Dynamic Bending Tolerance of the Human Forearm

Abstract

With the wide-spread use of supplemental restraint systems (airbags), occasional new injuries have developed because of the significant force associated with these systems upon deployment. Recent case studies have demonstrated forearm fractures associated with the deployment of the airbag. The present study was conducted to determine the tolerance of the human forearm under a dynamic bending mode. A total of 30 human cadaver forearm specimens were tested using three-point bending techniques to failure at 3.3 m/s and 7.6 m/s velocities. Results indicated significantly (p < 0.01) greater biomechanical parameters associated with males compared to females. The bending tolerance of the human forearm was found to be most highly correlated to bone mineral density and forearm weight. The mean failure bending moment for all specimens was 94 Nm - 41, but for smaller-sized occupants with lower bone mineral it was approximately 45 Nm. The present investigation offers quantitative information regarding tolerance of the human forearm useful for design of injury-mitigating devices.