Impaired tongue strength and endurance in developmental verbal dyspraxia: a physiological analysis.

Tongue strength and endurance measures were obtained from six children with developmental verbal dyspraxia (DVD) aged between 5;6 years and 11;5 years and compared to those achieved by six normal speaking controls matched for age and sex. The instrument for measuring tongue strength comprised an air-filled soft rubber bulb connected to a pressure transducer. The results indicated that the DVD group had weaker lingual musculature than the controls. In addition the DVD subjects exhibited significantly reduced tongue strength endurance compared with the controls. Overall the findings support the hypothesis that a motor impairment forms at least part of the basis of DVD and may be indicative of the presence of a concomitant dysarthria in children with DVD, or may reflect an underspecification of the motor programme. The need for revision of contemporary taxonomies relating to childhood motor speech disorders is discussed.