muscles of the back

Layers of back muscles

Superficial, intermediate, deep

List the superficial back muscles

Trapezius, latissimus dorsi, levator scapulae, rhomboid major & minor

Superficial layer general function

Movement of scapula & upper limb

Trapezius function

Elevates, retracts & depresses scapula, upward & downward rotation of scapula

Latissimus dorsi function

Extends, abducts & medially rotates arm, extends trunk (from flexion)

Levator scapulae function

Elevation & downward rotation of scapula, lateral flexion of neck

Rhomboid major & minor function

Retraction & downward rotation of scapula, fixes scapula to thoracic wall

List the intermediate back muscles

Serratus posterior superior, serratus posterior inferior

Intermediate back muscles general function

Movement of ribs (breathing)

Serratus posterior superior function

Elevates ribs 2-5 (inspiration), fixes ribs during movement

Serratus posterior inferior function

Depresses ribs 9-12 (expiration), fixes ribs during movement

list the deep back muscles

Erector spinae, transversospinalis (multifidus & rotatores), splenius (capitis & cervicis), deep rotators

Deep layer general function

Movement & stability of vertebral column

Erector spinae function

Extends vertebral column, maintains upright posture, lateral flexion of trunk

Transversospinalis (multifidus & rotatores) function

Extends vertebral column, rotates vertebrae to opposite side, maintains posture & stability

Splenius (capitis & cervicis) function

Extends head & neck, rotates head to same side, lateral flexion of neck

Deep rotators function

Rotate vertebrae to opposite side, proprioception & stability