Author(s): Park TA, Harris GF
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Abstract This report describes a new technique for placing intramuscular fine wire electrodes into muscles for kinesiologic electromyographic (EMG) studies. Currently, a pair of fine wire electrodes (one active, one reference) within a hypodermic needle is inserted into the selected muscle. The needle is then withdrawn, leaving the two fine wires positioned within the muscle. Electrical stimulation of the muscle through these fine wire electrodes confirms their correct placement. However, if positioning is incorrect, additional pairs of wires are inserted within needles until correct placement is achieved. Our "guided" method combines this "blind" technique with diagnostic needle EMG techniques. Using a conventional EMG machine and selective activation of the desired muscle, the electromyographer inserts the hypodermic needle while monitoring the muscle's electrical signal through the advancing fine wire electrodes. This signal is used to "guide" the needle into the proper muscle. Once correct positioning of the wires is confirmed by the EMG signal, the needle is removed. With this techniques additional needle insertions are avoided, electrical stimulation is seldom needed, and rarely studied muscles are accessed as easily as commonly studied ones. We have used this technique with pediatric and adult patients as well as in kinesiologic EMG research and have found it to be well tolerated and reliable.
This article was published in Am J Phys Med Rehabil
and referenced in International Journal of Physical Medicine & Rehabilitation