The omohyoid muscle and fascia: morphology and anomalies.

The omohyoid and sternohyoid muscles are the lateral and medial margins of the primitive sterno-cleido-omo-hyoid muscle, most of which has been replaced by the omohyoid fascia. The lower attachment of the omohyoid muscle is highly variable. It may arise in part anywhere along the normal line of attachment of the omohyoid fascia; that is, from the clavicle, coracoclavicular ligament, coracoid process or superior transverse scapular ligament. A thick muscular attachment to the clavicle could cause confusion during operations employing limited exposure.