Editing Facial Action Coding System (section)

==== Head movement codes ====
{| class="wikitable sortable"
|-
! AU number !! FACS name !! Action
|-
| 51 || Head turn left ||
|-
| 52 || Head turn right ||
|-
| 53 || Head up ||
|-
| 54 || Head down ||
|-
| 55 || Head tilt left ||
|-
| M55 || Head tilt left || The onset of the symmetrical 14 is immediately preceded or accompanied by a head tilt to the left.
|-
| 56 || Head tilt right ||
|-
| M56 || Head tilt right || The onset of the symmetrical 14 is immediately preceded or accompanied by a head tilt to the right.
|-
| 57 || Head forward ||
|-
| M57 || Head thrust forward || The onset of 17+24 is immediately preceded, accompanied, or followed by a head thrust forward.
|-
| 58 || Head back ||
|-
| M59 || Head shake up and down || The onset of 17+24 is immediately preceded, accompanied, or followed by an up-down head shake (nod).
|-
| M60 || Head shake side to side || The onset of 17+24 is immediately preceded, accompanied, or followed by a side to side head shake.
|-
| M83 || Head upward and to the side || The onset of the symmetrical 14 is immediately preceded or accompanied by a movement of the head, upward and turned or tilted to either the left or right.
|}