"Muscular branches from the intercostal nerves of the respective intercostal space (T1-T11), which run with the intercostal vessels under the costal groove in between the internal and innermost intercostal muscles."
Expected headings
"Blood supply"
"Action"
"The innermost intercostal muscles are the most deep muscle of the three intercostal muscles and arise from the inner margin of the costal groove of the rib above. The fibres run in a downwards, backwards and lateral (like the internal intercostal muscles and perpendicular to the external intercostal muscles) direction and insert into the superior border of the rib below. Some authors describe the muscle continuing over several ribs and intercostal spaces, as opposed to the internal and external intercostal muscles which only span each intercostal space 1."