Electromyographic investigation of the diaphragm and intercostal muscles in tetraplegics.

Local electromyographic activity has been demonstrated in the intercostal muscles of tetraplegic patients by using a combination of surface, fine-wire and intra-oesophageal diaphragmatic electrodes. This activity is first present and most evident in the lower chest, the point of maximum deformation in the tetraplegic's thorax. In patients with long standing injury the activity is present and prominent in the more superior intercostal muscles. We believe this activity to be reflex in character and that it develops and facilitates over time, so improving the ventilatory capacity of tetraplegics.