Injury Criteria for Dynamic Hyperextension of the Female Elbow Joint

This paper describes an analysis to develop dynamic hyperextension injury criteria for the female elbow joint. Dynamic hyperextension tests were performed on 24 female cadaver elbow joints. The energy source was a drop tower utilizing a three-point bending configuration to apply elbow bending moments matching the previously conducted side airbag tests. Post-test necropsy showed that 16 of the 24 elbow joint tests resulted in injuries. Injury severity ranged from minor cartilage damage to more moderate joint dislocations and severe transverse fractures of the distal humerus. Peak elbow bending moments ranged from 42.4 Nm to 146.3 Nm. Peak bending moment proved to be a significant indicator of any elbow injury p 0.02 as well as elbow joint dislocation p 0.01. Logistic regression analyses were used to develop single and multiple variate injury risk functions. Using peak moment data for the entire test population, a 50 risk of obtaining any elbow injury was found at 56 Nm while a 50 risk of sustaining an elbow joint dislocation was found at 93 Nm for the female population. It is anticipated that this study will provide researchers with additional injury criteria for assessing upper extremity injury risk caused by both military and automotive side airbag deployments.