Secondary movements are local or hand-internal movements. As said before, they can result in handshape and/or orientation changes.
The possible handshape changes can be categorized as follows: opening, closing, flattening, bending, wiggling, rubbing, and spreading movements.
In opening movements, the selected fingers change from a closed to an extended configuration. Various handshapes can be involved, for example F (medicine), 8 (gold), and 3 (flower).
a. medicine (handshape F)
b. gold (handshape 8)
c. flower (handshape 3)
In closing movements, the selected fingers change from an extended to closed configuration. Various handshapes can be involved, for example L (bird), 3 (speak), and 5 (understand).
a. bird (handshape L)
b. speak (handshape 3)
c. understand (handshape 5)
The selected fingers usually move together, but they can also move separately, one after the other. The former case is exemplified by the sign grasp, in which the fingers close together. The latter case is exemplified by the sign steal, in which the fingers close one after the other. This can occur with opening movement, too, as shown in the sign number.
a. grasp (fingers close together)
b. steal (fingers close one after the other)
c. number (fingers open one after the other)
In some signs, the selected fingers flex at base joints. This hand-internal movement is called flattening and is found, for example, in the sign rabbit.
rabbit
When the selected fingers flex at the base joint and extend repeatedly in an alternating way, a wiggling movement is produced. To illustrate, this type of secondary movement is found in the sign computer.
computer
Another possible handshape change is bending. This secondary movement occurs when the selected fingers flex at non-base joints. For example, it is found in the sign photo.
photo
Rubbing movements characterise signs in which the thumb applies friction to the other selected finger(s). A sign produced with rubbing movement is money.
money
Spreading movements occur when the handshape changes from a spread to an unspread configuration. This type of secondary movement can be observed in the sign scissors, in which index and middle fingers spread and unspread repeatedly.
scissors
Different types of handshape change can be phonologically contrastive. For example, the signs switch_on and switch_off are very similar signs and differ only in internal movement (opening in switch_on and closing in switch_off).
a. switch_on (opening)
b. switch_off (closing)
As shown by the videos above, the sign switch_on involves an opening movement from closed to open 5, whereas the sign switch_off involves a closing movement from open to closed 5.
The presence or absence of handshape change can create phonological contrasts. This can be seen in the minimal pair aunt - gratis: the only difference between these two signs is that aunt does not require any hand-internal movement, whereas free_of_charge requires an opening movement from closed 5 to handshape G.
a. aunt (without handshape change)
b. free_of_charge (withhandshape change)
The possible orientation changes can occur in three different ways: i) wrist rotation, ii) pivoting, and iii) nodding.
In wrist rotation, there is a change in palm orientation. This change can be from prone to supine (e.g. betray), from supine to prone (e.g. forbidden), or repeated from one position to the other (e.g. music).
a. betray (from prone to supine)
b. forbidden (from supine to prone)
c. music (supine/prone repeatedly)
In pivoting, there is a change in finger orientation. This change can be from radial to ulnar (e.g. impossible_pa_pa), from ulnar to radial (e.g. stupid), or repeated from one position to the other (e.g. motor).
a. impossible_pa_pa (from radial to ulnar)
b. stupid (from ulnar to radial)
c. motor (radial/ulnar repeatedly)
In nodding, there is a change in both palm and finger orientation. This change can be from palm to back (e.g. open), from back to palm (e.g. closed), or repeated from one position to the other (e.g. spring).
a. open (from palm to back)
b. closed (from back to palm)
c. spring (palm/back repeatedly)
Different types of orientation change can be phonologically contrastive. For instance, the signs hammer and key are very similar with the difference that in the former the closed G handshape repeatedly changes from back to palm (nodding), whereas in the latter the closed G handshape changes from prone to supine (wrist rotation).
a. hammer (nodding)
b. key (wrist rotation)
The presence or absence of handshape change can create phonological contrasts. For example, the two grammatical signs ix(dem) (LEXICON 3.6.1) and pe (LEXICON 3.6.1 and SYNTAX 3.4.2.1) are almost identical because they share the same handshape (G), relative orientation (tips), location (neutral space), and movement (toward a deictic or anaphoric locus in the neutral space). What distinguishes these two signs is that in ix(dem) no orientation change occurs, whereas in pe the G handshape changes from radial to ulnar (pivoting).
a. ix(dem) (without orientation change)
b. pe (with orientation change)