title: Comparative analysis: effects of positive and negative lateral acceleration on isometric fatigue in the forearm.
abstract: The purpose of this investigation was to determine the difference, if any, produced by +/- 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 experiment was designed to measure the forearm strength, endurance, recovery from fatigue, and surface electrical activity of six subjects during +/- 2 Gy acceleration.
  
  
  RESULTS
  isometric performance was degraded during -2 Gy acceleration compared to + 2 Gy acceleration. The percentage drop in center frequency of the EMG signal was determined to be unreliable as a fatigue index during lateral acceleration. When head and shoulder restraints were used during lateral maneuvers, they were a factor in pilot performance, with + 2 Gy being superior to -2 Gy. This study suggested a way of analyzing the EMG signals that may permit quantification of isometric fatigue during lateral acceleration.
mesh_terms: D000054:Acceleration / Q000009:adverse effects*; D000328:Adult; D000337:Aerospace Medicine; D004576:Electromyography; D005221:Fatigue / Q000209:etiology / Q000503:physiopathology*; D005542:Forearm; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D009119:Muscle Contraction; D013997:Time Factors