The purpose of this review is to discuss electromyography (EMG) and so
me of the problems and issues that are encountered during the recordin
g and interpretation of EMG data. Recordings of electrical activity of
muscles can be contaminated by interference from the electrical suppl
y, mechanical artifacts, stimulus artifacts, and activity of other mus
cles The advantages and disadvantages of surface electromyography and
intramuscular EMG are compared and contrasted and precautions to be ta
ken when recording and interpreting these data are described Surface e
lectromyography is usually more susceptible to artifacts than is intra
muscular EMG. It is possible, however, to make useful recordings with
the surface electrodes from large superficial muscles if appropriate p
recautions are observed. Intramuscular electrodes, on the other hand,
may be preferred for recording the activity from small peripheral musc
les or muscles located deep within the body.