Question:medium
Froment's sign is positive in cases of weakness of?
Froment's sign is positive in cases of weakness of?
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It signals ulnar nerve palsy, paralysing the adductor pollicis so the thumb flexes to grip.
Updated On: Jun 24, 2026
- Thumb adduction
- Thumb abduction
- Thumb flexion
- Thumb extension
Show Solution
The Correct Option is A
Solution and Explanation
Step 1: The adductor pollicis pulls the thumb toward the palm and is one of the small hand muscles run by the ulnar nerve. Froment's sign is simply a clinical way of catching its failure.
Step 2: Ask the person to clamp a piece of paper between thumb and the radial border of the index finger and then tug it. A healthy adductor pollicis keeps the thumb straight while gripping.
Step 3: When the ulnar nerve is out of action, this adductor cannot generate the pinch. The brain recruits the flexor pollicis longus, which is fed by the median nerve, to do the job instead.
Step 4: That substitution bends the tip of the thumb at the IP joint, and this tell-tale flexion is the positive test. So the underlying weakness lies in adduction of the thumb.
\[\boxed{\text{Thumb adduction (ulnar nerve / adductor pollicis)}}\]
Step 2: Ask the person to clamp a piece of paper between thumb and the radial border of the index finger and then tug it. A healthy adductor pollicis keeps the thumb straight while gripping.
Step 3: When the ulnar nerve is out of action, this adductor cannot generate the pinch. The brain recruits the flexor pollicis longus, which is fed by the median nerve, to do the job instead.
Step 4: That substitution bends the tip of the thumb at the IP joint, and this tell-tale flexion is the positive test. So the underlying weakness lies in adduction of the thumb.
\[\boxed{\text{Thumb adduction (ulnar nerve / adductor pollicis)}}\]
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