A secretary comes to you complaining of pain in her wrists from typing all day. You determine she likely has carpal tunnel syndrome. Which of the following condition would help you determine the diagnosis?: (A) Inability to adduct little finger, (B) Inability to flex distal interphalangeal joint of ring finger, (C) Flattened thenar eminence, (D) Loss of skin sensation of medial one and half fingers
Answer is C. Carpal tunnel contains median nerve and tendons of flexor pollicis longus, flexor digitorum profundus, and flexor digitorum superficialis muscles. It results from injury to median nerve, which supplies the thenar muscle. Thus, injury to this nerve causes flattened thenar eminence. Middle finger has no attachment for adductors. Ulnar nerve innervates: - medial half of flexor digitorum profundus muscle, which allows flexion of DIP joints of ring and little fingers. - skin over medial one and half fingers and adductor pollicis muscle.