There are numerous types of electrical muscle stimulation or electrotherapy. According to the Spine Health website, electricity has been used to treat pain for more than 100 years, and recent scientific evidence has shown that electrical stimulation can decrease both acute and chronic pain. Although its precise mechanism of action is still unknown, electrical stimulation is believed to block the transmission of pain signals along nerves and stimulate the release of endorphins, which are natural painkillers.
Transcutaneous Electrical Nerve Stimulation
According to Electrotherapy.org, transcutaneous electrical nerve stimulation or TENS is a type of electrical stimulation that reduces symptomatic pain by exciting sensory nerves and stimulating the pain gate mechanism and the opioid system. TENS describes any type of nerve stimulation delivered through the skin, although it usually refers to relatively low-power, pocket-sized devices prescribed for patients by their primary care provider, according to the Fast Pain Help website. TENS is frequently used to treat neuromusculoskeletal or NMS pain, and is one of the most well-known types of electrical stimulation. When delivered at a high intensity, TENS can stimulate long-term changes in the central nervous system that alter pain transmission along the nerves. TENS units can be worn for many hours at a time, and can be used at home by patients following detailed instruction from a physician.
Interferential Current
The Spine Health website states that interferential current or IFC is a deeper form of TENS. IFC is used by chiropractors and physical therapists to decrease swelling and inflammation in injured tissues. According to the Fast Pain Help website, IFC has also been shown to improve asthma symptoms and reduce back pain and osteoarthritis-related pain. The Texas Medical website states that IFC is characterized by the crossing of two independent electrical frequencies that work in concert to stimulate large impulse fibers in the area being treated. The frequencies generated by IFC disrupt pain transmission at the level of the spinal cord. The penetration depth of IFC can be adjusted to stimulate parasympathetic nerve fibers to help boost blood flow or circulation. IFC differs from TENS in that it penetrates deeper into the tissues, is more comfortable for the patient and increases circulation to help speed the healing of injured tissues.
Galvanic Stimulation
Galvanic stimulation or galvanism is a treatment method that involves the application of pulsed electric current to body tissues to stimulate muscle contraction. According to the Spine Health website, galvanic stimulation is effective for treating acute injuries associated with significant tissue trauma, including bleeding or swelling. Galvanic stimulation differs from TENS and IFC in that it uses direct current instead of alternating current. Galvanic stimulation's direct current generates an electrical field over the involved area that may favorably alter blood flow. The Spine Health website states that the positive pad used in galvanic stimulation acts like ice, causing decreased circulation to the region under the pad, reducing swelling, whereas the negative pad acts like heat, bringing increased blood, nutrients and oxygen to the injured tissues, speeding healing.
