Which of the following DOES NOT indicate ulnar nerve injury?
High-Yield Explanation
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.