Question | Answer |
Deltoid | O: Lateral one third of the clavicle, acromion and spine of the scapula
I: Deltoid tuberosity of the humerus
N: Axillary C5,6 |
Teres Major | O: Inferior angle and lower one-third of lateral border of scapula
I: Crest of the lesser tubercle of the humerus
N: Lower subscapular C5, 6, 7 |
Supraspinatus | O: Supraspinous fossa of scapula
I: Greater tubercle of humerus
N: Suprascapular C4, 5, 6 |
Infraspinatus | O: Infraspinous fossa of scapula
I: Greater tubercle of humerus
N: Suprascapula C(4), 5, 6 |
Teres Minor | O: Upper 2/3 of lateral border of the scapula
I: Greater tubercle of humerus
N: Axillary C5, 6 |
Subscapularis | O: Subscapular fossa
I: Lesser tubercle of humerus
N: Upper and lower subscapularis C5, 6, 7 |
Serratus Anterior | O: External surfaces of upper eight or nine ribs
I: Anterior surface of medial border of the scapula
N: Long thoracic C5, 6, 7, 8 |
Pectoralis Major | O: Medial 1/2 of clavicle, sternum and cartilage of 1st to 6th ribs
I: Crest of greater tubercle of humerus
N: Lateral pectoral C5, 6, 7 (Upper fibers)
Lateral and medial pectoral C6, 7, 8, T1 (Lower fibers) |
Pectoralis Minor | O: 3rd, 4th, 6th ribs
I: Medial surface of the coracoid process of the scapula
N: Medial pectoral, with fibers from a communicating branch of lateral pectoral C(6), 7, 8, T1 |
Subclavius | O: First rib and cartilage
I: Inferior surface of middle one third of clavicle
N: subclavian C5, 6 |
Biceps Brachii | O: Coracoid process of scapula (short head)
Supraglenoid tubercle of scapula (long head)
I: Tuberosity of the radius and aponeurosis of biceps brachii
N: Musculocutaneous C5, 6 |
All Fibers of the Deltoid Action | Abduct the shoulder |
Anterior Fibers of the Deltoid Action | Flex the shoulder
Medially Rotate the shoulder
Horizontally adduct the shoulder |
Posterior Fibers of the Deltoid Action | Extend the Shoulder
Laterally Rotate the shoulder
Horizontally abduct the shoulder |
Teres Major Action | Extend the shoulder
Adduct the shoulder
Medially rotate the shoulder |
Supraspinatus Action | Abduct the shoulder
Stabilize the head of the humerus in the glenoid cavity |
Infraspinatus Action | Laterally rotate the shoulder
Adduct the shoulder
Stabilize the head of humerus in glenoid cavity |
Teres Minor Action | Laterally rotate the shoulder
Adduct the shoulder
Stabilize the head of the humerus in the glenoid cavity |
Subscapularis Action | Medially rotate the shoulder
Stabilize the head of the humerus in the glenoid cavity |
Serratus Anterior Action | Abduct the scapula
Upwardly rotate the scapula
Depress the scapula
Hold the medial border of the scapula against the rib cage
(May act to elevate thorax during forced inhalation) |
All Fibers Pectoralis Major Action | Adduct the shoulder
Medially rotate the shoulder
Assist to elevate the thorax during forced inhalation (with arm fixed) |
Upper Fibers Pectoralis Major Action | Flex the shoulder
Horizontally adduct the shoulder |
Lower Fibers Pectoralis Major Action | Extend the shoulder |
Pectoralis Minor Action | Depress the scapula
Abduct the scapula
Downwardly rotate the scapula
(assist to elevate the thorax during forced inhalation with scapula fixed) |
Subclavius Action | Depress the clavicle and draw it anteriorly
Elevate the first rib (to assist during inhalation)
Stabilize the sternoclavicular joint |
Biceps Brachii Action | Flex the elbow
Supinate the forearm
Flex the shoulder |
Triceps Brachii Action | Extend the elbow
Long Head Extends and adducts the shoulder |