Ulnar Claw Hand (Claw Hand): this is due to a lesion in the ulnar nerve. The MCP joints are hyperextended for the ring and tiny fingers because of the lack of the 3rd and fourth lumbrical muscles because of a lesion from the deep department with the ulnar nerve. Os Scaphoideum https://www.theorthopaedicandpainpractice.com/what-are-the-different-bones-found-in-my-hand/