Neurophysiology is the branch of physiology in a medical specialty that studies the central and peripheral nervous systems through the recording of bio-electrical activity, whether spontaneous or stimulated. It encompasses both research regarding the patho-physiology along with clinical methods used to diagnose diseases involving both central and peripheral nervous systems. Examinations in the clinical neurophysiology field are not limited to tests conducted in a Laboratory. Electromyography and nerve conduction studies: These diagnostic tests of the peripheral nervous system, especially useful in evaluating diseases of the muscles, nerves, and nerve roots. Records electrical activity of the muscles and the passage of them along nerves in the limbs.