What is a normal F wave?

Maximum normal F wave latency for median nerve was 25.7 ms for women and 28.5 ms for men with stimulation at the wrist. It was 23 ms for women and 25 ms for men with stimulation at the elbow. Maximum normal F wave latency for ulnar nerve was 26.45 ms for women and 28.9 ms for men with stimulation at the wrist.

What is F wave latency?

The F wave minimal latency is the parameter that is normally used to arrive at a clinical diagnosis. Each skeletal muscle is usually supplied by two or more nerve roots. If one root is affected and the other is spared, the F wave minimum latency might still be normal.

What does abnormal F wave mean?

If analyzed correctly, the F-wave is the most sensitive and reliable nerve conduction study for evaluating polyneuropathies, and it can be abnormal in focal proximal nerve dysfunction, can be used to evaluate radiculopathy, and can provide a meaningful physiological window into disorders of the central nervous system18 …

What is distal latency?

The distal motor latency is the time in milliseconds that it takes the impulse to travel from the stimulation point at the wrist to the recording electrode, say 3 milliseconds (ms).

What is peroneal nerve damage?

Common peroneal nerve dysfunction is due to damage to the peroneal nerve leading to loss of movement or sensation in the foot and leg. This condition is also called common fibular nerve dysfunction. Blood clot formation in the veins is called venous thrombosis.

What are the F-waves in nerve conduction studies?

F-waves are the second of two late voltage changes observed after stimulation is applied to the skin surface above the distal region of a nerve, in addition to the H-reflex (Hoffman’s Reflex) which is a muscle reaction in response to electrical stimulation of innervating sensory fibers.

What does latency mean on EMG?

Onset latency is the time it takes for the stimulus to initiate an evoked potential and reflects the conduction along the fastest fibers. Peak latency is the latency along the majority of axons and is measured at the peak amplitude.

What is latency in nerve conduction?

Latency is the time from stimulation to the beginning of the recorded signal deflection. Distance is between the closest stimulating and recording electrodes. Measurements are in terms of the latency to response onset, the amplitude of the response, and the conduction velocity.