Microcurrent electrical neuromuscular stimulator
A microcurrent electrical neuromuscular stimulator or MENS (also microamperage electrical neuromuscular stimulator) is a device used to send weak electrical signals into the body. Such devices apply extremely small (less than 1 microampere) electrical currents to nerves using electrodes placed on the skin. One microampere (uA) is 1 millionth of an ampere and the uses of MENS are distinct from those of "TENS" which runs at one milliamp(mA) or one thousandth of an amp.
MENS uses include treatments for pain, diabetic neuropathy, age-related macular degeneration, wound healing, tendon repair, plantar fasciitis and ruptured ligament recovery. Most microcurrent treatments concentrate on pain and/or speeding healing and recovery. It is commonly used by professional and performance athletes with acute pain and/or muscle tenderness as it is drug-free and non-invasive, thus avoiding testing and recovery issues. It is also used as a cosmetic treatment.
The body's electrical capabilities were studied at least as early as 1830, when the Italian Carlo Matteucci is credited as being one of the first to measure the electrical current in injured tissue. Bioelectricity received less attention after the discovery of penicillin, when the focus of medical research and treatments turned toward the body's chemical processes. Attention began to return to these properties and the possibilities of using very low current for healing in the mid 1900s. In a study published in 1969, for example, a team of researchers led by L.E. Wolcott applied microcurrent to a wide variety of wounds, using negative polarity over the lesions in the initial phase, and then alternating positive and negative electrodes every three days. The stimulation ranged from 200-800uA and the treated group showed 200%-350% faster healing rates, with stronger tensile strength of scar tissue and antibacterial effects. In 1991, the German scientists Dr. Erwin Neher and Dr. Bert Sakmann shared the Nobel Prize in Physiology or Medicine for their development of the patch-clamp technique that allows the detection of minute electrical currents in cell membranes. This method allowed the detection of 20 to 40 types of ion channels that allow positive or negatively charged ions into and out of the cells and confirmed that electrical activity is not limited to nerve and muscle tissue.
A study by a neuroretinologist in the late 1980s suggested that microcurrent stimulation of acupuncture points for the eye had positive effects in slowing and even stopping progression of macular degeneration. This treatment is used to treat both the Wet and Dry forms of AMD. This study was based on Ngok Cheng's research on the increased amounts of ATP levels in living tissue after being stimulated with microcurrent. Several similar studies are currently under way and other studies have shown there are benefits (with specific microcurrent polarities and frequencies) on the healing of tendon and bone.
Mechanisms of action
While the mechanisms of efficacy are not well established, a few studies have shown that there may be a correlation between the traditional Chinese medical system of acupuncture and microcurrent. A study published in 1975 by Reichmanis, Marino, and Becker concluded in part that. “At most acupuncture points on most subjects, there were greater electrical conductance maxims than at control sites.”  The theory elaborated by Pierre Mathieu a Victoria Biomechanics specialist and TCM practitionner, was that the MENS is running one order of magnitude closer to the body's actual currents of only a few picoamps (pA) which are one millionth of a microamp itself one millionth of an Amp! The stimulation therefore is more in coherence with the body's own circuitry. The issue has been that generating stable square wave currents at microamp levels is already a challenge... but the real acting factor may actually be the magnetic fields generated by those currents which would equate with those conveyed by the metal needles employed in acupuncture. Some reverse experiments were therefore conducted from MENS clinical protocols to measure the actual Magnetic field Generation and then generating reduced magnetic fields to produce picoamp current stimulation in tissue. This has opened the door to further PEMF & electrotherapy modalities research.
Currently the Brooke Army Medical Center in San Antonio, TX, is running trials on MENS to control pain in service members referred to its pain clinic. Secondary outcomes will be measured for sleep, PTSD symptoms and depression.
Many companies manufacture microcurrent devices for both professional and personal use and microcurrent is in use as a "complementary" veterinary modality.
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- Park, RJ; Son, H; Kim, K; et al. (2011). "The Effect of Microcurrent Electrical Stimulation on the Foot Blood Circulation and Pain of Diabetic Neuropathy". Journal of Physical Therapy Science. 23 (3): 515–518. doi:10.1589/jpts.23.515.
- Cho, MS; Park, RJ; Park, SH; et al. (2007). "The effect of microcurrent-inducing shoes on fatigue and pain in middle-aged people with plantar fasciitis". Journal of Physical Therapy Science. 19 (2): 165–170. doi:10.1589/jpts.19.165.
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- Robert O. Becker, M.D.; Gary Selden. The Body Electric: Electromagnetism And The Foundation of Life. pp. 17–21.
- Wolcott LE, Wheeler PC, Hardwicke HM, Rowley BA (1969). "Accelerated healing of skin ulcer by electrotherapy: preliminary clinical results". Southern Medical Journal. 62 (7): 795–801. doi:10.1097/00007611-196907000-00008. PMID 5306004.
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- Reichmanis M, Marino AA, Becker RO (1975). "Electrical correlates of acupuncture points". IEEE Transactions on Biomedical Engineering. 22 (Nov, 22(6)): 533–5. doi:10.1109/tbme.1975.324477. PMID 1184029.
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- Deborah Powell. MicroCurrent for Horses (and other vital therapies you should know). pp. 15–84.