Claw hand is caused by lesion of (DNB Dec 2011)
a. Claw hand: hyperextension at the metacarpo phalangeal joint and flexion at proximal and distal inter phalangeal joint.
b. This occurs due to paralysis of lumbricals which flex the MCP and extend the interphalangeal joint.
c. Low Ulnar nerve injury causes more marked claw hand because it spares the flexors of the fingers.
d. Complete claw hand occurs due to combined paralysis of Ulnar and Median nerve.