1.3. Movement
Movement is one of the main parameters of a sign’s sublexical structure besides hand configuration and location. Two main types of movement are path movement and hand-internal/secondary movement. Path movements are realized by flexions in the wrist, elbow, and shoulder joints; while hand-internal movements are produced by flexion of finger joints or rotation of forearm which leads to change in hand-orientation. The exact setting of a sign is necessarily changed by path movement but not by hand-internal movement. Additionally, if a sign has neither path nor hand-internal movement; it may have one of the following types of movement: (i) short back-and-forth repetitive movements that generally last shorter than two hundred milliseconds (see [Phonology - 2] for the prosodic function of this type of movement); (ii) non-manual movements (movement of head or torso) with no movement in hands [Phonology - 1.5.3.].