Lateral view, right side
origin: anterosuperior border of the lateral
half of the clavicle, acromion and spine
of the scapula
insertion: deltoid tuberosity of humerus
nerve: axillary (C5, C6)
action: anterior division: horizontal adductor,
prime flexor, and medial (internal) rotation
of shoulder (arm)
middle division: abducts shoulder (arm)
posterior division: abducts (horizontal
abduction), laterally (externally) rotates
and extends shoulder (humerus or arm)
This is one of the five muscles in the group we refer to as the muscles that move the arm (not including the rotator cuff muscles).
2008 by William C. Johnson II
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