Back Muscles O.i.i.a

Front 1

Extrinsic back muscles

Back 1

Involved with movements of the upper limbs and thoracic wall. In general are innervated by anterior rami of spinal nerves. Includes superficial and intermediate group.

Front 2

Superficial Group of extrinsic muscles

Back 2

Trapezius
Latissimus dorsi
levator scapulae
rhomboid major and minor

Front 3

Intermediate group of extrinsic muscles

Back 3

Superior posterior inferior/superior

Front 4

Intrinsic back muscle

Back 4

Are the deep back muscles that are innervated by the posterior rami of spinal nerves and they support and move the vertebral column and participate in moving the head.

Front 5

Deep back muscles

Back 5

Suboccipital
Splenius
Erector Spinae
-iliocostalis
-longissimus
-spinalis

Front 6

Trapezius

Back 6

O: Superior nuchal line, external occipital protuberance, ligamentum nuchae
I: Lateral, 1/3 of clavicle, acromion and spine of scapula
I: Motor - accessory nerve [XI]
B: branch of transverse cervical artery
A: Assists in rotating the scapula during abduction of humerus above horizontal; upper fibers elevate, middle fibers adduct, and lower fibers depress scapula

Front 7

Latissimus Dorsi

Back 7

O: Spinous process of T7 to L5 and sacrum, iliac crest and ribs 5 to 7.
I: Floor intertubercular sulcus of humerus
I: Thoracodorsal nerve
A: Extends, adducts and medially rotates humerus
B: Thoracodorsal artery

Front 8

Levator Scapulae

Back 8

O: Transverse process of C1 to C4
I: Upper portion medial border of scapula
I: Dorsal scapular nerve
A: Elevates Scapula
B: Transverse cervical artery

Front 9

Rhomboid Major and Minor

Back 9

O: Spinous Processes T2-T5/ Spinous Process C7-T1
I: Medial border of scapula at the spine
I: Dorsal scapular nerve (C4/C5)
A: Retracts (adducts) and elevates the scapula
B: Dosral Scapular Artery

Front 10

Serratus Posterior Superior

Back 10

O: Spinous process of C7-T3 and supraspinous ligaments
I: Upper border of ribs 2-5
I: Anterior Rami of upper thoracic nerves
A: Elevates ribs
B: Perforating branches of intercostal arteries

Front 11

Serratus Posterior Inferior

Back 11

O: Spinous processes T6-L3
I: Lower border of ribs 9-12
I: Anterior rami of lower thoracic nerves
A: Depresses ribs
B: Perforating branches of lumbar arteries

Front 12

Splenius Capitis

Back 12

O: Lower half of ligamentum nuchae, spinous processes C7-T4
I: Mastoid process of skull
I: Posterior (dorsal) rami, middle cervicle nerves
A: Together -Draw head backward, extending neck
Individually - rotate head side to side
B: Branches of occipital artery

Front 13

Splenius Cervices

Back 13

O: Spinous processes of T3-T6
I: Transverse Process of C1-C3
I: Dorsal rami lower cervical nerves
A: together extend neck, individually draw and rotate head (to face same side)
B: branches of occopital artery

Front 14

Erector Spinae Muscles

Back 14

Largest group of intrinsic back muscle. Covered by thoracolumbar fascia and the serratus posterior inferior, rhomboid and splenius muscles. They are the primary extensors of the vertebral column. Are all innervated by dorsal rami of spinal nerves.
1) illiocostalis (lumborum/thoracis/cervices)
2) longissimus (thoracis/ cervices/ capitis)
3) Spinalis (thoracis/ cervices/ catpitis)

Front 15

Transversopinalis Muscles

Back 15

Run obliquely and upward and medially from transverse processes to spinous process. Contain three major subgroups - semispinalis, multifidus and rotatores muscles.

Front 16

Semispinalis (Capitis/thoracis/capitus)

Back 16

Capitis:
I: Dorsal Rami
A: extends the head
Thoracis:
I: Dorsal Rami
A: Extends the cervical vertebral column

Front 17

Multifidus

Back 17

Span length of vertebral column, passing from a lateral point of origin and medially attaching to spinous processes. Best developed in lumbar region.
All innervated by dorsal rami.

Front 18

Rotatores

Back 18

Beneath multifidus. Present throughout vertebral column, best developed in thoracic region. Innervate by dorsal rami.

Front 19

What are the rotator cuff muscles?

Back 19

SITS - infraspinatous, supraspinatous, teres minor and subscapularis

Front 20

How is the humerus abducted?

Back 20

0-15 degree - supraspinatous
15-90 degree - deltoid
Above horizontal - trapezius and serratus anterior.

Front 21

Supraspinatous

Back 21

Origin - supraspinous fossa of scapula
Insertion -superior facet of greater tubercle of humerus
Artery - suprascapular artery
Nerve -suprascapular nerve
Actions - initiation of abduction of the arm (raising arm)

Front 22

Infraspinatous

Back 22

Origin - lateral border of the scapula
Insertion - Inferior facet of greater tubercle of the humerus
Artery - posterior circumflex humeral artery and the circumflex scapular artery
Nerve - axillary nerve
Actions - laterally rotates the arm, adducts the forearm, stabilizes humerus

Front 23

Subscapularis

Back 23

Origin -subscapular fossa
Insertion - lesser tubercle of humerus
Artery - Transverse cervical artery, subscapular artery
Nerve - upper subscapular nerve, lower subscapular nerve (C5, C6)
Actions - internally (medially) rotates humerus; stabilizes shoulder

Front 24

Teres Minor

Back 24

Origin lateral border of the scapula
Insertion inferior facet of greater tubercle of the humerus
Artery posterior circumflex humeral artery and the circumflex scapular artery
Nerve axillary nerve
Actions laterally rotates the arm, adducts the forearm, stabilizes humerus

Front 25

Teres Major

Back 25

Origin -posterior aspect of the inferior angle of the scapula
Insertion - medial lip of the intertubercular sulcus of the humerus

Artery - Subscapular and circumflex scapular arteries
Nerve - Lower subscapular nerve (segmental levels C6 and C7)
Actions - Internal rotation (medial rotation) of the humerus

Front 26

Deltoid

Back 26

Origin the anterior border and upper surface of the lateral third of the clavicle, acromion, spine of the scapula
Insertion deltoid tuberosity of humerus
Artery primarily posterior circumflex humeral artery
Nerve Axillary nerve
Actions shoulder abduction ( 15 -90), flexion and extension

Front 27

Serratus Anterior

Back 27

Origin fleshy slips from the outer surface of upper 8 or 9 ribs
Insertion costal aspect of medial margin of the scapula
Artery lateral thoracic artery (upper part), thoracodorsal artery (lower part)
Nerve long thoracic nerve (from roots of brachial plexus C5, 6, 7)
Actions - protracts and stabilizes scapula, assists in upward rotation. abduct humerus (above 90)