I'm sure you know that Adductor pollicis is often used for neuromuscular monitoring (train of four etc.) with stimulation of the ulnar nerve. It is used to monitor the level of neuromuscular block as well as to know adequate reversal after reversal drugs like neostigmine. Let me tell you about Fromet's sign. Froment's sign is a special test of the wrist for palsy of the ulnar nerve, specifically, the action of adductor pollicis.

The Froment sign correlates with the complaint of a weakened ability to pinch normally between the first and second digits. This sign is sometimes elicited by asking the patient to grasp a piece of paper between the thumb and the index finger.