TENS, transcutaneous electrical nerve stimulation, is commonly used to treat the muscle tension in TMJ and other types of chronic pain. TENS uses a very low-powered current that is safe for regular use.
Voltage, Amps, and Your TENS Unit
The current created by a TENS units may have a voltage range that goes up to 350 volts (V).
If you know that the typical household current runs at about 120 V, you may think this is a lot, but it’s no reason for concern, because voltage is only part of what determines the energy in an electric current.
An electric current is when electrons move. Voltage measures the potential for energy in a circuit. Imagine a current as electrons rolling downhill. Voltage is how steep and long the hill is, so how fast the electrons may be when they reach the bottom.
But voltage doesn’t tell us how many electrons are actually rolling down the hill. That’s measured by the amps (A) in a current. The amount of energy you receive from an electric current is determined by the amps times the volts times the time. TENS units use only a very small number of amps. In a typical unit, the settings don’t go higher than 700 mA or 0.7 A. Your house current reaches your breaker box with a current of up to 200 A, and each circuit in your house may have a circuit breaker that will usually trip at about 15-20A. This means that for the same amount of time, a TENS machine will expose you to less than 1/7 the amount of energy a house current does before a breaker trips.
And TENS exposes you for much less time. At its high-voltage setting, TENS uses pulses of about 100 μS (microseconds, or millionths of a second). A circuit breaker typically takes a full alternating current (AC) cycle to trip at the maximum amperage. Our AC runs at 60 cycles per second (Hz), which means it takes about 1/60th of a second, or a little less than 17,000 μS, for a circuit breaker to trip. This means that in total a house current will expose you to more than 1200 times the energy from a TENS pulse.
In other words, a TENS pulse delivers a small amount of energy, making it a safe level of current. If it’s set too high, you might experience some mild discomfort, but you won’t be injured before you have time to adjust TENS to a more comfortable level.
Who Shouldn’t Use TENS
Some people are at an elevated risk from electric currents, however, and shouldn’t use TENS. This includes people who:
Use a pacemaker
Experience epileptic seizures
Have a bleeding disorder
To learn about other effective ways to treat TMJ, please call (303) 691-0267 at the TMJ Therapy & Sleep Center of Colorado in Denver.