Non-specific nature of specific language impairment: a review of the literature with regard to concomitant motor impairments.

In the light of emerging suggestions that language and motor deficits may co-occur, the literature on specific language impairment (SLI) was reviewed to investigate the prevalence of co-morbidity between SLI and poor limb motor skill in children diagnosed with language impairments. An extensive literature search was undertaken and the subsequent findings evaluated with particular reference to issues surrounding symptom co-occurrence, as well as to theoretical and aetiological accounts of SLI. Clearly substantial co-morbidity exists between SLI and poor motor skill, suggesting that SLI is not a specific disorder of language, but rather that children with SLI experience a broader range of difficulties, of which motor incoordination is one. Current theoretical explanations of SLI do not account fully for such wide-ranging difficulties and it may be useful in the future to focus on a more detailed explanation in terms of shared cognitive processes or neuromaturational delay to understand further the nature of the disorder, to explain it theoretically and to deal with it practically.