Origins
Origin of Trapezius
Occipital Bone, Nuchal Ligament, and Spinous Process C7-T12
Insertion of Levator Scapulae
Medial Border of Scapula above spine
Action of Latissimus Dorsi
Extension, adduction, and medial rotation of Humerus
Innervation of Rhomboid Major
Dorsal Scapular Nerve
Layer of Levator Scapulae
Extrinsic
Origin of Latissimus Dorsi
Spinous Processes of lower T6-sacral vertebrae via thoracolumbar fascia, posterior 1/3 of iliac crest and last 3-4 ribs
Insertion of Serratus Posterior Inferior
Ribs 9-12
Action of Rhomboid Minor
Scapular retraction/adduction, downward rotation, and stabilization
Innervation of Latissimus Dorsi
Thoracodorsal Nerve
Layer of Transversospinalis
Intermediate
Origin of Serratus Posterior Superior
Nuchal Ligament and Spinous Processes of T1-T3
Insertion of Splenius Cervicis
Transverse processes of C1-C3
Action of Erector Spinae
Bilaterally: Extend Vertebral Column
Unilaterally: Lateral Flexion of Vertebral Column
Innervation of Serratus Posterior Superior
Intercostal Nerves 2-5
Layer of Iliocostalis
Intrinsic
Origin of Splenius Capitis
Nuchal Ligament and Spinous Processes of C7-T3
Insertion of Multifidus
Pass superomedially to spinous processes 2-4 segments
Action of Semispinalis
Bilaterally: Extend Thoracic and Cervical Vertebral Column
Unilaterally: Contralateral rotation of Trunk and Neck
Innervation of Serratus Posterior Inferior
Intercostal Nerves 9-11 and Subcostal Nerve
Layer of Rectus Capitis Posterior Minor
Suboccipital
Origin of Rectus Capitis Posterior Major
C2 Spinous Process
Insertion of Obliquus Capitis Inferior
Transverse process of C1
Action of Obliquus Capitis
Technically: Extending Cervical Spine
Practically: Posture Stabilization
Innervation of Rotatores
Dorsal Rami
Layer of Spinalis
Intrinsic