Overview
A broad, flat muscle caudal to the scapula. Its fibres converge cranioventrally, pass medial to the long head of the triceps and end in a tendon shared with the teres major.
Origin
Thoracolumbar fascia, which attaches it to the spinous processes of the caudal thoracic and lumbar vertebrae.
Insertion
Teres major tuberosity (tuberositas teres major) on the medial surface of the humerus.
Action
Flexes the shoulder and draws the limb caudally. With the limb planted, it pulls the trunk cranially.
Innervation
Thoracodorsal nerve (n. thoracodorsalis).