Which of the following DOES NOT indicate ulnar nerve injury?: (A) Clawing of medial 2 digits, (B) Froment sign is present, (C) Abductor Pollicis longus palsy, (D) Loss of sensory supply of medial little finger and medial half of ring finger
Answer is C. Ans. C. Abductor Pollicis longus palsy* The abductor pollicis longus muscle is innervated by the posterior interosseous nerve, which is a continuation of the deep branch of the radial nerve after it passes through the supinator muscle.* Froment's sign tests for palsy of the ulnar nerve, specifically, the action of adductor pollicis. To perform the test, a patient is asked to hold an object, usually a flat object such as a piece of paper, between their thumb and index finger (pinch grip). The examiner then attempts to pull the object out of the subject's hands. A normal individual will be able to maintain a hold on the object without difficulty.* However, with ulnar nerve palsy, the patient will experience difficulty maintaining a hold and will compensate by flexing the FPL (Flexor Pollicis Longus) of the thumb to maintain grip pressure causing a pinching effect.* Injury of the ulnar' nerve at different levels causes varying motor and sensory deficits.