Here we have the dorsal or backside view of the right scapula. The most prominent feature here is the spine of the scapula, which works with two major muscles. It is the origin, essentially the anchor, of the deltoid muscle, the primary muscle of the shoulder. It is also the insertion of your trapezius, so the scapula moves along with the trapezius muscle when you decide to shrug your shoulders. Above and below the spine of the scapula, we have two depressions, the supraspinous fossa and the infraspinous fossa. Both are origins for their sister muscles. The supraspinatous muscle attaches to the humerus, the arm bone, and helps you raise your arm laterally. The infraspinatous is much larger and helps you externally rotate your arm so your inside elbows face out. If you sit in a desk at a computer all day like me, this muscle gets virtually no action. But it is begging to go to the party. Along the lateral border you can see a little bit of shading marking a ridge, which helps to separate the infraspinatous from the teres major and teres minor muscles. The teres minor attaches to the small space between this ridge and the actual edge of the bone. On the small edge of the bone at the bottom, below the lateral border, is where the teres major attaches. Enough for now!