and peak impact force (Fp) for head-first drops onto a
carpet pad or concrete, none of these variables were significantly affected by height when dropped onto a mattress.
The αp was not significantly different for drops onto a carpet pad and concrete from 0.6 or 0.9 m due to compression
of the carpet pad. Surprisingly, sagittal αp was equaled or surpassed by axial αp.
Conclusions. These are the first 3D angular acceleration and impact force data available for head impact in
infants from low-height falls. A future study involving a computational model of the infant head will use the loads
measured in this study to predict the probability of occipital skull fracture on impact from head-first low-height falls.
Together, these studies will provide data that will aid clinicians in the evaluation of accidental and inflicted head injuries,
and will contribute to the design of safer environments for children.