How to use a Tens Machine & how Tens is thought to work
The Tens Machine transmits gentle, electrical impulses through your skin via self-adhesive electrode pads positioned on or around the painful area.
These gentle impulses attack pain in two ways:
- by stimulating the release of endorphins, the bodyís own pain-relieving hormones
by stimulating the nerves to block pain signals before they reach the brain
Conventional TENS relieves pain by having a direct effect on the pathway the pain is taking into the central nervous system. It reduces the sensitivity of the cells which transmit the pain onwards up towards the brain. Stimulation by TENS of the large non-pain nerves can reduce the activity of the pain transmitting cells for two hours.
More intense TENS stimulates the small pain-transmitting nerves, causing activation of the inhibitory mechanisms from other areas of the nervous system. It also tends to block nerve impulses going along a nerve in a sort of ďbusy telephone lineĒ effect. All the pain and all the TENS cannot get along the nerve, reducing the amount of pain signals which can get through.
When TENS signals enter the nerves, they travel both ways, up to the spinal cord and down to where the nerves start in the bodily tissue that is painful. These impulses collide with upcoming pain impulses and knock them out, reducing the total pain which gets through.
How To Use TENS
It is useful for you to have a pain assessment before you start TENS. That way we can find out what kind of pain you have and exactly where it is. If you have numb areas on your skin for example, these will need to be avoided as TENS needs an intact nerve pathway to work.
Two channel (four electrode) machines are more flexible especially if the pain is large or widespread.
- Start with conventional TENS with a continuous pulse setting.
- Use middle pulse frequency(approx 80-100 per second) and pulse duration (100-200 microseconds).
- Turn it up slowly until you can feel it, then gradually up it is strong and a bit uncomfortable, then turn it down slightly so itís comfy.
- You may need to experiment with the settings as there is no sure way of telling which combination will suit you without trial and error.
- Put the electrodes on normal healthy skin. Check to make sure you donít have any cuts or other breaks in the skin which could be very uncomfortable and react badly.
- Take time to find the best electrode placement Ė this may be tricky.
Donít use over hypersensitive areas which are painful to very minor stimuli. This can make the pain worse.
Avoid areas of reduced skin sensation as itís not effective and you may turn it up too much as you canít feel the intensity accurately.
If you canít place the electrodes over the skin area which relates to the nerve thought to be causing pain, you can place them along the nerve tracks. Diagrams are available to guide good placement. Click Here
Areas NOT To Put Electrodes
- Donít put them over the front of the neck as this can cause low blood pressure or spasm in the larynx.
- Donít put them over the eyes (you werenít going to, were you?) as this can increase the pressure in the eyes.
- Avoid putting them back and front through the chest, as stimulation here will go right through the heart and could affect its activity.
- Donít use it internally unless you have a specific device designed for this, and guidance in use.
You will notice there are often red and black leads with TENS machines. It makes no difference which way round you use them.
Working Out the Electrical Aspects of TENS
The intensity of the stimulation is the most important aspect of treatment because it determines which types of nerve get affected. You need to work up the intensity until you get the result you are looking for:
- Non-painful pins and needles means the large, non-pain nerves are stimulated.
- Painful pins and needles means the small skin sensation nerves are stimulated.
- Muscle twitching means the small nerves coming from muscle are being affected.
Research has not clarified which combination of electrical settings needs to be used for any particular type of pain. Trial and error is needed to establish the best settings for you within your comfort.
How Long To Use TENS and What Dose
Conventional TENS tends to have its pain-relieving effect very quickly, and lose its effect very quickly when the stimulation is turned off. People vary widely in how much post-TENS pain-relieving effect they report after treatment and the reason for this is not clear.
Higher intensities of treatment could result in longer term effects. The nervous system can get used to TENS over the long term (habituation) and lead to poorer pain control. If you stop using TENS for a while this can help, as can changing the electrode positions or the electrical settings.
As for all electrical stimulations, TENS should not be applied over a known tumour without specialist advice.
It is unusual to have any severe reaction from TENS. Skin irritation under the electrodes can be quite troublesome so itís important to remove the electrodes every day and wash the skin areas carefully. Moving the electrodes slightly to new areas of skin may also be sensible if you are sensitive.
TENS can be left on for long periods but if you are asleep and unable to monitor skin sensations, it might be best to take it off or use a timer which automatically does so after a time.
The Usefulness of TENS
TENS may be useful in acute (recent) pains but has been found to be helpful in many types of chronic (long-term) pain, especially musculo-skeletal problems.
Understandably many mums-to-be are hesitant about using analgesics during labour because of reports they can leave both mother and baby feeling drowsy and unable to nurse or bond properly for several hours after the birth. With tens machines there are no such risks; they can be used safely throughout labour with no adverse side effects at all. In fact some research has suggested that the use of a tens machine in place of analgesics actually reduces the risk of neonatal complications, leads to a quicker recovery from the birth and lowers the risk of a new mother developing postnatal depression. What's more a tens machine can safely be used to provide supplementary pain relief in conjunction with gas and air or pethidine treatments and their use is fully supported by nurses, midwives and doctors.
A tens machine can even play a role after the birth as when worn postnatally it can help to ease the after pains experienced as the uterus contracts, soothe back ache and can even help relieve discomfort from episiotomies or tears.
If you are hoping for a more natural birth experience then tens is definitely a pain relief option worth considering. As tens machines can be used effectively with massage, relaxation techniques, active positioning and even in preparation for a water birth, they really do offer the utmost flexibility when it comes to your birthing experience.
While tens machines are becoming an increasingly popular method of pain relief for childbirth they are still not widely available in nhs hospitals. For this reason if you would like to make use of a tens machine during your labour it's often best to hire or purchase your own; this can be done at minimal cost and will definitely be money well spent.
Pain is the body's natural warning mechanism and is intended to prevent additional injury. Pain is important, as without it, vital parts of our body might be injured or damaged without our knowledge. Whilst ointments, drugs or even surgery can be used to treat chronic pain, these are all utilised with varying degrees of success, as each individual patient and condition is different. TENS offers a unique alternative method of pain relief with no potentially harmful side effects, TENS is a very effective method of effecting pain relief for mothers giving birth.
WHAT IS TENS
TENS is a battery powered electrical unit which uses electrodes placed onto the skin over a painful area to deliver electrical impulses to the nerve fibres which lie underneath the skin surface, providing pain relief by blocking pain signals to the brain via the spinal cord and peripheral nervous system, TENS stimulates production of endorphines, the body,s own painkillers.
HOW DOES TENS PROVIDE PAIN RELIEF
TENS utilises the nervous systems own pain relief mechanisms. This may be achieved in two ways : either by stimulating Coarse nerve fibres mediating touch (conventional TENS), or by activating nerve fibres in Muscle (burst, acupuncture - TENS)
COMMON CONDITIONS TREATABLE WITH TENS
Although dependent on your Specific pain problem, TENS devices have been used successfully to treat many conditions, including:
Post Operative Pain
Phantom Limb Pain
Lower Back Pain
Muscular Shoulder Aches