The ulnar collateral ligament (UCL) or internal lateral ligament is a thick triangular ligament at the medial aspect of the elbow uniting the distal aspect of the humerus to the proximal aspect of the ulna.
The posterior portion, also of triangular form, is attached, above, by its apex, to the lower and back part of the medial epicondyle; below, to the medial margin of the olecranon.
Between these two bands a few intermediate fibers descend from the medial epicondyle to blend with a transverse band which bridges across the notch between the olecranon and the coronoid process.
During activities such as overhand baseball pitching, this ligament is subjected to extreme tension, which places the overhand-throwing athlete at risk for injury.[4] Acute or chronic disruption and/or attenuation of the ulnar collateral ligament often result in medial elbow pain, valgus instability, and impaired throwing performance. There are both non-surgical and surgical treatment options.[5]
Additional images
Elbow joint. Deep dissection. Anterior view.
Elbow joint. Deep dissection. Anterior view.
Anatomy of the ulnar collateral ligament in the pitcher's elbow