The thoracodorsal nerve, also known as the long subscapular or middle subscapular nerve, is a pure motor nerve originating from spinal nerve roots C6 through C8, exiting the brachial plexus after branching off the posterior cord. It then travels inferiorly down the posterior axillary wall, passing under the inferior edge of the teres major muscle and ultimately innervating the latissimus dorsi muscle (name meaning “broadest back” in Latin), aiding in adduction, medial rotation, and extension of the arm at the elbow.