Radius (bone)
The radius was a bone in the Humanoid skeletal system. Together with the ulna, it formed the bone structure of the forearm. 

When solanogen-based lifeforms conducted experiments on Commander William T. Riker in 2369, they severed his forearm. When reattaching the arm, they created an offset of 0.2 microns, visible in a scan of the bone structure of his ulna and radius. ()

After having  with Grilka in 2373, Quark had a compound fracture of the right radius, two fractured ribs, torn ligaments, strained tendons and several bruises, contusions and scratches. ()

The ChoH'a' Species reassignment protocol involved shortening the radius. ()

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Bones