Week 2 Muscle Charts

Trapezius origin

Superior nuchal line, external occipital protuberance, ligamentum nuchae, spinous processes of C7 to T12

Trapezius insertion

Clavicle, acromion, spine of scapula

Trapezius action

Upper fibers elevate and upwardly rotate, middle fibers adduct, and lower fibers depress scapula

Trapezius innervation

Spinal accessory nerve (CN 11); anterior rami C3 and C4

Deltoid origin

Spine of the scapula, acromion, and clavicle

Deltoid insertion

Deltoid tuberosity of the humerus

Deltoid action

Middle fibers: Abduction of arm, Anterior fibers: flexion of the arm; Posterior fibers: extension of the arm

Deltoid innervation

Axillary n. [C5,C6]

Rhomboid major origin

Spinous processes of T2-T5 vertebrae

Rhomboid major insertion

Medial border of scapula from the root of the spine of the scapula to the inferior angle

Rhomboid major action

Retraction (adduction), elevation and downward rotation of scapula

Rhomboid major innervation

Dorsal scapular n. [C5]

Rhomboid minor origin

Lower portion of ligamentum nuchae, spinous processes of C7 and T1

Rhomboid minor insertion

Root of the spine of the scapula

Rhomboid minor action

Retraction (adduction), elevation and downward rotation of scapula

Rhomboid minor innervation

Dorsal scapular n. [C5]

Serratus anterior origin

Lateral surface of upper 8 or 9 ribs

Serratus anterior insertion

Medial border of the scapula

Serratus anterior action

Protraction; keeps medial border of scapula opposed to thoracic wall, scapular upward rotation

Serratus anterior innervation

Long thoracic n. [C5,C6,C7]

Levator scapulae origin

Transverse processes of C1 to C4

Levator scapulae insertion

Superior angle of the scapula

Levator scapulae action

Elevation and downward rotation of the scapula

Levator scapulae innervation

Dorsal scapular nerve [C5]; anterior rami C3 and C4;

Pectoralis minor origin

Ribs 3 to 5

Pectoralis minor insertion

Coracoid process of the scapula

Pectoralis minor action

Pulls tip of shoulder down; protracts scapula; downward rotation of scapula

Pectoralis minor innervation

Medial pectoral n. [C8-T1]

Subclavius origin

First rib

Subclavius insertion

Clavicle

Subclavius action

Pulls clavicle medially to stabilize sternoclavicular joint

Subclavius innervation

Nerve to the subclavius [C5, C6]

Supraspinatus origin

Supraspinous fossa

Supraspinatus insertion

Greater tubercle of the humerus

Supraspinatus action

Abduction of arm (Primarily first 15 degrees)

Supraspinatus innervation

Suprascapular n. [C5,C6]

Infraspinatus origin

Infraspinous fossa

Infraspinatus insertion

Greater tubercle of the humerus

Infraspinatus action

Lateral rotation of arm at the glenohumeral joint

Infraspinatus innervation

Suprascapular n. [C5,C6]

Teres minor origin

Lateral border of the scapula

Teres minor insertion

Greater tubercle of the humerus

Teres minor action

Lateral rotation of arm at the glenohumeral joint

Teres minor innervation

Axillary n. [C5,C6]

Subscapularis origin

Subscapular fossa

Subscapularis insertion

Lesser tubercle of humerus

Subscapularis action

Medial rotation of arm at the glenohumeral joint

Subscapularis innervation

Upper and lower subscapular nn. [C5,C6]

Teres major origin

Inferior angle of the scapula

Teres major insertion

Medial lip of the intertubercular sulcus

Teres major action

Medial rotation of arm at the glenohumeral joint

Teres major innervation

Inferior subscapular n. [C5, C6]

Latissimus dorsi origin

Spinous processes of T6 to L5 and sacrum, iliac crest, ribs 10 to 12

Latissimus dorsi insertion

Medial lip of the intertubercular sulcus

Latissimus dorsi action

Extends, adducts, and medially rotates humerus, downward rotation of scapula

Latissimus dorsi innervation

Thoracodorsal n. [C6,C7,C8]

Pectoralis major origin

Clavicle; sternum

Pectoralis major insertion

Lateral lip of the intertubercular sulcus

Pectoralis major action

Flexion, adduction, and medial rotation of arm at glenohumeral joint

Pectoralis major innervation

Medial [C8, T1] and lateral pectoral nn. [C5,C6,C7];

Rectus capitis posterior major origin

Spinous process of C2

Rectus capitis posterior major insertion

Occipital bone

Rectus capitis posterior major action

Extension and ipsilateral rotation of head

Rectus capitis posterior major innervation

Dorsal rami C1

Rectus capitis posterior minor origin

Posterior tubercle of C1

Rectus capitis posterior minor insertion

Occipital bone

Rectus capitis posterior minor action

Extension of head

Rectus capitis posterior minor innervation

Dorsal rami C1

Obliquus capitis superior origin

Transverse process of C1

Obliquus capitis superior insertion

Occipital bone

Obliquus capitis superior action

Extension and ipsilateral lateral flexion of head

Obliquus capitis superior innervation

Dorsal rami C1

Obliquus capitis inferior origin

Spinous process of C2

Obliquus capitis inferior insertion

Transverse process of C1

Obliquus capitis inferior action

Ipsilateral rotation of head

Obliquus capitis inferior innervation

Dorsal rami C1

Sternocleidomastoid origin

Manubrium and clavicle

Sternocleidomastoid insertion

Mastoid process

Sternocleidomastoid action

Bilaterally, pulls the head anteriorly, extends head at atlanto-occipital joint, flexion of cervical spine Unilaterally, turns the chin to the opposite side

Sternocleidomastoid innervation

Spinal accessory (CN 11) and APR C2-3

Platysma origin

Fascia covering pectoralis major and deltoid

Platysma insertion

Inferior border of mandible, skin, and subcutaneous tissues

Platysma action

Draws corners of mouth inferiorly and widens it (sadness/fright) Draws skin superiorly when clenching teeth

Platysma innervation

Cervical branch of facial nerve (CN VII)