Origin: Inner surface of one rib
Insertion: Inner surface of the second or third rib above, near its angle
Nerve: Intercostal nerves
The Subcostales (Infracostales) consist of muscular and aponeurotic fasciculi, which are usually well-developed only in the lower part of the thorax; each arises from the inner surface of one rib near its angle, and is inserted into the inner surface of the second or third rib below. Their fibers run in the same direction as those of the Intercostales interni.