Sphincter electromyogram (EMG)
A sphincter electromyogram (EMG) is usually done in conjunction with a
cystometrogram.
As the bladder contracts to urinate, the sphincter (outlet) muscle should
relax. This test is performed to show how well the child's sphincter muscles are
working with the bladder muscle. It is electronically recorded.
Test procedure
- Two skin (round adhesive disc, like for an EKG) or needle electrodes will
be placed on the anal (buttocks) area. These electrodes measure the sphincter
activity (which is the same as the urethral sphincter activity). A ground
electrode is placed on the thigh area.
- These electrodes will be attached to a monitor (an electronic recording
machine) to record the sphincter activity.
- The monitor will be turned on and will begin to record all the pertinent
information. (If able, the child may be asked to cough and/or tighten and
relax her sphincter muscle to set the monitor properly).