Anatom3DUlnar collateral ligament
Ligamentum collaterale ulnare · Loketní postranní vaz lokte
Joints & cartilage
Looks like
A triangular band on the inner side of the elbow, from the inner bump of the arm bone to the ulna.
What it does
The main restraint against the elbow opening on the inner side when throwing.
Keeping it well
Torn in throwing athletes; reconstruction is the 'Tommy John' operation. The ulnar nerve runs just behind it.