Electromyography (EMG) is a technique for evaluating and recording the electrical activity produced by nerves and muscles. Interpreting EMG is a mandatory skill for neurologists and rehabilitation specialists. This textbook provides the reader with a detailed discussion of the concepts and principles underlying electrodiagnostic medicine. It is written for an audience without pre-existing knowledge in this discipline, including beginner technicians and physicians in training. It is an ideal review for seasoned practitioners and those preparing for board examinations. It begins with a review of the foundational sciences and works through the field in twenty chapters, including a large number of case studies demonstrating correct application and interpretation. Appendices of information frequently required in the EMG laboratory, such as Nerve Conduction Study techniques and their age-related normal values, anatomic regions assessed by each NCS and needle EMG studies, safety issues, and other important topics, are also included.