Writing postures in left-handers: inverters are hand-crossers.

A behavioural approach shows that the inverted hand-writing posture typical of many left-handers is one element of a well-patterned bimanual strategy including (i) counterclockwise rotation of the page; (ii) horizontal orientation of the active forearm on the page; and (iii) positioning of the non-writing hand just below the beginning of the line of writing. The strategy as a whole is liable to represent an adaptation to the necessity of writing with an adduction movement, rather than the symptom of any neurological particularity.