TENS (Transcutaneous Electrical Nerve Stimulation)
A significant number of my chiropractic and sports therapy patients already have a TENS unit at home or end up purchasing one from me as it can be a valuable adjunct to the services I provide at the clinic. I purposefully did not go into detail about what specific conditions you should use the TENS for; it is very important you seek out your health care provider to give you specific instructions pertinent to your individual health needs. Further, the embedded article goes into detail about the machine parameters and mechanism of action. It is quite lengthy but if you have a TENS unit, the material will be very beneficial to you.
TENS is a method of electrical stimulation, which primarily aims to provide a degree of pain relief (symptomatic) by specifically exciting sensory nerves. It can be used in several different ways, each being best suited to different pain relief mechanisms. Success is not guaranteed with TENS, and the percentage of patients who obtain pain relief will vary, but would typically be in the region of 70%+ for acute pains (strains, sprains, contusions, etc) and 50%+ for more chronic pains (fibromyalgia, chronic fatigue, osteoarthritis, etc). The technique is non-invasive and has few side effects, when compared with drug therapy. The most common complaint is an allergic type skin reaction (about 2% of patients) and this is almost always due to the material of the electrodes, the conductive gel, or the tape employed to hold the electrodes in place.
TENS Treatment setup – typical applications
1. Traditional TENS (Hi TENS)
Usually use stimulation at a relatively high frequency (90 – 130 Hz) and employ a relatively narrow pulse width (start at about 100 µs). The stimulation is delivered at normal intensity – definitely there but not uncomfortable.
It is suggested that in order to reach deeper lesions, the pulse duration should be increased.
2. Acupuncture (Lo) TENS
Use a lower frequency stimulation (2-5 Hz) with wider (longer) pulses (200-250 µs). The intensity employed will usually need to be greater than with the traditional TENS – still not at the patients’ threshold, but quite a definite, strong sensation.
3. Brief Intense TENS
This a mechanism which can be employed to achieve a rapid pain relief, but note, some patients may find the strength of the stimulation too intense and will not tolerate it for sufficient duration to make the treatment worthwhile.
The pulse frequency applied is high (in to 90-130 Hz band) and the pulse width is also high (200 µs plus). The current is delivered at, or close to the tolerance level for the patient – such that they would not want the machine turned up any higher. In this way, the energy delivery to the patients is relatively high when compared with the other approaches. It is suggested 15 minutes at this stimulation level is the most it would normally be used.
4. Burst Mode TENS
As described above, the machine is set to deliver traditional TENS, but the Burst mode is switched in, therefore interrupting the stimulation outflow at rate of 2 – 3 bursts/second. The stimulation intensity will need to be relatively high, though not as high as the brief intense TENS.
Target the stimulus at the appropriate spinal cord level (appropriate to the pain). Usually start with the electrodes either side of the involved area. You can use other stimulation points so long as the TENS activates the sensory nerves that enter the cord at the same neurological level. One can therefore employ nerve roots, the course of the appropriate peripheral nerve, motor points, trigger/acupuncture points, the same dermatome, myotome, or scelerotome. If the pain source is vague, diffuse, or particularly extensive, one can employ both channels simultaneously, and some health care professionals use a cross over technique in an attempt to increase the intensity of the stimulation.
If you have a TENS unit and would like a greater understanding of it’s applications, please consider booking a consultation with one of our Chiropractors.
Have a great day,
Dr. Crysta Serné
Vancouver Chiropractor and owner of Vitality Clinic