Groove For The Ulnar Nerve On The Humerus, Posterior View

Description

Ulnar nerve groove (sulcus nervi ulnaris) lies on the posterior aspect of the distal humerus, immediately posterior to the medial epicondyle and adjacent to the medial border of the olecranon fossa. From this fixed posterior perspective, the shallow channel is seen as a longitudinal depression that tracks inferiorly toward the interval between the medial epicondyle and the olecranon, the bony corridor commonly called the cubital tunnel. The medial epicondyle forms the prominent medial buttress, while the posterior shaft of the humerus rises superiorly, clarifying how little osseous coverage protects the nerve at this level. A small groove, big consequences. Clinically, this is the site of the familiar “funny bone” paresthesia, where minor trauma compresses the ulnar nerve against bone, and it is also a frequent locus of ulnar neuropathy from repetitive elbow flexion, valgus stress in throwing athletes, or osteophytes and scarring after distal humeral injury. Orthopedic and hand surgeons reference this sulcus when planning cubital tunnel release or anterior transposition, since the nerve’s relationship to the medial epicondyle determines where it can subluxate or tether and where iatrogenic injury is most likely during medial approaches to the elbow. The posterior bony landmarks are unambiguous in this lighting and angle, so surface anatomy teaching and operative orientation read the same way. Use this illustration in upper-limb osteology labs, elbow anatomy lectures for medical and PA curricula, and surgical atlases covering cubital tunnel syndrome, distal humerus fracture fixation, and medial epicondyle exposure. It also fits patient-education materials explaining ulnar nerve symptoms radiating to the ring and little fingers after elbow impact or prolonged flexion. Anatomical accuracy verified by SciePro's Medical Advisory Board.