Place TENS electrodes in close proximity to the site of the pain. Do not allow the pads to touch each other, and place them at least 1 inch apart.
Make a note of where the pain is located; pinpointing the source of the pain is helpful in electrode placement. Always use the pads in pairs, either two or four pads depending on the specific TENS unit, according to Omron Healthcare. The distance of the pads from each other alters the strength of the electrical current. Place the pads vertically, horizontally or at an angle.
To get the most benefit out of the stimulation, adjust the electrodes according to the extent of the pain. In most cases it is advisable to place the pads on either side of the pain with the electrodes parallel to each other. Do not place the pad directly onto a joint; watch electrodes that are near joints to ensure that movement does not alter the pads' positioning.