Effects of Fall Height and Impact Strategy on Energy Absorption Ratio Between Shoulder Joint and Elbow Joint

Abstract

Falls onto an outstretched hand are the leading cause of upper extremity injury. However, little information is available regarding the effects of fall height and impact strategy on energy absorption ratio between shoulder joint and elbow joint. Twelve male subjects participated in the study. The subjects were asked to perform simulated falls from three different fall heights (5, 10 and 15) using three different conscious strategies, namely Conscious Elbow Dominant Strategy, Conscious Shoulder Dominant Strategy, and Conscious Intermediate Dominant Strategy, corresponding with three different theoretical strategies, namely Elbow Dominant Strategy, Intermediate Dominant Strategy and Shoulder Dominant Strategy for biomechanical analysis. For a fall height of 5 cm, the Elbow Dominant Strategy was found better than other impact strategies, resulting in an Optimal Energy Absorption Ratio of 1.60. For an increased fall height of 10 cm, the Intermediate Dominant Strategy was found better than other impact strategies, with an Optimal Energy Absorption Ratio of 1.99. Finally, for a fall height of 15 cm, the Shoulder Dominant Strategy was found better than other impact strategies, with an Optimal Energy Absorption Ratio of 2.40. The findings presented in this study provide a useful source of reference to clinicians, sports coaches and instructors in devising optimal fall strategies for minimizing the risk of upper extremity injuries in the event of forward falls onto the outstretched hand.