• arm fracture;
  • biomechanics;
  • bone density;
  • childhood obesity;
  • stochastic computer simulation

Objective:  To determine the role of the biomechanical factors of force of impact, bone strength, fall height and surface stiffness on the risk of forearm fracture in obese children compared to non-obese children.

Methodology:  Anthropometric and dual-energy X-ray absorptiometry bone density data from 50 boys (25 obese pair-matched with 25 non-obese subjects) aged 4−17 years were entered into a rheological-stochastic simulation model of arm impact.

Results:  Obese children were shown to be at 1.7 times greater risk of fracture compared to non-obese children. Lower fall heights and softer impact surfaces were found not to reduce the relative risk of fracture between obese and non-obese children.

Conclusions:  Environmental modifications are unlikely to lower the risk of arm fracture in obese children to the same levels experienced by non-obese children. The best option available for obese children to reduce fracture risk is to take steps to attain a healthy bodyweight.