The axillary arch is a variant muscular slip of
this muscle and is about 7 to 10 cm in length, splits from
the upper edge of the latissimus dorsi and crosses the
axilla in front of the axillary vessels and nerves.
This variant muscle slip joins inferiorly to the tendon of the
pectoralis major, the coracobrachialis or the fascia over
the biceps brachii.