How will lotion effect emg?

Answer 1

Lotions, oils and other topical stuff can cause problems with your EMG test in 2 different ways.  First, they can cause the sticker-like electrodes not to stick & this can be quite frustrating to the person doing your EMG examination.  Second, your lotion can cause something called impedance mismatch, which results in crazy looking activity that will interfere with you doctor being able to obtain useful information.  

Answer 2

Lotion is most problematic to the nerve conduction studies (NCS) portion of the electrodiagnostic evaluation, but it may also effect the needle-EMG (nEMG) portion of the examination. Surface electrodes are often used for both the NCS part and the nEMG part. With lotioned skin, the surface electrodes may not apply well to the skin surface (they may not stick!). We also sometimes note that unevenly applied lotion will result in electrical skin resistance that is different over different regions of skin. When this difference in resistance is seen with recording electrodes it is called impedance mismatch and can prevent accurate recording or electrical potentials.

When having an electrodiagnostic study it is advisable to not apply any lotions, oils, creams, or ointments on the day of your appointment. You should also bathe and vigorously wash your skin prior to your appointment. You may also want to wear loose fitting comfortable clothing.