Comparative Analysis of Positive and Negative Lateral Acceleration on Isometric Fatigue

摘要

The USAF Advanced Fighter Technology Integration F-16 is a six degree of freedom aircraft capable of lateral acceleration as well as conventional modes of flight. The purpose of this investigation was to determine the difference, if any, produced by positive and negative lateral (Gy) acceleration on forearm fatigue. The Dynamic Environment Simulator (DES) at the USAF Aerospace Medical Research Laboratory was used to create a lateral acceleration environment. The DES and surface electromyogram (EMG) techniques were used to measure any differences in isometric strength, endurance, and recovery from fatigue observed in the handgrip muscles of the right forearm under + or - 2 Gy acceleration. Also, quantification of the fatigue produced by + or - 2 Gy acceleration was investigated. The results of this study indicate that isometric performance was degraded under -2 Gy acceleration compared to +2 Gy acceleration. A reasonable explanation for the degradation was radial nerve entrapment during -2 Gy acceleration caused by the restraint system being used. The percentage drop in center frequency of the EMG signal was determined unreliable as a fatigue index under lateral acceleration.