Axillary Arch of Langer
Shoulder & Arm
A common accessory muscle slip crossing the axilla, found in about 7% of people — can compress the axillary artery, vein, or brachial plexus and cause symptoms.
Function
May assist adduction; can compress axillary vessels/nerves
Origin
Usually latissimus dorsi border
Insertion
Pectoralis major tendon, coracobrachialis fascia, or humerus
Innervation
Usually thoracodorsal nerve, variable