SHOULDER COMPLEX

RETRACTORS

Middle trapezius, rhomboids, lower trapezius.

PROTRACTORS

Protractor: Serratus anterior.

ELEVATORS

Upper trapezius, levator scapulae, rhomboids.

DEPRESSORS

Lower trapezius, latissimus dorsi, pectoralis major, subclavius.

Flexors

Clavicular head of pectoralis major, anterior deltoid, coracobrachialis, and biceps brachii.

Abductors

Supraspinatus, anterior deltoid, middle deltoid.

Adductors

Latissimus dorsi, teres major, pectoralis major (sternocostal head).

External Rotators

Infraspinatus, teres minor, posterior deltoid.

Internal Rotators

Subscapularis, teres major, latissimus dorsi, pectoralis major.

Extensors

Latissimus dorsi, posterior deltoid, teres major, long head of triceps brachii, sternocostal head of the pectoralis major.

· Mnemonic is the action of the latissimus dorsi at the glenohumeral joint.

ExAd.ir

Upward Rotators

Upper trapezius, serratus anterior, lower trapezius.

Downward Rotators

Rhomboids, levator scapulae, pectoralis minor.

middle trapezius

  · Origin: C7-14

  · Insertion: Acromion and Spine of scapula

  · Nerve: Spinal part of accessory nerve (motor), C3 & C4 (sensory)

  · Action: Retracts and rotates the pectoral girdle at AC and SC joints. Pulls the scapula medially.

rhomboid major

  · Origin: Spine of T2-T5

  · Insertion: Medial Border of scapula

  · Nerve: Dorsal scapular nerve

  · Action: Retracts and downwardly rotates shoulder at the AC and SC joints. Raises medial border of scapula upward and medially.

rhomboid minor

  · Origin: Ligamentum nuchae and spinous of C7 and T1

  · Insertion: Medial border of scapula

  · Nerve: Dorsal scapular nerve (C4-C5)

  · Action: Retracts and downwardly rotates shoulder at AC and SC joints.

lower trapezius

  · Origin: Spinous process of T5-T12

  · Insertion: Medial end of spine of scapula

  · Nerve: Accessory nerve anterior rami of C3-C4

  · Action: Depresses, retracts, and upwardly rotates the shoulder at AC and SC joints.

serratus anterior

  · Origin: External surfaces of 1st - 9th rib

  · Insertion: Medial border of scapula

  · Nerve: Long thoracic nerve (C5-C7)

  · Action: Protracts and upwardly rotates shoulder at AC and SC joints.

upper trapezius

  · Origin: Occipital bone, nuchal ligament, and spinous process of C7

  · Insertion: Acromion and Spine of scapula

  · Nerve: Accessory nerve, anterior rami of C3-C4

  · Action: Elevates, retracts, and upwardly rotates the shoulder at AC and SC joints. Extends and laterally flexes head and neck.

levator scapulae

  · Origin: Transverse process of C1-C4

  · Insertion: Medial border of scapula

  · Nerve: C3-C4 and dorsal scapular nerve

  · Action: Elevates and downwardly rotates shoulder at AC and SC joints. Extends and laterally flexes neck and cervical vertebral joints.

anterior deltoid

  · Origin: Lateral third of clavicle, Acromion, Spine of scapula

  · Insertion: Deltoid tuberosity of humerus

  · Nerve: Axillary nerve (C5-C6)

  · Action: Abducts arm at GH joint. Anterior fibers flex and medially rotate arm. Posterior fibers extend and laterally rotate arm.

coracobrachialis

  · Origin: Coracoid process of scapula

  · Insertion: Middle third of medial aspect of humerus

  · Nerve: Musculocutaneous nerve

  · Action: Adducts and flexes arm at GH joint.

biceps brachii

  · Origin: Long Head: Supraglenoid tubercle of scapula; Short Head: Coracoid process of scapula

  · Insertion: Tuberosity of radius and bicipital aponeurosis into deep fascia of arm

  · Nerve: Musculocutaneous nerve (C5-C6)

  · Action: Supinator of forearm, Elbow Joint Flexor, Weak shoulder joint flexor.

supraspinatus

  · Origin: Supraspinous fossa of scapula

  · Insertion: Greater tuberosity of humerus, Capsule of shoulder joint

  · Nerve: Suprascapular nerve

  · Action: Abducts arm and stabilizes shoulder joint.

middle deltoid

  · Origin: Lateral third of clavicle, Acromion, Spine of scapula

  · Insertion: Deltoid tuberosity of humerus

  · Nerve: Axillary nerve (C5-C6)

  · Action: Abducts arm at GH joint.

infraspinatus

  · Origin: Infraspinous fossa of scapula

  · Insertion: Greater tuberosity of humerus, Capsule of shoulder joint

  · Nerve: Suprascapular nerve

  · Action: Laterally rotates arm and stabilizes shoulder joint.

teres minor

  · Origin: Upper 2/3 of lateral border of scapula

  · Insertion: Greater tuberosity of humerus, Capsule of shoulder joint

  · Nerve: Axillary nerve

  · Action: Laterally rotates arm and stabilizes shoulder joint.

subscapularis

  · Origin: Subscapular fossa

  · Insertion: Lesser tuberosity of humerus

  · Nerve: Upper and lower subscapular nerves

  · Action: Medially rotates arm and stabilizes shoulder joint.

teres major

  · Origin: Posterior inferior angle of scapula

  · Insertion: Crest of lesser tubercle of humerus

  · Nerve: Lower subscapular nerve (C5-C7)

  · Action: Adducts and medially rotates arm at GH joint.

latissimus dorsi

  · Origin: Iliac crest, Lumbar fascia, Spines of L1-L5, Spinous process of T7-T12, 9th-12th rib

  · Insertion: Floor of bicipital groove of humerus

  · Nerve: Thoracodorsal nerve (C6-C8)

  · Action: Extends, adducts, and rotates the arm medially at GH joint.

pectoralis major

  · Origin: Clavicle, Sternum, and upper 6 costal cartilages

  · Insertion: Lateral lip of intertubercular groove

  · Nerve: Medial and Lateral Pectoral nerve

  · Action: Flexes, shoulder, adducts and medially rotates arm, and extends shoulder from flexed position.

posterior deltoid

  · Origin: Lateral third of clavicle, Acromion, Spine of scapula

  · Insertion: Deltoid tuberosity of humerus

  · Nerve: Axillary nerve (C5-C6)

  · Action: Abducts arm at GH joint. Posterior fibers extend and laterally rotate arm.

triceps brachii long head

  · Origin: Infraglenoid tubercle of scapula

  · Insertion: Olecranon process of ulna

  · Nerve: Radial nerve

  · Action: Extends elbow, extends shoulder.

pectoralis minor

  · Origin: 3rd-5th rib

  · Insertion: Coracoid process of scapula

  · Nerve: Medial and lateral pectoral nerves (C5-T1)

  · Action: Protracts and downwardly rotates shoulder at AC and SC joints.

subclavius

  · Origin: Sup. surface of costal end of first rib, Adjacent first costal cartilage

  · Insertion: Inf. surface of the middle 1/3 of clavicle

  · Nerve: Nerve to subclavius from upper trunk of brachial plexus

  · Action: Stabilizes and depresses clavicle.

triceps brachii (lateral head)

  · Origin: Upper half of posterior surface of shaft of humerus

  · Insertion: Olecranon process of the ulna

  · Nerve: Radial

  · Action: Extensor of elbow joint

triceps brachii (medial head)

  · Origin: Lower half of posterior surface of shaft of humerus

  · Insertion: Olecranon process of the ulna

  · Nerve: Radial

  · Action: Extensor of elbow joint