Back Muscles (Origin, Insertion, Action, Innervation)

Spinalis

(Erector Spinae aponeurosis muscle) Origin - spinous processes at inferior vertebral levels Insertion - spinous processes 4-8 , superior vertebral levels and base of skull Action - extends and laterally bends the trunk and neck Nerve - DPR of spinal nerves C2 - L3

Longissimus

(Erector spinae aponeurosis muscle) Origin -erector spinae aponeurosis, Tp's as it ascends the trunk Insertion - tp 6 levels superior to origin and mastoid process. Action - extends and laterally bends the trunk Nerve - DPR of C1 to S1

Iliocostalis

(Erector spinae aponeurosis) Origin- iliac crest and sacrum via spinae aponeurosis Insertion - angles of ribs 6 levels superior to origin Action - extends and laterally bend the trunk and neck Nerve - DPR C4 to S5

What are the erector spinae aponeurosis muscles?

Iliocostalis Longissimus Spinalis

TP to SP is?

Opposite side

Splenius

Origin - Ligamentum Nuchae and Spines C7 - T6 Insertion- Cervicis: posterior tubercles of C1-C2 vertebrae Capitis:Mastoid process and lateral aspect of superior nuchal line Action - Extends and laterally bends neck and head, rotates head to same side Nerve - dorsal primary rami of spinal nerves C2 - C6

Obliques Capitis inferior

Origin - Spinous process of the axis Insertion - Transverse process of the atlas Action - rotates head to the same side on the atlanto-axial joint Nerve - Sub occipital Nerve (DPR of C1

Obliques Capitis superior

Origin - Transverse process of the atlas Insertion - occipital bone above inferior nuchal line Action - rotates head to same side Nerve - Sub occipital nerve (DPR of C1)

Latissimus Dorsi

Origin - Vertebral spines from T7 to the sacrum, thoracolumbar fascia, lower 3 or 4 ribs , inferior angle of the scapula Insertion - anterior humerus in the intertubercular groove Action - extends, adducts, and rotates the arm medially Nerve - thoracodorsal

Rhomboideus minor

Origin - inferior end of the ligamentum nuchae, spines of vertebrae C7 and T1 Insertion - medial border of the scapula at the root of the spine of the spine of the scapula Action - retracts, elevates and rotates the scapula inferiorly Nerve - dorsal scapular nerve

Trapezius

Origin - medial third of the superior nuchal line, external occipital protuberance ligamentum nuchae, spinous processes of vertebrae c7 - T12 Insertion - lateral third of the clavicle, medial side of the acromion and the upper crest of the scapular spine, tubercle of the scapular spine Action - elevates or the depresses the scapula, rotates the scapula superiorly, retracts scapula extends head on neck Nerve - motor:spinal accessory XI proprioception c3-c4

Multifidus

Origin - posterior sacrum, PSIS then TPs as muscle ascends the trunk, then articular processes in the C spine Insertion- spinous processes 2 vertebra levels superior to origin (deep MF) 4 vertebral levels superior to their origin (superficial MF) Action - extend and laterally bend the trunk and neck. Rotate to opposite side, stabilizes individual vertebral segments Nerve - DPR of spinal nerves C1 - L5

Rectus Capitis Posterior Minor

Origin - posterior tubercle of atlas Insertion - inferior nuchal line medially Action - extends the head Nerve - sub occipital nerve (DPR of C1)

Rhomboideus major

Origin - spines of vertebrae T2 - T5 Insertion- medial border of the scapula inferior to the spine of the scapula Action - retracts, elevates and rotates the scapula inferiorly Nerve - dorsal scapular nerve

Posterior Scalene

Origin - transverse processes c5 - c7 Insertion - 2nd rib Action - elevates the second rib, flexes and laterally bends the neck Nerve - C7 - C8

Middle Scalene

Origin - transverse processes of C2 - C7 Insertion - 1st rib Action - Elevates the first rib, flexes and laterally bends the neck Nerve - C3 - C8

Anterior Scalene

Origin - transverse processes of C3 - C6 Insertion - 1st rib Action - Elevates the first rib, flexes and laterally bends the neck Nerve - C5 - C7

levator scapulae

Origin - transverse processes of the c1 to C4 Insertion - medial border of the scapula from the superior angle to the spine Action - elevates the scapula Nerve - dorsal scapular nerve

Rectus Capitis Posterior Major

Origin -spinous process of axis Insertion - inferior nuchal line Action - Extends the head, rotate to same side Nerve - Sub occipital nerve (DPR of C1)

Semispinalis

Origin- Cervicis: Tp's T6 to T1 Capitis: TP's T6 to C4 Insertion - Cervicis: SP's 4-6 vertebrae above origin ending at C2 SP Capitis: Posterior skull between nuchal lines Action - extends the trunk neck / head, and laterally bends them and rotates to opposite side Nerve - DPR of Spinal nerves C1 to T 12

Sp to TP

Same side

What innervates all occipital triangle muscles?

Sub occipital nerve (DPR of C1)