title: Unpredictability of fighter pilots' g duration tolerance by anthropometric and physiological characteristics.
abstract: BACKGROUND
  While the factors affecting fighter pilots' G level tolerance have been widely accepted, the factors affecting fighter pilots' G duration tolerance have not been well understood.
  
  
  METHODS
  Thirty-eight subjects wearing anti-G suits were exposed to sustained high G forces using a centrifuge. The subjects exerted AGSM and decelerated the centrifuge when they reached the point of loss of peripheral vision. The G profile consisted of a +2.3 G onset rate, +7.3 G single plateau, and -1.6 G offset rate. Each subject's G tolerance time was recorded and the relationship between the tolerance time and the subject's anthropometric and physiological factors were analyzed.
  
  
  RESULTS
  The mean tolerance time of the 38 subjects was 31.6 s, and the min and max tolerance times were 20 s and 58 s, respectively. The correlation analysis indicated that none of the factors had statistically significant correlations with the subjects' G duration tolerance. Stepwise multiple regression analysis showed that G duration tolerance was not dependent on any personal factors of the subjects. After the values of personal factors were simplified into 0 or 1, the t-test analysis showed that subjects' heights were inversely correlated with G duration tolerance at a statistically significant level. However, a logistic regression analysis suggested that the effect of the height factor to a pilot's G duration tolerance was too weak to be used as a predictor of a pilot's G tolerance.
  
  
  CONCLUSIONS
  Fighter pilots' G duration tolerance could not be predicted by pilots' anthropometric and physiological factors.
authors.forename: Myunghwan
authors.initials: M
authors.lastname: Park
authors.forename: Seunghoon
authors.initials: S
authors.lastname: Yoo
authors.forename: Hyeongju
authors.initials: H
authors.lastname: Seol
authors.forename: Cheonyoung
authors.initials: C
authors.lastname: Kim
authors.forename: Youngseok
authors.initials: Y
authors.lastname: Hong
mesh_terms: D000054:Acceleration; D000222:Adaptation, Physiological; D000328:Adult; D000337:Aerospace Medicine; D000886:Anthropometry; D001359:Aviation; D002498:Centrifugation; D003654:Deceleration; D006112:Gravitation; D006801:Humans; D008297:Male; D008889:Military Personnel; D011481:Protective Clothing; D056910:Republic of Korea; D013997:Time Factors