AIMTo observe the protection effect of a new combined anti-G measure which was composed of KH-x anti-G suit, unassisted PBG (positive pressure breathing for G, PBG) and PHP maneuver. The problem of fatigue and pain when using this measure was also discussed.

METHODSFive fully qualified centrifuge subjects were exposed to 5 groups of +Gz exposure: (1) relaxed tolerance, (2) KH-x and KT-x, (3) PBG, (4) 6.5 G 45 s, (5) 9.0 G 15 s. The subjective feeling of fatigue and pain induced by +Gz exposure was evaluated by the questionnaire after runs.

RESULTSThere was no incidents of G-induced lose of consciousness in this study. The protective effect of KH-x and KT-x was 2.3 G while it was 1.7 G for PBG. All the subjects have accomplished the 4th and 5th runs. The pain has developed on neck, waist, arm and hands. The problem of waist pain was very significant.

CONCLUSIONThe new combined anti-G measure could meet the requirement of +9.0 Gz protection for high performance plane. How to prevent the occurrence of neck injury and alleviate the pain induced by G when using this measure should be studied further.