The medial (vertebral) border is the longest of the three

borders of the scapula (see Figs. 1.6, 1.7, and 1.9A). It

extends from the superior angle to the inferior angle. The

border is slightly arched with a posterior convexity. This

border is intermediate in thickness between the superior

and lateral borders, measuring approximately 4 mm thick at

1 cm from the edge (26). The portion superior to the spine

forms an obtuse angle of approximately 145 degrees with

the portion inferior to the spine. The border has an anterior

and posterior lip, with an intermediate narrow area. The

anterior lip provides attachment for the serratus anterior

muscle. The posterior lip provides attachment for the

supraspinatus muscle above the spine and the infraspinatus

below the spine. The narrow area between the two lips provides insertion for the levator scapulae muscle above the triangular area, which marks the beginning of the spine. The

insertion of the levator scapulae may extend along the

major portion of the dorsal rim of the medial border superior to the spine (5,28). The rhomboid minor muscle

inserts on this edge inferior to the levator scapulae at the

level of the spine. The rhomboid major inserts on the rim

just inferior to the attachment of the rhomboid minor (and

inferior to the spine). The insertion of the rhomboid major

may extend along the major portion of the dorsal rim of the

medial border inferior to the spine (5,28). At the level of the

spine, the rhomboid minor also inserts into a fibrous arch

that attaches to the base of the spine.