There are several possible reasons why you are getting an irregular signal. 1) Electrode problems, such as dried-out or expired electrodes, inadequate skin preparation or electrode coming off. 2) Unused leads that are connected to the Noraxon System are not “shorted out.” This allows noise in the environment to affect the signal of the leads on the subject’s body. 3) Occasionally – The pre-amp lead is not functioning properly. 4) Rare – Analog Connector on Noraxon System is not functioning properly. For detailed troubleshooting techniques, please refer to the document Troubleshooting Irregular EMG Signals.