Transverse forces supine +Gx "Lying on your back, Eye Balls In" Recommended high acceleration position
Transverse forces prone -Gx "Lying face down, Eye Balls Out" Second-best high acceleration position
Positive longitudinal +Gz "Sitting with head above heart, Eye Balls Up"
Third-best high acceleration position
Negative longitudinal -Gz "Standing on your head, Eye Balls Down" Worst high acceleration position
Yellow is seconds until unconsciousness, Orange is seconds of "tolerance" (whatever that means), Red is seconds until injury.
For example, an astronaut in the recommended +Gx lying on back position would have 5 seconds of consciousness at 14g, 5 seconds of tolerance at 27g and 10 seconds until injury at 48g.
Chart from a 1963 Douglas report