The respiratory abilities of a group of 20 subjects with a speech disorder resulting from severe closed head injury (CHI) were assessed using both spirometric and kinematic techniques and compared with those of a group of 20 non-neurologically impaired controls matched for age and gender. Results of the spirometric assessment showed that the CHI subjects as a group had lower vital capacities and lower forced expiratory volumes 1 second than the controls. Kinematic assessment also showed that the CHI subjects had problems co-ordinating the action of the rib-cage and abdomen when carrying out speech tasks such as vowel prolongations, syllable repetitions and reading. Results are discussed in terms of the effects of CHI on neuromuscular function.