Surface Electromyographic Biofeedback
Hi, Bestie! As promised, today we’re chatting about surface electromyographic (sEMG) biofeedback. If you missed our last chat where we talked about the basics of biofeedback, catch up here.
What is surface EMG Biofeedback?
Surface electromyographic biofeedback (sEMG BF) is a type of biofeedback that picks up changes in the electrical activity of the muscles and relays these changes in visual or auditory forms. This type of treatment is used in pelvic health physical therapy in order to help folks to understand how their pelvic floor muscles (PFMs) are working. I like to think of sEMG BF as a mirror for your PFMs. For example, imagine you are at the gym and you want to work on your form during bicep curls. You could watch yourself complete bicep curls in the mirror and make changes based on what you are seeing. Maybe you notice your wrists aren’t flat or you see that your elbows are coming away from your ribs as you curl the weight. The mirror can help you pick up on things you might not otherwise have noticed and gives you real-time feedback so that you can make any necessary changes.
The PFMs are muscles just like any other muscles in the body. However, they are deep within the pelvic cavity which can make it more difficult to really understand how they work. When we use sEMG BF, we are getting information about the activity of the PFMs, just like we get feedback from the mirror during bicep curls.
How is surface EMG BF set up?
This type of biofeedback is typically done in the clinic with your provider. It is important to note that biofeedback itself does nothing to the pelvic floor or any other muscles for that matter. Rather, it is a tool used to aide in the training of the PFMs. For this reason, it is essential to start biofeedback training with your provider in order to develop a true understanding of how it is used and what you should be looking for. In recent years, smartphone applications have been developed for use of biofeedback at home. While these applications have the potential to be great tools, this type of biofeedback should always be initiated with the guidance of a trained professional.
Further, remember that biofeedback is not measuring your PFM strength. It measures the muscles’ activity at any given time, but this muscle activity cannot be mistaken as strength. This can be pretty confusing, but biofeedback is specific to each person that uses it. When using this tool, we are comparing you to yourself. We look at baseline levels and compare your PFM activity over time against these baseline levels in order to track progress.
There are two types of electrodes that can be used to measure the muscle activity of the PFMs in sEMG BF. The first is an intra-vaginal electrode. This electrode is placed inside the vaginal canal and its cord is connected to the biofeedback equipment in order for the signal to be relayed to the screen in use. The other type of electrode is a perianal electrode. The term “perianal” refers to the area around the anus. If using this type of setup, two perianal electrodes are placed on each side of the anus and their wires are then connected to the biofeedback equipment. There is also a “grounding electrode” placed over a bony prominence that is used to capture unwanted feedback and filter that out.
Both sEMG electrode setups are valid and work well. However, it should be noted that using an intravaginal electrode is much more invasive than using perianal electrodes. In fact, in folks with pelvic pain, it might not even be possible to insert an intravaginal electrode comfortably, if at all. Studies have shown that sEMG BF using perianal electrodes is just as effective as sEMG BF using an intravaginal electrode (1). I typically recommend using perianal electrodes as I aim to be as noninvasive as possible in my treatments. Also, use of an intravaginal electrode is expensive and this cost often falls on the patient rather than the provider.
What can sEMG BF be used for?
This type of biofeedback is a good tool for a wide range of pelvic floor dysfunctions. It can be used in treatment plans for underactive PFMs, overactive PFMs, and poorly coordinated PFMs (2,3).
Underactive pelvic floor dysfunctions may include things like vaginal prolapse, urinary incontinence, or fecal incontinence. In cases of underactive PFM activity, sEMG BF is used to help “uptrain” the PFMs. This means it can help you understand how to create a more forceful contraction of the PFMs, as well as a longer, more sustained contraction. When working on strengthening the PFMs, you will want to work on both power and endurance, and sEMG BF can help with both.
Overactive pelvic floor dysfunctions may include things like pelvic pain, urinary urgency, urinary frequency, urge urinary incontinence, and more. In these cases, sEMG BF is used to help “downtrain” the PFMs. This means it helps you to understand how to relax and elongate the muscles of the pelvic floor. It can also be used to help coordinate breath with pelvic floor activity.
Poorly coordinated PFMs can result in a multitude of symptoms, but a common one is urinary incontinence. For example, if you have a strong pelvic floor, but every time you bend over to pick up a pen you notice urinary leakage, your PFMs just might not be contracting at the right time. They have the strength to prevent urinary incontinence, but they don’t seem to have quite the right timing. In these cases, sEMG BF can be used to make sure the PFMs are contracting and/or relaxing at the right times. You would observe the screen showing your real-time PFM activity while picking up a pen. Then you could work on correcting abnormalities in PFM engagement while continuing to perform the triggering activity.
We’ll talk in more depth about each of the above types of pelvic floor dysfunction next time we chat. I want to get into what to look for during your biofeedback treatment session so that you know how your muscle activity should look and how to recognize abnormal muscle activity.
Chat soon!
XOXO,
Your Pelvic Bestie
References:
1. Özlü A, Yıldız N, Öztekin Ö. Comparison of the efficacy of perineal and intravaginal biofeedback assisted pelvic floor muscle exercises in women with urodynamic stress urinary incontinence. Neurourol Urodyn. 2017 Nov;36(8):2132-2141. doi: 10.1002/nau.23257. Epub 2017 Mar 27. PMID: 28345778.
2. Newman DK. Clinical Manual for Pelvic Muscle Rehabilitation. The Prometheus Group; 2003.
3. Shelly B. Methodology for Evaluation and Treatment of Pelvic Floor Dysfunction: Manual for Pathway MR-20 and MR-10 Surface EMG Biofeedback Devices. The Prometheus Group; 1994.
*The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a qualified health provider regarding any questions you may have about a medical condition or health objectives.
