TENS Unit Placement: Where to Put the Pads for Common Types of Pain

01How

How TENS works

A TENS unit is a small, battery-operated device connected by wires to sticky pads (electrodes) placed on the skin. It delivers gentle electrical pulses that create a tingling sensation. According to the “gate control” theory, this stimulation reduces the transmission of pain signals to the brain. Lower-frequency settings may also encourage the release of endorphins. The NHS notes that TENS may help with some types of pain, such as back, joint and labour pain, but it does not work for everyone.

02Rules

General placement rules

• Place pads on or around the painful area, or along the nerve that supplies it.
• Keep pads at least 2.5 cm (1 inch) apart; do not let them touch.
• Use two or four pads, often in a square around the pain.
• Make sure the skin is clean, dry and free of creams.
• Switch the unit off before placing or moving pads.
• If one position does not help, try moving the pads slightly.

03Back

Lower back pain

• Place two pads on either side of the spine, at the level of the pain, not directly on the spine.
• For wider pain, use four pads in a square around the painful area.
• Keep pads on the muscles, a few centimetres from the midline.
• For lower back strains, combine TENS with movement; see lower back strain.

04Sciatica

Sciatica

• Place one pair of pads on the lower back on the painful side.
• Place the second pair on the buttock or along the back of the thigh, where pain spreads.
• Avoid placing pads behind the knee.
• Use TENS alongside exercises; see sciatica stretches.

05Neck

Neck and shoulder pain

• Neck: place pads on the back of the neck and upper shoulders, on either side of the spine; never on the front or sides of the neck.
• Shoulder: one pad on the front of the shoulder and one on the back, or pads above and below the painful area.
• Upper back: pads on either side of the shoulder blades.
• Keep pads away from the throat and head.

06Knee

Knee pain

• Place pads above and below the kneecap, or on either side of the knee.
• For four pads, form a square around the kneecap.
• Avoid placing pads directly on the kneecap bone.
• TENS can be used for arthritis pain or after injury, alongside exercise.

07Other

Other common placements

• Period pain: pads on the lower abdomen or lower back, around the area of cramping.
• Labour: two pads on either side of the spine at bra-strap level and two lower down, using a specific labour TENS unit.
• Hip: pads around the outside of the hip.
• Elbow: pads above and below the painful area on the forearm or upper arm.
• Foot and ankle: pads around the ankle or on the calf.

08Avoid

Where never to place pads

• Front or sides of the neck.
• Over the eyes or on the head.
• Across the chest, over the heart.
• On broken, irritated or numb skin.
• Over the abdomen during pregnancy (except as advised for labour).
• Over varicose veins or areas of active cancer.
• Over implanted devices.

09Settings

Settings and how long to use it

• Intensity: increase slowly until you feel a strong but comfortable tingling, not pain or muscle twitching (unless intended).
• Frequency: high-frequency settings (around 80–120 Hz) are commonly used for most pain; low-frequency (2–10 Hz) settings produce a tapping feeling.
• Duration: sessions of 30–60 minutes are common, several times a day.
• Take breaks to allow skin to rest and check for irritation.
• Do not use TENS while sleeping.

10Evidence

Does TENS work?

The meta-TENS study, which analysed 381 randomised controlled trials, found moderate-certainty evidence that pain intensity was lower during or immediately after TENS compared with placebo, for many types of acute and chronic pain, with few side effects. The Cochrane review of TENS for acute pain found tentative evidence that it reduces pain compared with placebo. TENS works best as part of a wider plan including exercise and other treatments, and its effects usually last only while it is used or shortly afterwards.

11Care

Caring for TENS pads and skin

• Store pads on their plastic backing to keep them sticky.
• Replace pads when they lose stickiness, as poor contact can cause discomfort.
• Move pads slightly each session to avoid skin irritation.
• Check the skin before and after use.
• Do not use pads on skin that is red, irritated or recently treated with creams.

12Summary

Key points to remember

• Place pads around the pain, at least 2.5 cm apart.
• Never place pads on the front of the neck, head, eyes, chest or broken skin.
• Use a strong but comfortable intensity for 30–60 minutes.
• Check with a doctor if you have a pacemaker, epilepsy, heart problems or are pregnant.