INNOVATIONS By Mark Atkinson, MBBS

Microcurrent therapy uses extremely small amounts of electrical current (millionths of an amp) to help relieve pain and heal soft tissues. It is an alternative, non-invasive approach for healing acute and chronic pain-related conditions (1,2).

How does it differ from TENS Transcutaneous electrical nerve stimula- tion (TENS) and other similar devices use a mild form of electrically-induced pain to block the body’s ability to perceive pain (3). When patients receive TENS at low fre- quencies (eight pulses per second or less), their production of endorphins may increase, producing temporary relief. The effect of TENS is believed to stimulate beta pain-suppressing nerve fibres to over- whelm chronic pain carrying C fibres. Massage, ice, and heat also relieve pain this way. Traditional TENS only works if the current is strong enough to feel, which can result in the administered current being as strong as 80 milliamperes. Increasing the current causes mild electrical burns in about one third of the patients, and the technique provides no significant residual effects in tissue healing (2).

Potential benefits of microcurrent therapy are that it:

● Is non-invasive and works at the cellular level to promote healing by mimicking the body’s own bio- electricity

● Increases the transport of nutrients and wastes in damaged tissues

● Augments endogenous current flow to allow traumatised tissue to regain its capacitance

● Perpetuates and initiates chemical and electrical reactions

● Replenishes ATP, which allows for increased amino acid transport and protein synthesis

● Increases protein mobilisation to the lymphatic system

● Increases the number of growth factor receptors, which leads to an increased production of collagen

A NEW WAY TO TACKLE PAIN

Microcurrent electrical therapy uses cur- rents in microamperage which are 1000 times less intense than those used in TENS, and below sensation threshold (2,4). The pulse width or length of time that the current is delivered is much longer than previous technologies. A typ- ical microcurrent pulse is about half a sec- ond which is 2,500 times longer than the pulse in a typical TENS unit (2).

It is usually administered through hand held probes positioned so that current flows between them through the painful area. Each application is conducted for about 10 seconds, and the majority of pain problems can be treated with less than 10 applications. Many patients are free of their pain in less than two min- utes, and there is generally a significant residual period of relief, often lasting from eight hours to three weeks or more (5).

Mechanisms of action Microcurrent therapy (MENS) can stimulate healing at the cellular level (1,6). Injury to the body disrupts its normal electrical activity; microcurrent therapy produces electrical signals similar to those that nat- urally occur when the body is repairing damaged tissues (6,7). Microcurrent machines are designed to mimic and amplify the body’s minute bioelectric sig- nals. They create a vehicle of electrical current to compensate for the diminished bioelectrical current available to injured tissue. This enhances the body’s ability to transport nutrients to and wastes from the cells in the affected area (1,2,4).

The physiological explanation Adenosine triphosphate (ATP) is an essen- tial factor in the healing process, and is the main source of energy of the cell. Large amounts of ATP are required to con- trol primary functions such as the move- ment of vital minerals, into and out of the cell (2). Injured tissues have higher elec- trical resistance, but are also deficient in ATP (2,4). When a muscle or tissue expe-

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riences trauma, the passage of bioelectric current is obstructed (1), resulting in electrical impedance that causes a reduc- tion in blood supply, oxygen, and nutri- ents to the tissue, leading to tissue spasms (2,4,8).

The decreased circulation causes an accu- mulation of metabolic waste products, resulting in local hypoxia, ischaemia, and noxious metabolites that lead to pain (2,4,8) reducing ATP production. The body’s electrical impulses lack the neces- sary current to overcome the impedance barrier inherent in traumatised tissue. This hinders the body’s ability to begin the healing process until the tissue has recovered from the trauma (2,7).

The correct microcurrent application to an injured site augments the endogenous current flow, allowing the traumatised area to regain its capacitance. The microcurrents reduce the resistance of the injured tissue, and bioelectricity is capa- ble of flowing through the tissue, thus aiding in re-establishing homeostasis.

Studies have shown that by using MENS at 500 µA (microamperes), ATP production increases, which enhances amino acid transport, and these two factors then con- tributed to an increase in protein synthe- sis (4,7,8). Currents exceeding 1,000 µA reduced amino isobutyric acid uptake by 20-73%, and protein synthesis was decreased by as much as 50% (4,10). MENS increased ATP generation by almost