Back Muscles w/ pictures
Spinalis
O: Common origin I: Spines of lumbar vertebrae to spines of upper thoracic vertebrae between T2 and L2 (occasionally up to cervical vertebrae) N: Spinal nerves Fx: Extends the vertebral column *Part of Erector Spinae
Rhomboideus Major
O: Spines of T2-T5 I: Medial border of scapula N: Dosal Scapular nerve Fx: Fix, retract, and rotate scapula
Latissimus Dorsi
O: Spines of T7-Sacrum, iliac crest, 2 ribs I: Intertubercular sulcus of humerus N: Thoracodorsal nerve Fx: Extends, adducts, and medially rotates the arm
Levator Scapulae
O: Transverse processes of C1-C4 I: Medial border of scapula above the root of the spine N: Dorsal Scapular nerve Fx: Fixes and elevates the scapula; flexes the neck laterally
Multifidus
O: Vertebral arches from C2-S4 I: Spines along the entire vertebral column from C2-S4 N: Spinal nerves Fx: Laterally flexes, rotates, and extends the vertebral column
Illiocostalis
O: Common origin I: Lower 6 ribs, upper 6 ribs, transverse process of the lower cervical vertebrae N: Spinal nerves Fx: Extends and laterally flexes the spine *Part of Erector Spinae
Quadratus Lumborum
O: Iliolumbar ligament and iliac crest I: Transverse process of L1-L4 and the lowermost rib N: Spinal nerves Fx: Laterally flexes the spine
Rectus Capitis Posterior Minor
O: Posterior tubercle of C1 I: Occipital bone just medial to RCP major N: Suboccipital nerve Fx: Extends the head
Splenius Cervicis
O: Spines of T1-T6 I: Transverse processes of C1-C4 N: Middle and lower cervical nerves Fx: Laterally flexes, rotates, and extends the head and neck
Rectus Capitis Posterior Major
O: Spinous process of C2 I: Medial to the superior oblique on the occipital bone N: Suboccipital nerve Fx: Extension and rotation of the head
Superior Oblique
O: Transverse process of C1 I: Occipital bone N: Suboccipital nerve Fx: Laterally flexes the head (tilts)
Semispinalis
O: Transverse processes of C2-T12 I: Spines of superior vertebrae N: Spinal nerves Fx: Rotates and extends the vertebral column of the trunk
Semispinalis Capitis
O: Transverse processes of T1-T6 I: Medial part of the occipital bone between the superior and inferior nuchal lines N: Spinal nerves Fx: Rotates and extends the head and neck
Rhomboideus Minor
O: Spine of T1 I: Medial border of scapula N: Dorsal Scapular nerve Fx: Fix, retract, and rotate scapula
Trapezius
O: Occipital bone, ligamentum nuchae, spines of thoracic vertebrae I: Spine and acromion process of scapula, part of clavicle N: Accessory nerve (XI) Fx: Fixes, elevates, rotates scapula; extends head
Inferior Oblique
O: Spinal process of C2 I: Transverse process of C1 N: Suboccipital nerve Fx: Rotates the head
Longissimus
O: Common origin I: Transverse processes of thoracic, lumbar, and cervical vertebrae to the mastoid process of the skull N: Spinal nerves Fx: Extend and laterally flex the spine; extent and rotates the head *Part of Erector Spinae
Splenius Capitis
O: Lower part of ligamentum nuchae I: Lateral aspect of the mastoid process and lateral part of the superior nuchal line of the skull N: Middle and lower cervical nerves Fx: Laterally flexes, rotates, and extends the head and neck
