Claim: Thumbs are innervated by the superficial fibular nerve, and the flexor digitorum brevis originates on the ventral side of the fibula.
Evidence: It is innervated by the anterior interosseus branch of the median nerve (C7-C8) It is a persistence of one of the former contrahentes muscles that pulled the fingers or toes together. Dorsal digital nerves of radial nerve, proper palmar digital nerves of median nerve