Hoffmann's reflex / Finger flexor reflex

 Hoffmann's reflex / The finger flexor reflex ranks among physiological myotatic (proprioceptive) reflexes on the upper limb with C8 segmental innervation.

flick the patient's nail of the middle finger with your thumb. The test is positive if you're able to observe quick adduction of the thumb 👍 and flexion of the index ☝️ finger