Ligament of Struthers. X-ray photograph of the elbow showing the Ligament of Struthers. It is seen attached to the humerus (upper arm bone at top right, right X-ray), and the medial epicondyle (bony projection at centre left, left X-ray). The Ligament of Struthers is a fibrous band connecting the lowest attachment of the coracobrachialis muscle on the humerus with the medial epicondyle (bony projection at the end of the humerus). This ligament is very rare. If it is present, it will prevent the arm from straightening.