| System 1 | System 2 | System 3 | System 4 | System 5 | |||||
|---|---|---|---|---|---|---|---|---|---|
| Verbal definition | Pictorial description | Descriptive terms | Vernacular description | ||||||
| AGARD symbolsb | Heart diplacement | ||||||||
| A force applied to the posterior part of the trunk acting forward with respect to the subject and perpendicular to the mean spine produces a forward acceleration | Forward acceleration or forward acting force | Eyeballs in | +Gx | Moves toward back | Forward acceleration | Transverse A-P G Supine G Chest to back G | Sternumward | Surge | |
| A force applied to the anterior part of the trunk acting backward with respect to the subject and perpendicular to the mean spine produces a backward acceleration | Backward acceleration or backward acting force | Eyeballs out | -Gx | Moves toward front | Backward acceleration | Transverse P-A G Prone G Back to chest G | Spineward | - | |
| A force applied to the left surface of the subjects body, acting in a rightward direction and essentially perpendicular to the subject's mean spin produces a rightward acceleration | Rightward acceleration or rightward acting force | Eyeballs left | +Gy | Moves toward left | Right lateral acceleration | Left lateral G | - | Left sway | |
| A force applied to the right surface of the subject's body, acting in a leftward direction and essentially perpendicular to the subject's mean spine produces a leftward acceleration | Leftward acceleration or leftward acting force | Eyeballs right | -Gy | Moves toward right | Left lateral acceleration | Right lateral G | - | Right sway | |
| A force applied to the buttocks, thighs, and or feet, acting in a headward direction with respect to the subject and essentially parallel to the subject's mean spine produces a headward acceleration | Headward acceleration or headward acting force | Eyeballs down | +Gs | Moves toward feet | Headward acceleration | Positive G | Tailward | - | |
| A force applied to the shoulders, thighs, and feet of a seated human acting in a tailward direction with respect to the subject and essentially parallel to the subject's mean spine produces a tailward acceleration. | Tailward acceleration or tailward acting force | Eyeballs up | -Gs | Moves toward head | Footward acceleration | Negative G | Headward | Heave | |
| Forces that alternate in direction and produce alternately forward and backward motion of the subject, and that act essentially perpendicular to the spine, produce front to back acceleration | Front-to-back oscillating force or acceleration | - | +/- Gx | Oscillates fore-and-aft within thorax | - | - | - | - | |
| Forces that alternate in direction and produce alternately side to side motion of the subject, and that act essentially perpendicular to the spine, produce side to side acceleration | Side-to-side oscillating force or acceleration | - | +/- Gy | Oscillates side-to-side within thorax | - | - | - | - | |
| Forces that alternate in direction and produce alternately head to tail motion of the subject, and that act essentially parallel to the spine, produce head to tail acceleration | Head-to-tail oscillating force or acceleration | - | +/- Gs | Oscillates head-to-tail within thorax | - | - | - | - | |
| A rotational moment or couple that produces a head left motion of the subject that lies essentially in the frontal (shoulder-to-shoulder) plane produces a head left cartwheeling angular acceleration | Head left cartwheeling moment or acceleration | - | -Rx | Top tilts toward right shoulder | - | - | - | - | |
| A rotational moment or couple that produces a head right motion of the subject that lies essentially in the frontal (shoulder-to-shoulder) plane produces a head right cartwheeling angular acceleration | Head right cartwheeling moment or acceleration | - | +Rx | Top tilts toward left shoulder | - | - | - | - | |
| A rotational moment or couple that produces a head-forward feet backward tumbling motion of the subject that lies essentially in the saggital plane produces a forward somersaulting angular acceleration | Forward somersaulting moment or acceleration | - | -Ry | Top tilts toward spine | - | - | - | - | |
| A rotational moment or couple that produces a head-backward feet-forward tumbling motion of the subject that lies essentially in the saggital plane produces a backward somersaulting angular acceleration | Backward somersaulting moment or acceleration | - | +Ry | Top tilts toward sternum | - | - | - | - | |
| A rotational moment or couple that produces a right-turn motion of the subject about the spine in the saggital plane produces a right twisting angular acceleration and will be named a right turn pirouetting force or couple | Right twisting moment or acceleration | - | +Rs | Twists toward subject's left | - | - | - | - | |
| A rotational moment or couple that produces a left-turn motion of the subject about the spine in the saggital plane produces a left twisting angular acceleration | Left twisting moment or acceleration | - | -Rs | Twists toward subject's right | - | - | - | - | |