Editing SignWriting (section)

=== Hand movement ===

Hundreds of arrows of various sorts are used to indicate movement of the hands through space. Movement notation gets quite complex, and because it is more exact than it needs to be for any one sign language, different people may choose to write the same sign in different ways.

For movement with the left hand, the Δ-shaped arrowhead is hollow (white); for movement with the right hand, it is solid (black). When both hands move as one, an open (Λ-shaped) arrowhead is used.

As with orientation, movement arrows distinguish two planes: Movement in the vertical plane (up & down) is represented by arrows with double stems, as at the bottom of the diagram at left, while single-stemmed arrows represent movement parallel to the floor (to & fro). In addition, movement in a diagonal plane uses modified double-stemmed arrows: A cross bar on the stem indicates that the motion is away as well up or down, and a solid dot indicates approaching motion. To & fro movement that also goes over or under something uses modified single-stemmed arrows, with the part of the arrow representing near motion thicker than the rest. These are iconic, but conventionalized, and so need to be learned individually.

Straight movements are in one of eight directions for either plane, as in the eight principal directions of a compass. A long straight arrow indicates movement from the elbow, a short arrow with a cross bar behind it indicates motion from the wrist, and a simple short arrow indicates a small movement. (Doubled, in opposite directions, these can show nodding from the wrist.) A secondary curved arrow crossing the main arrow shows that the arm twists while it moves. (Doubled, in opposite directions, these can show shaking of the hand.) Arrows can turn, curve, zigzag, and loop-the-loop.