TENS Unit and Myofascial Pain

TENS units, such as the Tech-Med TENS Unit, have been shown to be effective as a treatment that provides short term pain relief within a multidisciplinary approach to pain management. Chronic myofascial pain is a common medical problem that is often refractory to conventional treatments. The fascia, a complex web made mostly of collagen, surrounds muscle and provides connective tissue support for adjoining muscle systems. When injured through surgery, repetitive motion, an accident, or in conjunction with a postural problem or connective tissue disorder, injured fascia can trigger a local or regional pain syndrome, which includes muscle cramping, spasms, palpable "knots," tender trigger points, and referred musculoskeletal pain. When a treating physician attempts the use of analgesics, NSAIDs, muscle relaxants, or other pain management medications and the patient continues to face intractable pain, then the patient runs the risk of turning to a sedentary lifestyle, which ultimately compounds the problem.

In order to get patients to follow primary treatment guidelines, such as exercise or physical therapy, they require short-term relief from the pain and limitations in range of motion. Transcutaneous electrical nerve stimulation (TENS) units have shown excellent promise as a valid way to manage stubborn myofascial pain.

Choosing TENS

TENS units have been shown to be effective as a treatment that provides short term relief within a multidisciplinary approach to pain management. A TENS unit is a device that is equipped with electrodes that can be strategically placed on the skin at or near the tender trigger point. An electric pulse, which may be adjusted to various frequencies and intensities, enters the skin and travels through the tissue to nerve endings. While studies are ongoing, the current evidence suggests that the unit produces an analgesic action through stimulation of the peripheral and central nervous systems.

Not only have the benefits of TENS been shown in controlled studies to outperform placebos, but TENS units have performed as well or better than aspirin for patients suffering myofascial or musculoskeletal pain. In a separate meta-analysis study on postoperative pain, using TENS allowed the patients to receive fewer narcotics for pain relief, thereby lessening the side effects from medications. With a total of 1,350 patients studied, none of those that received TENS as a treatment suffered any adverse effects from it.

Using TENS

There currently isn't a professional consensus on the exact frequency and intensity to yield the best benefit. However, research is ongoing and suggests that, to reduce myofascial pain, high frequency, high intensity with settings of 100 Hz are the most effective. A study that looked at cervical range of motion and referred pressure pain threshold showed that using TENS with high intensity bursts, also at 100 Hz, for 10 minutes gave greater improvement than a placebo. Using lower settings, such as 35 Hz, does not show an impact on the pain, even when administered with other conservative therapies.

Electrode placement is a process that still requires study. Whether to place the electrode at a tender trigger point, a latent trigger point, or in the areas of referred pain may require judgment and results-oriented experimentation. It may be that the pain is as unique as the individual patient, or perhaps location is based on the underlying reason for the pain. While a person who has myofascial pain and limited range of motion due to de-conditioning following an accident or surgery has one set of needs, a patient with micro tears in the fascia from repetitive movements or a collagen disorder may need electrodes placed in a different location for the best results.

The Big Picture

As more research is performed on both TENS and myofascial pain, greater amounts of treatment strategies will be revealed. In the meantime, the research points to TENS being an effective weapon against chronic refractory pain. It can help patients reduce pain, thereby encouraging them to exercise. Combined with physical therapy, stretching and other non-invasive treatments, TENS units can help patients return to active lives with less pain.