NCS QUIZ 1 QUESTIONS ANSWERED CORRECTLY LATEST UPDATE 2026
What is NCS? (nerve conduction studies) - Answers A diagnostic test used to assess the function of
nerves
How do NCS work? - Answers Stimulate nerves and record responses
Why do we do NCS? - Answers To identify nerve and muscle disorders
What is CMAP? - Answers Compound muscle action potential
What is SNAP? - Answers Sensory nerve action potential
What does Antidromic (Anti) mean? - Answers Sending impulse in the opposite direction of its natural
pathway
What does Orthodromic (Ortho) mean? - Answers Sending impulse in the same direction of its
natural pathway
What is MUP? - Answers Motor unit potential
What is Latency? - Answers Time it takes for the signal to travel from the stimulation site to the
recording electrode (unit: ms)
What is Duration? - Answers Time from onset to return to baseline (unit: m/s)
What is Amplitude? - Answers Strength of the impulses from the nerve fibers (units: motor - mV,
sensory - uV)
What is Conduction Velocity (CV)? - Answers Speed at which a nerve transmits an impulse (unit: m/s)
What is the CV equation? - Answers CV = distance / (stim 2 - stim 1)
ex: 200mm / (10m/s - 5m/s) = 40 mm/s
Where is G1 for motor median? - Answers APB (abductor pollicis brevis)
Where is G2 for motor median? - Answers 3-4 distal of APB (on the thumb)
Where is GND for motor median? - Answers Back of hand
What is the distance for motor median? - Answers 7 cm
Where is G1 for motor ulnar? - Answers ADM (abductor digiti minimi)
Where is G2 for motor ulnar? - Answers 3-4 cm distal of ADM (on the pinky)
Where is GND for motor ulnar? - Answers Back of hand
What is the distance for motor ulnar? - Answers 7 cm
Where is G1 for sensory median? - Answers Base of 2nd digit (index finger)
Where is G2 for sensory median? - Answers 3-4 distal (on index finger)
Where is GND for sensory median? - Answers Back of hand
What is the distance for sensory median? - Answers 13 cm
Where is G1 for sensory ulnar? - Answers Base of 5th digit (pinky finger)
Where is G2 for sensory ulnar? - Answers 3-4 cm distal (on pinky finger)
Where is GND for sensory ulnar? - Answers Back of hand
What is the distance for sensory ulnar? - Answers 13 cm
What are F waves? - Answers A motor response, measures the time for stim to travel to the anterior
horn cell and back to G1
Why do we measure F waves? - Answers Looks at proximal nerve function
When/where do we measure F waves? - Answers During motor NCS at distal stim site
How do we measure F waves? - Answers Reverse cathode or rotate anode. Collect 6 waveforms
stimming at 2-4 seconds apart
At what intensity do we test F waves? - Answers Supermax
Are F waves variable or consistent in latency and morphology? - Answers Variable
Why do we test the median nerve? - Answers Carpal tunnel syndrome (entrapment of the median
nerve in the carpal tunnel)
Why do we test the ulnar nerve? - Answers Entrapments: elbow - cubital tunnel, wrist - Guyon's canal
syndrome
What is NCS? (nerve conduction studies) - Answers A diagnostic test used to assess the function of
nerves
How do NCS work? - Answers Stimulate nerves and record responses
Why do we do NCS? - Answers To identify nerve and muscle disorders
What is CMAP? - Answers Compound muscle action potential
What is SNAP? - Answers Sensory nerve action potential
What does Antidromic (Anti) mean? - Answers Sending impulse in the opposite direction of its natural
pathway
What does Orthodromic (Ortho) mean? - Answers Sending impulse in the same direction of its
natural pathway
What is MUP? - Answers Motor unit potential
What is Latency? - Answers Time it takes for the signal to travel from the stimulation site to the
recording electrode (unit: ms)
What is Duration? - Answers Time from onset to return to baseline (unit: m/s)
What is Amplitude? - Answers Strength of the impulses from the nerve fibers (units: motor - mV,
sensory - uV)
What is Conduction Velocity (CV)? - Answers Speed at which a nerve transmits an impulse (unit: m/s)
What is the CV equation? - Answers CV = distance / (stim 2 - stim 1)
ex: 200mm / (10m/s - 5m/s) = 40 mm/s
Where is G1 for motor median? - Answers APB (abductor pollicis brevis)
Where is G2 for motor median? - Answers 3-4 distal of APB (on the thumb)
Where is GND for motor median? - Answers Back of hand
What is the distance for motor median? - Answers 7 cm
Where is G1 for motor ulnar? - Answers ADM (abductor digiti minimi)
Where is G2 for motor ulnar? - Answers 3-4 cm distal of ADM (on the pinky)
Where is GND for motor ulnar? - Answers Back of hand
What is the distance for motor ulnar? - Answers 7 cm
Where is G1 for sensory median? - Answers Base of 2nd digit (index finger)
Where is G2 for sensory median? - Answers 3-4 distal (on index finger)
Where is GND for sensory median? - Answers Back of hand
What is the distance for sensory median? - Answers 13 cm
Where is G1 for sensory ulnar? - Answers Base of 5th digit (pinky finger)
Where is G2 for sensory ulnar? - Answers 3-4 cm distal (on pinky finger)
Where is GND for sensory ulnar? - Answers Back of hand
What is the distance for sensory ulnar? - Answers 13 cm
What are F waves? - Answers A motor response, measures the time for stim to travel to the anterior
horn cell and back to G1
Why do we measure F waves? - Answers Looks at proximal nerve function
When/where do we measure F waves? - Answers During motor NCS at distal stim site
How do we measure F waves? - Answers Reverse cathode or rotate anode. Collect 6 waveforms
stimming at 2-4 seconds apart
At what intensity do we test F waves? - Answers Supermax
Are F waves variable or consistent in latency and morphology? - Answers Variable
Why do we test the median nerve? - Answers Carpal tunnel syndrome (entrapment of the median
nerve in the carpal tunnel)
Why do we test the ulnar nerve? - Answers Entrapments: elbow - cubital tunnel, wrist - Guyon's canal
syndrome
