Superficial back, trunk, and shoulder muscles OIA

What is the origin of the trapezius

• superior nuchal line

• external occipital protuberance

• ligamentum nuchae

• spinous processes of C7 - T12

What is the insertion of the trapezius

• lateral 1/3 of clavicle

• acromion

• spine of scapula

What is the action of the trapezius

• rotate scapula during abduction of humerus above horizontal

• upper fibers elevate, middle fibers adduct, lower fibers depress scapula

What is the origin of the latissimus dorsi

• spinous processes of T7 - L5

• sacrum

• iliac crest

• ribs 10-12

What is the insertion of the latissimus dorsi

• floor of intertubercular sulcus of humerus

What is the action of the latissimus dorsi

• extends, adducts, and medially rotates humerus

What is the origin of the levator scapulae

Transverse processes of C1 - C4

What is the insertion of the levator scapulae

upper portion of medial border of scapula

What is the action of the levator scapulae

elevates scapula

What is the origin of the rhomboids

• spinous processes of T2 - T5

• lower portion of ligamentum nuchae

• spinous processes of C7 and T1

what is the insertion of the rhomboids

• medial border of scapula between spine and inferior angle

• medial border of scapula at the spine of the scapula

what is the action of the rhomboids

retracts (adducts) and elevates scapula

what is the origin of the deltoid

• inferior edge of crest of spine of scapula

• lateral margin of acromion

• anterior border of lateral 1/3 of clavicle

what is the insertion of the deltoid

• deltoid tuberosity of humerus

what is the action of the deltoid

• major abductor of arm

• clavicular fibers assist in flexing arm

• posterior fibers assist in extending arm

what is the origin of the pectoralis major

• medial half of the clavicle

• anterior surface of sternum

• 1st 7 coastal cartilages

• aponeurosis of external oblique

what is the insertion of the pectoralis major

• lateral lip of intertubercular sulcus of humerus

what is the action of the pectoralis major

• adduction, medial rotation, and flexion of humerus at shoulder joint

what is the origin of the pectoralis minor

• anterior surfaces of 3rd, 4th, 5th ribs

• deep fascia overlying related intercostal spaces

what is the insertion of the pectoralis minor

coracoid process of scapula

what is the action of the pectoralis minor

• depresses tip of shoulder

• protracts scapula

what is the origin of the serratus anterior

• lateral surfaces of upper 8-9 ribs

• deep fascia overlying the related intercostal spaces

what is the insertion of the serratus anterior

• costal surface of medial border of scapula

what is the action of the serratus interior

• protraction and rotation of scapula

• keeps medial border and inferior of scapula opposed to thoracic wall

what is the origin of the erector spinae

• sacrum

• spinous process of lumar and thoracic vertebrae and their supraspinous ligaments

• iliac crest

• angles of ribs

• lower part of ligamentum nuchae

• transverse process of lumbar and thoracic vertebrae

• articular proceesses of cervicle vertebrae

what is the insertion of the erector spinae

• angles of ribs

• transverse processes of cervical vertebrae

• transverse process of thoracic vertebrae

• posterior margin of mastoid process

• spinous process of thoracic vertebrae

• spinous process of cervical vertebrae

what is the action of the erector spinae

• primary extensors of vertebral column and head

• acting bilaterally, straighten back returning to upright position from flexed position

• pull head posteriorly

• control vertebral column flexion

• acting unilaterally, bend vertebral column laterally and turn heaad to actively contracting side

what is the origin of the splenius capitis

• lower ½ of ligamentum nuchae

• spinous processes of C7 - T4

what is the insertion of the splenius capitis

• mastoid process

• skull below lateral 1/3 of superior nuchal line

what is the action of the splenius capitis

• together, draw head backward

• individually, draw hand rotate head to one side (turn face to same side)

what is the origin of the semispinalis capitis

• transverse processes of T1 - T6 or 7 and C7

• articular processes of C4 - C6

what is the insertion of the semispinalis capitis

• medial area between superior and inferior nuchal lines of occipital bone

what is the action of the semispinalis capitis

• contracting bilaterally, pulls head posteriorly

• contracting unilaterally, pulls head posteriorly and turns it, moving chin superiorly and turning towards side of contracting muscle

trapezius innervation

• motor - accessory nerve (CN 11)

• proprioception - C3 + C4

latissimus dorsi innervation

• Thoracodorsal nere (C6-C8)

levator scapulae innervation

• C3 to C4 and dorsal scapular nerve (C4, C5)

rhomboid innervation

• dorsal scapular nerve (C4, C5)

deltoid innervation

• axillary nerve [C5, C6]

pectoralis major innervation

• medial and lateral pectoral nerves

pectoralis minor innervation

• medial pectoral nerves

serratus anterior innervation

• long thoracic nerve [C5, C6, C7]

erector spinae innervation

segmental brances of posterior rami of spinal nerves

splenius capitis innervation

• posterior rami of middle cervical nerves

semispinalis capitis innervation

• 3rd occipital nerve (branch of posterior ramus of C3 spinal nerve