2.4.1. Innermost Intercostal Muscles: Transversus Thoracis
Overview of the Innermost Intercostal Muscles
The remaining muscles of the thorax are described in different ways in different textbooks, so here I have tried to simplify the learning process by categorising them all as 'innermost intercostal muscles'. I think it's really suitable to group them in this way because they all lie deeper than the external and internal intercostal muscles. It's important to note that there are three sets of 'innermost intercostal muscles', and they don't form one continuous muscle layer from front to back. However, the position of each muscle set is distinctive within the ribcage - let's have a look at the first set - transversus thoracis.