Oblique cord
The oblique cord is a small ligament in the forearm near the elbow that connects the ulna to the radius. It runs diagonally from the base of the ulna near the coronoid process to a point just below the radius’s tuberosity, with fibers that go in the opposite direction to the interosseous membrane.
Size and appearance vary. On average it is about 3.4 cm long, but it can be a rounded cord or a flat membrane. It is not present in every person and can be absent in a noticeable number of arms.
It is found in most humans and many other primates, but not in some New World monkeys.
Function is not clear. It may act as an extra connection between the two bones and help nearby structures, possibly limiting extreme forward movement of the radius. It does not seem to be crucial for forearm stability, rotation, or preventing bone buckling, and some researchers think it might be a vestigial remnant from our evolutionary past.
This page was last edited on 2 February 2026, at 09:24 (CET).