Muscles of the Shoulder

Question 1

Deltoid

Answer 1

O: lateral third of clavicle + acromion + spine of scapula

I: deltoid tuberosity on shaft of humerus

A: abduction, flexion, medial rotation, lateral rotation, and extension of the arm

In: axillary nerve

Question 2

Teres Major

Answer 2

O: inferior angle of scapula

I: medial lip of intertubercular groove of humerus

A: adduction, medial rotation, and extension of the arm

In: lower subscapular nerve