What does Hoffman’s Reflex involve?

Hoffman’s Reflex is a specialized neurological response that involves the palmar flexion of the thumb, which occurs following the stimulation of the distal phalanx of the index finger. This reflex is often utilized in clinical settings as a test for upper motor neuron dysfunction, particularly in conditions affecting the corticospinal pathways. The response is indicative of the integrity of the nervous system's reflex arcs and can help in diagnosing neurological conditions.

The other options do not accurately describe Hoffman’s Reflex. For instance, flexion of the leg when the foot is tapped relates more to other reflexes such as the patellar reflex. Inflation of the lungs upon stimulation is not a reflex and is unrelated to Hoffman’s reflex. Finally, extension of the arm after a flexed arm test is a different phenomenon, not associated with the specific response of Hoffman’s Reflex.