The pain relief resulting from the low-voltage electrical current produced by transcutaneous electrical nerve stimulation (T E N S) units has made them popular among people suffering from muscle soreness in the back, hips, and arms.
Doctors and physical therapists usually recommend their use as part of a patient's musculoskeletal treatment program. However, some products are available over the counter or online without any recommendation from a healthcare professional.
If you have TENS unit pads, you have to know where to safely place them to reap the benefits of the electric pulses. Some TENS units have cables with sticky pads that are applied on the skin, while other pads are wireless. There are single-channel machines with two pads and dual-channel units that allow you to use two pairs or four pads.
TENS Therapy Isn’t For Everyone!
Despite being a non-invasive, drug-free type of therapy, you need to consult your physician before using TENS unit pads and electrical nerve stimulation under the following conditions:
- If you suspect you're pregnant.
- If you have heart disease, heart failure, or arrhythmias, as the introduction of electrical current may cause rhythm disturbances to the heart.
- If you have epilepsy because the electrical pulses may induce seizures.
- If you have a bleeding disorder, as the TENS may increase bleeding.
- If you have cancer and deep vein thrombosis due to the risk of metastasis (formation of new tumors) and dislodging of a thrombus (blood clot).
- If you have an implantable cardioverter-defibrillator or pacemaker.
- If you have poor sensation in an area where the muscle stimulator electrode pads will be applied.
- If the source of pain is on or around the area of a previous surgery where metal implants were inserted.
Moreover, TENS units shouldn't be used by children below age 16 without supervision. They also shouldn't be used by people with mental impairments or have trouble communicating and can't provide feedback.
Speak with your doctor if you're allergic to adhesives or nickel.
Electrode Placement Best Practices
To use the TENS pads safely and effectively, remember the following:
- Note the spot where you feel the pain. The TENS unit pads should be applied on each side of the painful area to allow the electrical current to pass through it.
- Clean and dry the area where you'll apply the TENS pads. Don't shave, but just clip excess hair using scissors.
- Depending on the instructions on your unit's manual, place a small amount of gel under each electrode. You need to use at least two pads at the same time; the unit won't work with just a single pad.
- Firmly and flatly place the pads for TENS units on the skin. The pad placement should be at least one inch apart. Never overlap them or let them touch. You can place the electrode pads on the skin horizontally, vertically, or at an angle.
- Hook the lead wires into the pin connectors of the electrodes before plugging the electrode wires into the unit.
- Slowly adjust to the correct setting, and set the time according to the doctor's prescription or recommended duration. Begin at low intensity and gradually increase the level as needed.
- Always remove electrodes by pulling in the direction of hair growth.
Avoid using your TENS unit while sleeping, bathing, showering, driving, and using machinery.
TENS Placement for Various Pain
You can use the electrodes to alleviate muscle pain anywhere from your head down to your feet. But you need to know how to position them correctly on your body, depending on the pain’s location.
For Headaches, Migraines
Place one pad on the temple where the pain is radiating, two pads on your nape, and one on your back shoulder. The TENS unit on your shoulder should be on the same side where you put the pad for your affected temple.
You can also place one electrode on the left temple and a second TENS pad on the back of your right hand, between your index finger and thumb.
For Neck Pain
Position two TENS units below your skull, on the left and right side of your spine. Then place two more pads below this pair or around the shoulder blade level. The gap between the upper and lower pair of electrode pads should be at least five centimeters.
For Shoulder Pain
Place an electrode on the fleshy muscle close to your nape, on the side of the hurting shoulder. Apply another pad close to the edge of your back shoulder but not on top of the bone. Follow the same placement on the other side if both shoulders feel stiff or sore.
You can also put two electrodes side by side on the upper arm, just below the head of the humerus or your upper arm bone.
For Back Pain
Arrange the TENS unit pads in a square formation around the area where you feel discomfort. Remember to apply the electrode pads on either side of your spine and not directly on top of it, whether it's thoracic (upper and middle) or lower back pain.
For Sciatica, Hip Pain
Sciatica is referred to pain felt along the sciatic nerve or from your lower back to the hips, buttocks, and thighs, usually one side only at a time. For pain relief, you can place a pair of TENS pads near the painful area on your back, on either side of your spine. Then you can apply two other electrode pads side by side just below your buttocks, behind your upper leg. You can also position the other pair of electrodes vertically instead of horizontally. If you have only two pads available, place one near your spine, on your lower back, and the other below your buttocks, in your hamstring area.
For Elbow Pain
Place a pair of electrodes above and below your elbow on the back of your arm. If you're using a dual-channel, put a third pad above the electrode on your upper arm and a fourth pad below the electrode on your forearm.
For Arm Pain
For upper or lower arm pain, position the TENS unit pads on either side of any area where you feel pain.
For Menstrual Cramps, Endometriosis
Place two electrode pads side by side or in a diagonal V-shaped formation on your pelvic region below your navel. You may also apply them on your back, just above the crease between your buttocks.
For Stomach, Intestinal Pain
You can line up a set of electrodes in front of your body horizontally and a pair on your lower back.
For Knee Pain
Place the electrode pads on either side of the knee cap, or place one electrode above it and the other below. If you're using a dual-channel unit, you can place a pair of TENS units above and another pair below the knee cap in a square pattern.
For Calf Pain
Apply the electrodes on either side of your leg or calf where there's muscle pain. Activate the TENS pads one leg at a time for some pain relief.
For Ankle Pain
Place two pads on your forefoot, one below the ankle joint and another above it.
For Foot Pain
Arrange four electrode pads in a square design on the affected forefoot. If you're suffering from plantar fasciitis pain, you can place the TENS units on the arches of your feet and the sides of your heels below your ankles.
Areas Where TENS Units Shouldn't Be Applied
To avoid injury or further muscle pain, don't place the TENS unit pad in the following areas: