Pectoral & Scapula Region. Anterior Axio-appendicular muscles p698 Moore

Name the pectoralis major heads

clavicular sternocostal

Sub-clavius innervation

Nerves to subclavius C5 (main), C6

Sub-clavius action

anchors & depresses clavicle

Pectoralis minor origin

3rd - 5th ribs near their costal cartilages

Pectoralis Major Action

Adducts & medially rotates humerus Draws scapula anteriorly & inferiorly Acting alone, clavicular head flexes humerus & sternocostal head extend it from the flexed position

What anterior axio-appendicular muscles move the pectoral girdle?

pectoralis major pectoralis minor subclavius serrator anterior

What landmarks is the pectoralis minor useful for identifying?

structures in the axilla e.g. axillary artery.

How do you test the pectoralis major sternocostal head?

Abduct arm 90 degrees then adducted against resistance. If acts normally muscle can be seen & palpated

How do you test the pectoralis major clavicular head?

Abduct arm 90 degrees; individual moves arm anteriorly against resistance. If acts normally muscle can be seen & palpated

Pectoralis Major Origin

Clavicular head:Anterior surface of medial half of clavicle Sternocostal head: anterior surface of sternum, superior six costal cartilages, aponeurosis of external oblique muscles

Sub-clavius insertion

Inferior surface of middle third clavicle

Sub-clavius origin

Junction of 1st rib & it's costal cartilage

Pectoralis Major Innervation

Lateral & medial pectoral nerves Clavicular head: C5, C6 (main) Sternocostal head: C7, C8 (main) T1

Pectoralis Major Insertion

Lateral lip of inter tubercular sulcus of humerus

Serratus anterior innervation

Long thoracic nerve C5, C6 (main), C7 (main)

Pectoralis minor innervation

Medial pectoral nerve C8, T1

Serratus anterior action

Protracts scapula & holds it against thoracic wall Rotates scapula

Pectoralis minor action

Stabilises scapula by drawing it inferiorly & anteriorly against thoracic wall

Serratus anterior insertion

anterior surface of medial border of scapula

Serratus anterior origin

external surface of lateral parts of 1st-8th ribs

How do you test the serratus anterior?

hand of outstretch limb is pushed against a wall. if acting normally several digitations of the muscle can be seen & palpated.

Why is the subclavius muscle useful during tug-of-war?

helps resist tendency for clavicle to dislocate at the sternoclaviuclar joint

Pectoralis minor insertion

medial border & superior surface of coracoid process of scapula

Name a movement pectoralis minor is used for

stabilise scapular when stretching the upper limb forward to touch an object just out of reach

What shape is the pectoralis minor?

Trianglular