Muscles of the Shoulder and Pectoral Region Flashcards
Muscles moving the arm: PECTORALIS MAJOR
Origin: 2 head origins
Clavicular head - anterior surface of medial 1/2 clavicle
Sternocostal head - anterior surface of sternum, first 7 costal cartilages, sternal end of 6th rib, aponeurosis of external obliques
Insertion: lateral lip of intertubercular sulcus of humerus
Innervation: lateral & medial pectoral nerves
Action: flexion, adduction, medial rotation of arm
Muscles moving the arm: LATISSIMUS DORSI
Origin: spinous processes of T7-T12 + interspinous ligaments, thoracolumbar fascia to spinous processes of L1-L5 + interspinous ligaments, iliac crest, and lower 3-4 ribs
Insertion: floor of intertubercular sulcus
Innervation: thoracodorsal nerve
Action: adduction, medial rotation, extension of arm @ shoulder
Muscles moving the arm: DELTOID
Origin: inferior edge of spine of scapula, acromion, anterior border of lateral 1/3 of clavicle
Insertion: deltoid tuberosity of humerus
Innervation: axillary nerve
Action: abduction, flexion, extension, and medial & lateral rotation of arm @ shoulder
Muscles moving the arm: SUPRASPINATUS
Origin: supraspinatus fossa
Insertion: superior facet of greater tubercle of humerus
Innervation: suprascapular nerve
Action: abduction of arm (RC)
Muscles moving the arm: INFRASPINATUS
Origin: infraspinatus fossa
Insertion: middle facet of greater tubercle of humerus
Innervation: suprascapular nerve
Action: lateral rotation of arm (RC)
Muscles moving the arm: TERES MAJOR
Origin: inferior angle of scapula
Insertion: medial lip of intertubercular sulcus
Innervation: inferior suprascapular nerve
Action: medial rotation and extension of arm
Muscles moving the arm: TERES MINOR
Origin: upper 2/3 of lateral border of scapula
Insertion: inferior facet of greater tubercle of humerus
Innervation: axillary nerve
Action: lateral rotation of arm (RC)
Muscles moving the arm: SUBSCAPULARIS
Origin: subscapular fossa
Insertion: lesser tubercle of humerus
Innervation: upper & lower subscapular nerves
Action: medial rotation of arm (RC)
Muscles moving the shoulder: SERRATUS ANTERIOR
Origin: lateral surfaces of ribs 1-8/9
Insertion: costal surface on medial border of scapula
Innervation: long thoracic nerve
Action: protraction and rotation of scapula
Muscles moving the shoulder: PECTORALIS MINOR
Origin: anterior surface of ribs 3-5
Insertion: coracoid process
Innervation: medial pectoral nerve
Action: stabilises and protracts scapula
Muscles moving the shoulder: LEVATOR SCAPULAE
Origin: transverse processes C1-4
Insertion: medial border of scapular from superior angle to root of spine
Innervation: dorsal scapular nerve, C3-4
Action: elevates scapular
Muscles moving the shoulder: RHOMBOID MAJOR
Origin: spinous processes T2-5
Insertion: medial border of scapular from spine root to inferior angle
Innervation: dorsal scapular nerve
Action: elevates and retracts scapula
Muscles moving the shoulder: RHOMBOID MINOR
Origin: ligamentum nuchae and spinous processes C7-T1
Insertion: medial border at root of spine
Innervation: dorsal scapular nerve
Action: elevates and retracts scapula
Muscles moving the shoulder: TRAPEZIUS
Origin: superior nuchal line, external occipital protuberance, ligamentum nuchae, spinous processes of C7-T1, and supraspinous ligaments
Insertion: superior edge of spine of scapula, acromion, posterior border of lateral 1/3 of clavicle
Innervation: accessory nerve (CN11) and C3-4
Action: elevate, depress, retract and rotate scapula
Muscles moving the shoulder: SUBCLAVIUS
Origin: rib at 1st costalchondral junction
Insertion: groove on inferior surface of middle 1/3 of clavicle
Innervation: nerve to subclavius
Action: pulls clavicle medially for stabilisation
