Apraxia

A motor speech disorder in which the brain has difficulty coordinating the muscle movements needed to produce speech, despite the muscles themselves not being weak. The person knows what they want to say but their brain has difficulty planning and sequencing the precise movements of the tongue, lips, jaw, and palate required for intelligible speech. Childhood apraxia of speech (CAS) is present from birth and affects speech development, while acquired apraxia can result from stroke, brain injury, or neurological conditions. Apraxia is a common reason individuals use augmentative and alternative communication, and it requires consideration in the design of AAC interfaces — particularly for motor planning, where consistent placement of vocabulary items allows users to develop automatic movement patterns.