Skip to main content

Pressure Breathing Without a Counter-Pressure Vest Does Not Impair Acceleration Tolerance Up to 9 G

Buy Article:

$30.00 plus tax (Refund Policy)


Balldin UI, O’Connor RB, Isdahl WM, Werchan PM. Pressure breathing without a counter-pressure vest does not impair acceleration tolerance up to 9 G. Aviat Space Environ Med 2005; 76:456–462.

Introduction: This study was to determine whether safe and adequate G-protection by pressure breathing during G (PBG) could be maintained if the COMBAT EDGE counter-pressure vest were eliminated to ensure aircrew do not unnecessarily endure a possible in-flight discomfort or distraction. Methods: Centrifuge exposures up to +9 Gz were completed by 11 subjects, including 5 F-15 aircrew, using PBG at 60 mmHg pressure with and without the counter-pressure vest. Additional G-exposures using pressures of 0, 30, and 45 mmHg were performed without the vest. Results: Elimination of the COMBAT EDGE counter-pressure vest did not significantly reduce G-tolerance. During gradual onset G exposure, the mean G level reached with PBG was 8.4 G without the vest and 8.2 G with the vest. In comparison, 6.7 G was reached without PBG. Mean times at G with rapid onset G exposure were 59 and 60 s, respectively, compared with 49 s without PBG. PBG, with or without the vest, was preferred by all test subjects. PBG at 60 mmHg produced the highest G protection and was preferred by the test subjects over lesser pressures. Subjects reported no adverse effects from the use of PBG without chest counter-pressure. Conclusion: The use of PBG and the anti-G straining manuever (AGSM) together enhances G tolerance and comfort more than AGSM alone. Elimination of the counter-pressure vest during use of PBG does not hinder an individual’s ability to reach +9 Gz or complete a short duration simulated aerial combat maneuver G exposure. Further research is needed to determine if use of PBG without chest counter-pressure increases fatigue during multiple sorties or produces other aeromedical problems in operational environments.

Keywords: G protection; G tolerance; G-LOC; acceleration; anti-G suit; counter-pressure vest; pressure breathing; thorax counter-pressure

Document Type: Research Article

Publication date: May 1, 2005

More about this publication?

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more