Assessment and intervention for problems in sign production

When teachers were asked some years ago what they found was the commonest problem in working through sign with children with intellectual disabilities (IDs), they nominated difficulties in motor production (Grove & McDougall, 1989), a problem which was also raised by McEwen and Lloyd (1990) in a review of motor demands for signing in the field of AAC. Co-morbidity of impairments is a characteristic of developmental disability: for example, there is a high rate of praxic disorder in autistic children (Bhat, Srinivasan, Woxholdt & Shield, 2016; Page & Boucher, 1998; see also Chapters 6 and 7, this volume). Signing involves a range of different motor skills. The locations (LOC), handshapes (HS), movements (MOV) and orientations (ORI) that form the basic building blocks of sign (known as “sign parameters”) require complex integration of fine motor skills. The meaning of a sign can change completely by altering one or more of these. For example, the sign for ‘I’ or ‘ME’ can be changed to the sign ‘MY’ or ‘MINE’ by altering the handshape from a ‘point’ handshape to a ‘flat’ or ‘fist’ handshape. In this way, the parameters of signs are considered the manual equivalent of phonology in spoken language.