PENS: A New Analgesic Modality in Physiotherapist’s Arsenal

Mrs. Ruby  Bose, 37, had an important family function  at her residence on Sunday. However, on Saturday during preparations of the function  she had a catch in her low back muscles. After the home remedies and  strong painkillers did not work the doctor sent her to  physiotherapy.

“She was never fond of needles”, her husband Dibyendu recollects, “but she didn’t really have a choice, she had to be fit for the gathering next day”. So when Dr. Das, PT informed her about a new procedure called PENS which can relieve her pain she agreed. And 15 minutes later became completely pain free.

“It was nothing short of a miracle. I mean I have taken physiotherapy before and they did help, but I never experienced complete pain relief in a single session” Ruby says.

So what is PENS? PENS stands for Percutaneous Electrical Nerve Stimulation. It is a combination of traditional physiotherapy modality, i.e. TENS with Dry Needling, a new age technique. To perform this the Dry Needling needles are inserted in the body first. Then the needles are connected with special resistor electrodes. These electrodes are in turn attached to a traditional battery operated low TENS machine.

PENS holds several advantages over TENS. First, the TENS is applied on the skin overlying the area of pain. TENS    impulses have to combat skin resistance and the resistance of the subcutaneous fat before they reach the source of pain. On the other hand PENS can be delivered specifically to the source of pain,  resulting in a much profound analgesia.


Secondly, both low TENS and Dry Needling releases endorphins in the CNS. Combining both together enhances each others effectiveness. By changing the frequency of impulses one can even tap into other neurotransmitter reserves, like GABA.

Third, because the skin resistance is bypassed it is much   easier to get muscle contractions via PENS as compared to TENS. The rhythmic pumping action helps to remove the metabolic waste products in the vicinity and also works to bring down the muscle spasm. This breaks the Pain-Spasm-Pain cycle and helps in early return to activity. This also means PENS is effective not only for analgesia but also in  resolving the pathology.

Fourth, PENS helps to stimulate both A-Delta and A-Beta fibers, which activate different parts of pain gate.

The effects of PENS are thus impossible to achieve by any other means. When used with strong clinical reasoning PENS often produce results which are in patient’s own words, “nothing short of a miracle”.

(Some names have been changed to protect identity)