Upper Limb Flashcards
Deltoid
Origin : lateral third of clavicle, acromion, spine of scapula
Insertion : deltoid tuberosity of humerus
Innervation : axillary nerve (*C5, C6)
Action : clavicular (anterior) - flexes and medially rotates shoulder joint
acromial (middle) - abducts shoulder joint
spine (posterior) - extends and laterally rotates shoulder joint
Supraspinatus
Origin : Supraspinous fossa of scapula
Insertion : superior facet of greater tubercle of humerus
Innervation: suprascapular nerve (C4,*C5,C6)
Action : initiates and assists deltoid in abduction of shoulder joint and acts with other rotator cuff muscles
Infraspinatus
Origin : infraspinous fossa of scapula
Insertion : middle facet of greater tubercle of humerus
Innervation : suprascapular nerve (*C5, C6)
Action : laterally rotates shoulder joint; help hold humeral head in glenoid cavity of scapula
Teres minor
Origin : middle part of lateral border of scapula
Insertion : inferior facet of greater tubercle of humerus
Innervation : axillary nerve (*C5, C6)
Action : laterally rotate shoulder joint; help hold humerus head in glenoid cavity of scapula
Teres major
Origin : inferior part of lateral border of scapula and posterior surface of inferior angle of scapula
Insertion: medial lip of intertubercular sulcus of humerus
Innervation: lower subscapular nerve (C5, *C6)
Action : adducts and medially rotates shoulder joint
Subscapularis
Origin : subscapular fossa (most of anterior surface of scapula)
Insertion : lesser tubercle of humerus
Innervation : upper and lower subscapular nerves (C5,*C6,C7)
Action : medially rotates and adducts shoulder joint; helps hold humeral head in glenoid cavity
Pectoralis major
Proximal attachment:
Clavicular head - anterior surface of medial half of clavicle
Sternocostal head - anterior surface of sternum, superior six costal cartilages, aponeurosis of external oblique muscle
Distal attachment :
Lateral lip of intertubercular sulcus of humerus
Innervation: lateral and medial pectoral nerves, clavicular head (C6), sternocostal head (C7, C8)
Action : adducts and medially rotates shoulder joint, draws scapula anteriorly and inferiorly
Acting alone, clavicular head flexes shoulder joint and the sternocostal head extends it from the fixed position
Pectoralis minor
Proximal attachment : 3rd and 5th ribs near their costal cartilages
Distal attachment : medial border and superior surface of coracoid process of scapula
Innervation: medial pectoral nerve (C8,T1)
Action : stabilizes scapula by drawing inferiorly and anteriorly against thoracic wall
Subclavius
Proximal attachment : junction of 1st rib and its costal cartilage
Distal attachment : inferior surface of middle third of clavicle
Innervation : subclavian nerve (C5)
Action : anchors and depresses scapula
Serratus anterior
Proximal attachment : external surfaces of lateral parts of 1st-8th ribs
Distal attachment : anterior surface of medial border of scapula
Innervation: long thoracic nerve (C6, C7)
Action : protracts scapula and holds against thoracic wall; rotates scapula
Dorsal scapular (C4, *C5)
Rhomboids and occasionally levator scapulae
Long thoracic (*C5, *C6,C7)
Serratus anterior
Suprascapular (*C5, C6, and often C4)
Supraspinatus, infraspinatus, glenohumeral joint
Subclavian nerve (C4, C5, *C6)
Subclavius and sternoclavicular (SC) joint
Lateral pector (C5, *C6, C7)
Primarily pectoralis major but some lateral fibers pass to pectoralis minor