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Published on: September 21, 2017
Biomechanics of the toddler head during low-height falls: an anthropomorphic dummy analysis
Nicole G Ibrahim1, Susan S Margulies
1Department of Bioengineering, The University of Pennsylvania, Philadelphia, Pennsylvania 19104-6321, USA.
Insights
Toddler head impacts from low-height falls show increased angular acceleration compared to infants, suggesting a higher risk of neurological impairment despite lower skull fracture rates. This research aids in understanding pediatric head injury mechanisms.
Area of Science:
- Pediatric Traumatology
- Biomechanics
- Child Injury Prevention
Background:
- Falls are the leading cause of closed head injuries in young children (2-4 years).
- Previous research indicated toddlers experience fewer skull fractures but more altered mental status than infants from similar low-height falls (
Purpose of the Study:
- To investigate age-dependent mechanical factors contributing to observed differences in head injuries between toddlers and infants.
- To quantify head kinematics during low-height falls in a toddler model.
Main Methods:
- An instrumented toddler dummy (18-month-old) was developed using anthropometric and biomechanical data.
- Peak angular acceleration was measured during falls (1, 2, 3 ft) onto carpet pad and concrete.
- Results were compared to data from a 6-week-old infant dummy.
Main Results:
- Toddler head angular acceleration doubled between 1-2 ft fall heights and was higher in sagittal/horizontal planes.
- Concrete impacts yielded greater acceleration and shorter durations than carpet impacts.
- Toddler head accelerations were over twice those of infants, correlating with higher loss of consciousness rates; however, thicker toddler skulls may reduce fracture risk.
Conclusions:
- Toddlers are likely less susceptible to skull fractures but more vulnerable to neurological impairment than infants in low-height falls.
- Differences in head kinematics and skull properties influence injury patterns.
- Findings highlight the need for targeted injury prevention strategies for young children.
Object:
Falls are the most common environmental setting for closed head injuries in children between 2 and 4 years of age. The authors previously found that toddlers had fewer skull fractures and scalp/facial soft-tissue injuries, and more frequent altered mental status than infants for the same low-height falls (
Methods:
To identify potential age-dependent mechanical load factors that may be responsible for these clinical findings, the authors created an instrumented dummy representing an 18-month-old child using published toddler anthropometry and mechanical properties of the skull and neck, and they measured peak angular acceleration during low-height falls (1, 2, and 3 ft) onto carpet pad and concrete. They compared these results from occiput-first impacts to previously obtained values measured in a 6-week-old infant dummy.
Results:
Peak angular acceleration of the toddler dummy head was largest in the sagittal and horizontal directions and increased significantly (around 2-fold) with fall height between 1 and 2 ft. Impacts onto concrete produced larger peak angular accelerations and smaller impact durations than those onto carpet pad. When compared with previously measured infant drops, toddler head accelerations were more than double those of the infant from the same height onto the same surface, likely contributing to the higher incidence of loss of consciousness reported in toddlers. Furthermore, the toddler impact forces were larger than those in the infant, but because of the thicker toddler skull, the risk of skull fracture from low-height falls is likely lower in toddlers compared with infants.
Conclusions:
If similar fracture limits and brain tissue injury thresholds between infants and toddlers are assumed, it is expected that for impact events, the toddler is likely less vulnerable to skull fracture but more vulnerable to neurological impairment compared with the infant.
