The use of subliminal level currents, or microcurrents, for application in human injury and disease was introduced to the public by orthopedic surgeon Robert Becker, who discovered “currents of injury” when experimenting with amputated salamanders and/or other creatures that demonstrated spontaneous abilities to re-grow injured or missing body parts. This led to speculation that even humans may have had, or even may still have, some vestigial remnant of a similar physiological capability.
The scientific thrust came from Becker et al, but the popularity and demand for microcurrent electrical neuromuscular stimulation (MENS) was almost entirely driven by track and field superstar Carl Lewis in the 1990s. In mass media reports, the public saw Lewis apply MENS to recover from injury and even for performance enhancement, and later watched as he set world records. As a result, at the time our Detroit-based community hospital outpatient physical therapy clinic was inundated with requests for and queries regarding MENS.
The underlying premise for MENS application still focuses on some early research showing that the application of millionths of amperes of current to tissue could re-power or re-energize distressed cells by ramping up the production of adenosine triphosphate. MENS became the popular choice for tissue healing and was used for all types of musculoskeletal problems involving tissue repair (Table 1).
Additionally, 2 early observations were later borne out by research: 1) MENS application to the head for frontal and parietal head pain symptoms (headache) might be a safe and effective treatment, and 2) after several MENS applications, especially in the facial area for the treatment of neuralgias and palsies, an unexpected “smoothing” out of skin was observed. MENS facials are quite popular at salons and spas due to the collagen/elastic stimulation effects of the treatments. There also now is better understanding that MENS application can accelerate bone healing, and MENS is the basis for several European bone stimulators.
Strength of Treatment
There is no doubt that this form of electrotherapy sets the standard for subtlety and often is referred to as subliminal for that reason. This is not the treatment for patients who have to “feel” the treatment. For those more interested in the treatment effect, that’s a different story. The wide-ranging application of MENS is testimonial that it can have some profound effects on living tissue, including bone, muscle, nerve, and the various forms of collagen.
Ease of Treatment
A MENS treatment is straightforward, and set up is intuitive, with each channel having 2 lead wires and each wire terminating into a pigtail plug that inserts into a sticky pad for skin application. Generally the pad is placed or located directly over the painful area or target tissue, unless a probe stimulator is used instead of the pads; in this case, the practitioner will follow a meridian (acupuncture-like) approach, or a myofascial (trigger point) approach. Older technology will use a dispersive pad or electrode, but newer units might not.
When a patient with chronic migraine, cluster, occipital, or cervical tension-induced headache is responsive to MENS, it usually leads to provision of a home unit. Most of our patients will pay for these units 100% using their own funds and not through insurance reimbursement. That is a strong indicator of efficacy and how important this treatment can be for a patient.
MENS technology is quite inexpensive to own from a patient standpoint, but clinical and professional units can cost in the few thousand dollar ($2,000-$3,000) range. As a result, many facilities will use home units for clinical applications, since the end product can be identical. Practitioners have been using this technology for 20 years, and it has had time and opportunity to establish itself as a staple treatment in the domain of musculoskeletal medicine.
As with many other treatment forms and techniques in medicine, solid and convincing research is not in abundance. Practitioners who use this modality often do so in the absence of evidence and must rely on empirical information.