Electrodes are central to all branches of electrotherapy. Their role is to facilitate the transmission of electric signals into the body. They do this by achieving a sound electrical contact between the patient’s skin and the device generating the electrical signal. This device could be a TENS machine, ultrasound unit, etc.
Choosing The Correct Electrodes
Size & Shape
Probably the most important factors to consider in choosing the correct electrode is size and shape. The correct size in any particular case depends on the area of the body that will be treated.
The main objective will be to make good electrical contact throughout the surface of the electrode. You may find that a smaller electrode works better on more contoured body areas.
The shape of the electrode can also be an important factor in ensuring good electrical contact. Depending on the specific area being treated, a round electrode may be a better choice than a square one, or vice versa.
The most commonly available electrode sizes and shapes are:
2’ x 2” square – these are a good choice for localized pain control, especially in highly contoured areas like the elbow or knee. The small size of the electrode means that it can achieve high conformity to the skin even in areas such as these.
This (or similar) electrode sizes are usually used in sets of 4. Typically, you buy an envelope of electrodes consisting of 10 sets of 4.
2” round – like the 2” x 2” square electrodes, these are a great option for micro targeting small painful areas. They can actually be oval shaped in addition to circular. They can provide conformity in even more highly contoured areas than the 2” x 2” square size.
Butterfly shaped electrodes are useful on large flat areas where conformity is not necessarily an issue. For example, they can be used effectively for lower back pain.
Another popular shape is a long rectangular one. They are suited for body areas such as the spine. They are also use for areas such as the, calf or thigh. They can be simply wrapped around these parts to provide optimum coverage simultaneously with excellent conformity.
Other Considerations
Besides the correct size and shape, you should try to choose electrodes that offer:
Excellent adhesion and conformity to the skin;
Reusability with no loss of conductivity;
A cloth backing that allows the electrode to more easily follow the contours of the skin.
A thick hydrogel layer that makes the electrodes easy to secure and that provide good current distribution;
A robust connection mechanism with the device supplying the current. The two most popular options are the “pigtail” connection and the “snap” connection.
Latex Free Construction
If you have sensitive skin or a history of latex allergies, you can choose to invest in latex free electrodes.
Using Your Electrodes
Electrodes are frequently used for pain relief in physical therapy. They provide a non invasive and efficient mechanism for managing pain and helping the patient comply with the prescribed rehabilitative program.
Electrodes are frequently used with Transcutaneous Electrical Nerve Stimulation (TENS) therapy to achieve this objective.
Electrodes can be used with TENS devices to mitigate pain from a wide variety of conditions. These include carpal tunnel syndrome,, arthritis, plantar fasciitis,frozen shoulder, sciatica and many others.
Electrodes can also be used with combination units (e.g. that combine therapies like ultrasound and TENS) for even greater efficacy.
Some tips for best practices when using your electrodes are:
Make sure that the area of skin to which you will attach the electrodes is clean and dry. If there is body hair in the area, it should be shaved off;
Avoid applying the electrodes to broken skin, or skin with rashes or any other visible damage;
Use your electrodes as a pair (one signal channel) or as a group of four (two signal channels). The precise configuration will depend on the type of TENS unit you are using. However, using just one electrode pad will not be effective;
Avoid positioning the electrodes so close to each other that they actually touch. Position them at least one inch apart;
As a general rule, the farther apart the electrodes, the less effective the treatment. Therefore, do not place them any farther apart than is necessary;
Avoid positioning electrodes directly over a joint such as the elbow or knee. The movement of the joint can reduce the adherence of the pad and compromise its conductivity.
