The Effects of Supination and Pronation on Oblique Fractures

Abstract

The purpose of this research is to determine how the landing orientation of an outstretched arm affects the fracture of the ulna and radius. In this study, three left arms and three right arms were dissected for testing. Distally, the wrist, and proximally, the ulna and radius, were set in place using a two-part fiberglass epoxy resin. For consistency, all left arms were fractured in a supinated position using an MTS machine to apply a specific load to test stiffness and cause fractures. These results were then compared to fracture angles and forces found in the right arms which were tested in a pronated position. The expectations were that a pronated orientation would lead to a shallower fracture angle. Based on the tests and analyzed data, the experiment data showed no major correlation between orientation and a significant difference in stiffness or fracture force namely due to a small sample size. Further research would involve further testing beyond the three sets of paired arms to gather more data to find a possible correlation as well as relating the forces to possible damage to ligaments in the elbow and shoulder.