Comparative multibody dynamics analysis of falls from playground climbing frames

Abstract

This paper shows the utility of multibody dynamics in evaluating changes in injury related parameters of the head and lower limbs of children following falls from playground climbing frames. A particular fall case was used as a starting point to analyze the influence of surface properties, posture of the body at impact, and intermediate collisions against the climbing frame before impacting the ground. Simulations were made using the 6-year-old pedestrian MADYMO rigid body model and scaled head contact characteristics. Energy absorbing surfaces were shown to reduce injury severity parameters by up to 30-80% of those of rigid surfaces, depending on impact posture and surface. Collisions against components of a climbing frame during a fall can increase injury severity of the final impact of the head with the ground by more than 90%. Negligible changes are associated with lower limb injury risks when different surfacing materials are used. Computer reconstructions of actual falls that are intended to quantify the severity of physical injuries rely on accurate knowledge of initial conditions prior to falling, intermediate kinematics of the fall and the orientation of the body when it impacts against the ground. Multibody modelling proved to be a valuable tool to analyze the quality of eye-witness information and analyze the relative injury risk associated with changes in components influencing fall injuries from playground climbing frames. Such simulations can also support forensic investigations by evaluating alternative hypotheses for the sequence of kinematic motion of falls which result in known injuries.

The influence of dynamic response and brain deformation metrics on the occurrence of subdural hematoma in different regions of the brain

“…1 As there was some uncertainty surrounding the nature of the fall in some cases (other body parts contacting the ground first, for example), a sensitivity analysis was conducted based on the possible parameters leading to the head's contact with the hard surfaces. 1,7,24 This sensitivity analysis comprised running simulations without any body part bracing the fall, and various arm or leg positions that may have reduced the head velocity upon contact with the object that caused the SDH. The lowest head-contact velocity was used for the physical model simulations, as these were designated the "best possible scenario" for the simulations.…”

Paediatric bed fall computer simulation model development and validation

“…Forero Rueda andGilchrist (2009), O'Riordain et al (2003), Doorly and Gilchrist (2006) and Adamec et al (2010) reconstructed falls in MADYMO w based on eyewitness accounts and information collected from the scene of the fall. The subjects in these studies ranged in age from 6 to 76 years.…”

“…Computer simulation has been widely used by the automotive industry to study motor vehicle crash events, and has also been used in a few studies to investigate falls (O'Riordain et al 2003;Doorly and Gilchrist 2006;Schulz et al 2008;Doorly and Gilchrist 2009;Forero Rueda and Gilchrist 2009;Adamec et al 2010). The development of a paediatric bed fall computer model can lead to a deeper understanding of relationships between biomechanical factors, fall environment parameters, child parameters and potential for injury.…”

The Strain Rates in the Brain, Brainstem, Dura, and Skull under Dynamic Loadings

“…Finite element (FE) simulations provide a convincing framework for determining biomechanical responses of the head exposed to those high rated loads [5]. These numerical models have been introduced to predict brain deformation for different applied loads and study intracranial organ behavior under TBI conditions [6][7][8][9][10][11][12][13]. The biofidelity of such computational simulations is strictly related to the accuracy of the material properties used to model these tissues.…”