Physiologic correlates of protection afforded by anti-G suits

A new uniform-pressure pneumatic anti-G suit (UPS) was compared with the standard CSU-13B/P anti-G suit, using measurements of: blood lactate, heart rate changes, and segmented lower-body blood pooling (by impedance plethysmography). Subjects were exposed to a series of gradual-onset-rate (GOR) runs (0.1 G.s-1), rapid-onset-rate (ROR) runs (6 G.s-1), and simulated aerial combat maneuvers (SACM) on the USAF School of Aerospace Medicine human-use centrifuge. All measured parameters and subjective reports indicated that increased protection was afforded by the UPS. The impedance plethysmography measurements indicated that prevention of blood pooling in all lower-body segments is the predominant mechanism whereby uniform pressure permits significantly longer times-to-fatigue during SACMs.