The additional value of using biofeedback in physiotherapy is related to patient selection and a better understanding of patient performance in activities advised by the physiotherapist during assessment and treatment.
Based on medical data, physiotherapists evaluate the patient’s symptoms of urinary incontinence to determine if, and to what extent, physiotherapy is indicated, or in other words, which patients will benefit from pelvic floor muscle training (Bernards 2014). The objectives of pelvic floor muscle training are to optimize muscular activation and force and the use of pelvic floor muscles as required for continuously changing daily work and sport activities.
Biofeedback registering EMG motor unit activity of the pelvic floor muscles provides unique information about pre-contraction, coordination, relaxation, and fatigability of the pelvic floor (Berghmans 2020). Pre-contraction is a prerequisite for adequate use of the pelvic floor during intra-abdominal pressure rise of any origin. Lack of or insufficient action of pre-contraction will lead to involuntary loss of urine, even when the strength of the pelvic floor muscles seems to be adequate during digital palpation of the pelvic floor (Berghmans 2020). The development of wireless biofeedback based on Bluetooth connection is an important step forward. Instead of the limitations of assessment on the physiotherapy treatment bed with traditional equipment and wiring, pelvic floor muscles can be assessed during regular daily activities.
There are different instrumental biofeedback technologies widely used in daily clinical practice, such as manometry, ultrasound, and EMG. With wireless EMG biofeedback many parameters can be assessed including timing, coordination, voluntary/conscious and involuntary/unconscious contraction and relaxation, explosive activation, endurance, fatigability, repeatability, and pre-contraction (also called fast-feed-forward-loop). This fast-feed-forward-loop contraction of the pelvic floor muscle might precede bladder pressure rise by 210-270 milliseconds (Ashton-Miller 2015). In female urinary incontinence this phenomenon is jeopardized, an important reason for the loss of spurs or drops noticed during stress urinary incontinence (Ashton-Miller 2015).
The valuable information now available through this innovative biofeedback will allow selection of a more effective pelvic floor muscle treatment strategy and procedure. To ensure an adequate sequence in pelvic floor muscle training, the concept of the ”5 Fs” (Find-Feel-Force-Follow-through-Functional training) of pelvic floor muscles has been developed and described (Berghmans 2017).
To find and feel EMG biofeedback is very supportive and should be used with those patients who are not aware, or are insufficiently aware, of where to find and how to feel the pelvic floor muscles. But here is the problem: biofeedback is an adjunct to pelvic floor muscle training and may be useful only for those patients who have lost their internal feedback mechanism for controlling their pelvic floor. All studies in this field have been performed in patient populations including participants both with and without awareness of how to control their pelvic floor, while only patients without awareness of how to find and feel the pelvic floor should have been selected. Had only patients without awareness of how to find and feel their pelvic floor been included, biofeedback would have its place for effective treatment for urinary incontinence.
However, high quality research still has to confirm this challenging statement and point of view. Until then, although frequently used in clinical practice, biofeedback will remain in the corner of inconclusive evidence.
REFERENCES
Bernards ATM, Berghmans B, Hendriks EJM. Dutch Guidelines for Physiotherapy in Patients with Stress Urinary Incontinence: An Update. Int Urogynecol J. 2014;25(2):171-9.
Berghmans B, Seleme MR, Bernards ATM. Physiotherapy Assessment for Female Urinary Incontinence. Int J Urogynecol. 2020;31(5):917-931.
Ashton-Miller JA, DeLancey JOL. Functional anatomy of the female pelvic floor. In: Evidence-based physical therapy for the pelvic floor: bridging science and clinical practice. Bø K, Berghmans B, Mørkved S, Van Kampen M (Eds). Edinburgh: Churchill Livingstone Elsevier; 2015. 19-34.
Berghmans B. Pelvic floor muscle training: What is important? A mini-review. Obstetrics & Gynaecology International Journal. 2017;6(4).