TENS – Further Information
What is TENS?
“Transcutaneous Electrical Nerve Stimulation” - quite a mouthful to say and read!
This technique of pain management is used and supported by virtually every hospital in the UK. Departments such as Pain Clinics, Maternity units, Physiotherapists, Post Operative Wards, Macmillan Nurses etc. TENS is used wherever pain is a major issue.
TENS is a battery operated electronic device. It generates a tiny but very special electrical impulse which, when applied to the skin (usually around the area of pain), stop the transmission of pain signals to your brain. No pain signals - no pain!
TENS is easy and pleasant to use. There are no side effects and you can use it alongside any other medication without fear of interference. It is completely portable and will not interfere with your normal activities. A 30 minute treatment can provide many hours of significant or total relief of even the most chronic pain.
How do you use TENS?
You simply place the self-adhesive
pads (electrodes) directly onto your
skin around or adjacent to the area of pain. (A comprehensive guide to
placement should be provided with any good unit but the final placement
will be determined by your own experience).
Choose any one of the available programmes (we recommend starting with a frequency of between 80 and 100Hz) and increase the intensity until you feel a moderately strong but pleasant tingling sensation.
You will begin to feel the benefit within a few minutes. The standard treatment time is around 40 minutes and this can provide several hours of significant or total relief from even chronic pain. Because it has no side effects you can use your TENS as often and for as long as you want.
How Does TENS work?
We are now exploring more of the science behind TENS. If you're interested read on, if not why not click here and look at one of our TENS machinesThe Gate Control Theory
This diagram shows the nerves coming into the spinal cord. The light blue box is the spinal cord. It is a very simplified diagram. In reality the spinal cord has many different layers (a bit like an onion) and information is passed through many junctions!
If you hit your finger, the blue pain nerve 2 goes from your finger up your arm to the spinal cord. It sends the pain information to the spinal cord nerves through 1 or 2 nerve junctions (shown by the dotted blue line) that are a bit like a gate across a path. If the gate is open you can walk through, if it’s closed you’re stuck there.
The red pain reducing nerves 1 & 3 come from the finger as well. They are stimulated by for example you rubbing your sore finger, using a TENS machine or acupuncture.
Nerve fibres carrying the pain message to the spinal cord are quite slow. Once the message reaches the spinal cord it is processed through several other nerves before passing up to the brain. Nerve fibres carrying the TENS message are much faster and reach the spinal cord first where they block the passage of the pain messages, effectively closing a gate.
TENS based on this process is known as conventional or high frequency TENS. The pulse rate is set at 60-80 pulses per second or more and this leads to a buzzing or tingling feeling. A lot of people find high frequency TENS produces the quickest pain relief, which lasts several hours
Low frequency TENS (Acupuncture like)
This uses low pulse rates of 2-4 per second and with a lower intensity
produce slight muscle twitching. You feel a tapping or pulsating sensation.
This method encourages the body to produce its own painkillers called
endorphins. It takes around 30 minutes to get pain relief but it can
last for hours or days.
It's called acupuncture like as the effect can be similar to acupuncture. Instead of using needles you use small currents. It's particularly effective for tense muscles especially if they have trigger points. These are small areas you can feel in the muscle that when pressed produce the response 'ouch'.
What are the Different Programmes and Frequencies?
What does Frequency mean?
The small current used in TENS isn't on all the time. It is a series of very short pulses. Each pulse only lasts a few millionths of a second. The frequency is simply the number of pulses per second and it is measured in Hertz (Hz). A frequency of 2Hz is 2 pulses per second. You can feel each pulse easily. A frequency of 40Hz is 40 pulses per second. It feels continuous like a buzzing. You can't feel the 40 pulses, they merge into 1.
TENS operates within a fairly wide range of frequencies from as low as 2 Hz to as high as 120 Hz.
At the higher levels it instigates “gateway control”. This effectively prevents the pain signals from moving along your nerve pathways. High frequencies act very quickly and give a pleasant tingling sensation which most of us actually enjoy!
The lower frequencies encourages the body to release it’s own natural painkillers - endorphins. Low frequencies produce a less pleasant pulsating sensation and can take a while to reach full effect.
By mixing your programmes (or using a programme that itself changes frequency) you get the benefit of both effects.
Everyone is different and we recommend that over a period of time you experiment to find the best programme for you as well as the best place(s) to put the electrodes.
