How do I know if an electrode is compatible with my machine?

All of the internal / insertable  electrodes we sell on Pelvic Floor Exercise are compatible with all of the machines we sell (stimulation and EMG)
Electrodes couple to a machines leads via 'male' and 'female' connections. The male connection is a pin and the female connection is recessed. The male fits into the female ( wonder where that came from?)
Most electrodes have pins which fit into the lead which in turn connects to the machine.

What is the difference between the electrodes?


Points of difference:

  •  comes in two sizes 20mm and 25 mm diameter so choice is dependent on hiatal or vaginal size
  • electrode plates are circumferential which can be advantageous for maximising potential contact esp if not sure of innervation or whether fully intact levators ( deep layer of pelvic floor muscles) 

When would I choose this electrode?

These electrodes are smaller in width so will suit those with a small to average size hiatus**
They can be useful if you are wanting to stimulate the urethral sphincter (at the front) as well as the pelvic floor muscles (levator ani) to the sides. As there are two bands of electrodes, you may in fact get some stimulation to both the superficial and deep layers of the pelvic floor muscles as well.
These electrodes sometimes suit women with mild prolapse as they are longer than the other types and can help reposition prolapse to allow electrical stimulation (as long as they fit your hiatal width - a factor in prolapse is often that the hiatal width is greater thus giving less support)

PFLEX Lifecare PR 18A : 

Points of difference:

  • Similar style to the popular Veriprobe which is no longer available.
  • A good all round electrode that has a flange on the base to assist insertion and to help ensure electrode plates are in correct orientation with the deep pelvic floor muscle layer.

When would I choose this electrode? 

Ideal for electrical stimulation of the pelvic floor, particularly for those with some activity or bulk in their muscles as it is narrower than the Periform.

PFLEX Lifecare PR 02A : 

Points of difference:

  • Rounded on the end and narrower at the flange, this electrode can be very helpful particularly for treating pelvic pain as following the initial insertion it is usually more comfortable and more easily retained within the vagina than one with a wider neck.
  • The round flange doesn't always allow you to know exactly which direction the electrode plates are facing but does allow for adjustment via turning if you are not feeling stimulation sensation where you want it.

When would I choose this electrode?

If you are treating pelvic pain, as it may stay in place more easily due to its shape,  good for EMG when down-training an over active pelvic floor, or for strengthening the pelvic floor if you have a smaller hiatus (the distance between each side of the pelvic floor muscles)**


Points of difference:

  • Has been designed to fit the shape of the vagina better, which is especially good for women with larger hiatus, ensuring better contact.
  • It is the sister product to the Pelvic Floor Educator, and can double as one as it comes with the same indicator stick . This allows you to see if you are doing a contraction - the stick will move downwards ( towards the tailbone) when activating the pelvic floor correctly and can be used whether attached to a stimulation machine or not.
  • The electrode plates  on the PERIFORM+ make it slightly wider than the Pelvic Floor Educator so can be used as an educator for women with a larger levator hiatus (LH) even if it is not being to be used for stimulation or EMG.

When would I choose this electrode?

If you are postnatal this is probably the best electrode for you to use for using with your electrical stimulation machine to strengthen your pelvic floor muscles. This is because it is the widest one and more likely to provide good contact with the vaginal walls and therefore conduct the current to the muscles surrounded the vagina. Once you have given birth vaginally the levator hiatus (the distance between each side of the pelvic floor muscles)** can be a bit wider.


Points of difference:

  • electrode plates contain base metals including a small amount of nickel. For users with a nickel allergy, this gold-plated electrode is ideal as it will not cause an allergic reation 
  • comes with an indicator stick similar to the Periform+ which acts as a biofeedback tool to assit with seeing/feeling the correct action and can be used separately as a pelvic floor educator.

When would I choose this electrode?

If you have an allergy to nickel you should choose this electrode


Points of difference:

  • comfortable easy to insert anal electrode that automatically sits in the correct position within the anal canal
  • can be used vaginally in very small women (obviously not if also being used anally)

When would I choose this electrode?

Most common uses are if you are a male wanting to do electrical stimulation for your pelvic floor, or for a female wanting to strengthen the EAS (External Anal Sphincter) and the back part of the pelvic floor. However they can be used for females who have a levator avulsion and therefore having difficulty getting good contact with a vaginal electrode, an anal one can allow successful electrical stimulation of the pelvic floor.


Points of difference:

  • small width with 2 circumferential electrode plates to ensure contact
  • narrowed neck to fit smaller anal verge

When would I choose this electrode?

If you have a very narrow anal verge, for a smaller person or can be used vaginally for a woman needing a much smaller width electrode


Points of difference:

  • longer insertable length
  • control depth of insertion and repeat insertion depth with collar
  • 2 circumferential electrode plates to ensure contact 

When would I choose this electrode?

If you have a longer anal verge - larger men for example. If you want to ensure the electrode is inserted exactly the same depth each time or you want to control how deep it is inserted ( the collar allows adjustment)

* PLEASE NOTE anal electrodes will only insert to their flange, they will not disappear inside

DOWNLOAD and read our electrode comparison chart HERE

** How do I tell the size of my hiatus?

The best way is to have an assessment with a pelvic floor physiotherapist, your gyneacologist or midwife. It invloves an internal examination to test the strength of the muscles, and the width of the hiatus.
You can self assess to get an idea by inserting two clean fingers into your vagina and trying to do a pelvic floor contraction - if your muscles are reasonably strong and intact then you should feel the two sides of your vaginal wall coming in towards your fingers and 'hugging' them. 

Your width is the distance that your fingers can be spread before feeling the bulk of the pelvic floor muscles against the vaginal wall.
If you can't feel this, your muscles may just be very weak and less bulky - and hence your hiatus will be wider. This can improve with exercises to strengthen and bulk up the pelvic floor muscles just like you can with other muscles.
Some women have damage to their pelvic floor muscles when giving birth, they can partially pull away from their attachment to the pubic bone at the front. This is called an avulsion and will result in a wider gap between the two sides.

See diagrams below indicating the hiatal width (on left) and an avulsion (on right) which gives a wider hiatus.

Diagrams used with kind permission of Lori Forner © Lori Forner


For pelvic floor electrical stimulation, which lubricant should I use?

Water-based lubricant is the best for use with vaginal and anal electrodes for assisting insertion. Only use enough to help insertion - you do not need it for contact as the electrode plates are in direct contact with mucosal tissue , unlike external electrodes which need to overcome the impedance of the skin in order to create contact. However if you have low natural lubcrication then you may need to use more.
If you are peri or post menopausal and your vagina and/or vulva are red/sore/itchy/uncomfortable please see your GP or gynaecologist first as you may need some oestrogen replacement cream to help improve the condition of the tissues prior to starting electrical stimulation treatment. You may also just need some extra lubricant.

Which external electrodes should be used?

This depends on what area of the body you are treating and what you intend to do.
The larger the electrode, the larger the surface area for stimulation delivery. To get the required depth, electrodes should be no closer than a pad size.
For example, a 50mm electrode needs to be 50 mm away from its nearest neighbour. 

Commonly used sizes :

  • 30mm round diameter are ideal for perianal use : stimulation or EMG of the EAS (External Anal Sphincter)
  • 40 x 40mm square and 50 x 50mm square are the most common sizes.
    These are ideal for TTNS - transcutaneuos  tibial nerve stimulation- and sacral nerve stimulation
    (50 x 50mm are supplied with the Neurotrac TENS)
  • 40 x 90mm  50 x90mm  and 50 x 100mm can all be used with Obstetric TENS for pain relief in labour and for persistent pelvic pain such as endometriosis - the electrodes can be used around the thoracic spine and the sacral area or, for pelvic pain, even over the abdomen. The 50 x 90mm are the standard size supplied with the Obstetric TENS. These can also be used with the TENS machine 
  • Size chosen will depend on patient size and intended use.

Do you sell electrodes that will fit machines that are not on your website?

All of our electrodes are female so as long as your leads are male they will fit. This applies to both internal and external adhesive electrodes.
However you need to check that the machine you have is able to do the job you want it to. 
For more on electrical stimulation  and TENS machines read Fiona's resource page

When using the vaginal electrode do you also use a surface electrode/s & if so where is the best placement for them?

You only need a surface (earthing) electrode if using EMG. In that case you place it on a bony prominence . The ASIS ( the bony bit at the front of the hip, just below the waist)  is usually used when performing EMG in the pelvic region. This is purely to reduce extraneous pick up of signals or artifacts.
For electrical stimulation you do not need an earthing electrode.

If I am just using surface electrodes where are they placed and how many do you use?

This depends on purpose of doing it and whether you are doing electrical stimulation or TENS. The most common uses of  external electrodes when addressing pelvic health issues are:

  1. When you are doing sacral or tibial TENS for urinary or faecal urgency or pain
  2. When doing any placement for pain -sacral, tibial, suprapubic, thoracic
  3. For EMG biofeedback especially for EAS (external anal sphincter) 
  4. When internal (vaginal/rectal) electrode use is contra-indicated or not appropriate.
    For eg:
  •  patient is too young
  •  never been sexually active
  •  not keen to try internal mode
  •  poor tissue compliance
  •  poor dexterity that may make using probe difficult.

Whilst much of the research indicates that direct stimulation gets better results, this will only be so if the user is compliant and comfortable using it.
Externally placed electrodes deliver current via indirect routes so to speak but along similar pathways.

It is generally accepted that you use 2 electrode pads via one channel for tibial stimulation and can use either one ( 2 electrode pads ) or two ( 4 electrode pads ) channels over the sacrum. 
Some people also use pads suprapubically which is not directly over any of the pathways. There is less research evidence for suprapubic application, however it has a calming sensory effect for some people and easier to apply at home.


The material presented here is intended as an information source only. The information is provided solely on the basis that readers will be responsible for making their own assessment of the matters presented herein and are advised to verify all relevant representations, statements and information. The information should not be considered complete and should not be used in place of the advice of a health care provider. Pelvic Floor Exercise does not accept liability to any person for the information or advice provided , or for loss or damages incurred as a result of reliance upon the material contained herein.

© Fiona Rogers, Pelvic Floor Exercise all rights reserved