g-force induced loss of consciousness (abbreviated as G-LOC, pronounced "JEE-lock") is a term generally used in aerospace physiology to describe a loss of consciousness occurring from excessive and sustained g-forces draining blood away from the brain causing cerebral hypoxia.
The condition is most likely to affect pilots of high performance fighter and aerobatic aircraft or astronauts but is possible on some extreme amusement park rides.
Relative incapacitation is the period in which the consciousness has been regained, but the person is confused and remains unable to perform simple tasks.
Upon regaining cerebral blood flow, the G-LOC victim usually experiences myoclonic convulsions (often called the ‘funky chicken’) and often full amnesia of the event is experienced.
A trained, fit individual wearing a g suit and practicing the straining manoeuvre can, with some difficulty, sustain up to 12-14g without loss of consciousness.