Deep layer - Posterior Pectoral Girdle

• Posterior muscles - Deep layer:

  • Rhomboid major
  • Rhomboid minor
  • Levator scapulae

  
• Rhomboid Minor Origin: Spinous process of C7 - T1 (and supraspinous ligaments in between)

  So

  Rhomboid Major Origin: Spinous process of T2 - T5 (and supraspinous ligaments in between)
• Levator scapular and rhomboid major and minor:

  • all NS is dorsal scapular nerve (c5)
  • all do medial rotation and retraction (LS does elevation as well)
  • LS originates from transverse process whereas RM's originate from spinous process
  • their insertions are continuous (LS is between superior angle and spine of scapula, R Minor is at level of spine of scapula, R Major is between inferior angle and spine of scapula)
  • R minor and major have continuous origins (including supraspinous ligaments) - minor is c7 and t1, major is t2 - t5
  • LS goes down and lateral, RM's go obliquely down and lateral