Flexors of the Shoulder

Question 1

Pectoralis Major

Answer 1

O: medial half of anterior surface of the clavicle and the lateral aspect of the body of the sternum
I: into the lateral lip of the intertubercular groove of the humerus
N: Medial C8 & Lateral C5, C6, C7 pectoral nerves
A: Medial rotation and adduction of the shoulder joint.
Clavicular part - shoulder flexion
sternal part - shoulder extension from a flexed position

Question 2

Deltoid

Answer 2

O:
Anterior Fibres - Lateral 1/3 of the anterior aspect of the clavicle.
Middle fibres - lateral aspect of the acromion of the scapula
Posterior fibres - lateral 1/3 of the lower aspect of the spine of the scapula
I: Delotid tuberosity of the humerus
N: Axillary Nerve C5, C6
A:
Anterior fibres - flexion of the shoulder
Middle fibres - abduction of the shoulder
Posterior fibres - extension of the shoulder

Question 3

Corcacobrachialis

Answer 3

O: coracoid process of the scapula
I: medial side of the shaft of the humerus, approx. 1/3 of the way down the shaft
N: Musculocutaneous nerve C6, C7
A: Flexion & adduction of the shoulder joint

Question 4

Biceps Brachii (Long Head)

Answer 4

O:
Long head - superior glenoid tubercle of the scapula
Short head - coracoid process of the scapula
I: bicipital aponeurosis and the radial tuberosity
N: musculocutaneous nerve C5, C6
A:
Long head - flexion of the shoulder joint
Long head & short head - flexion and supination of the elbow