From time to time, pelvic rehabilitation therapists ask this question: Does a pelvic rehabilitation therapist really need to "go there?" In other words, is subjective history taking, or perhaps surface electromyography (sEMG) enough of an evaluation and intervention to provide adequate care to patients with pelvic dysfunction? The short answer is no, and here's why: surface EMG is ONE tool for examination and intervention, and one that has limitations. The benefits of using sEMG are numerous: biofeedback has been utilized in much of the pelvic rehabilitation literature, with demonstration of efficacy as an intervention in conditions such as pelvic pain, incontinence, pelvic floor muscle training, and strengthening. Surface EMG, once equipment is acquired, is a relatively inexpensive method for providing feedback, or information about a typically unconscious activity, to the patient. Ideally, the patient internalizes the learned skills based on the biofeedback training and that skill is translated into functional applications such as letting go of a muscle group to avoid tension and pain, or activating a muscle to provide stabilization or protective contractions. So why is biofeedback alone not such a great approach?
Biofeedback does not always provide accurate information about a state of muscle contractility. Consider this fact which was highlighted effectively in Fitzgerald and Kotarinos' 2-part article about the "short pelvic floor": muscles need to produce an electrical event through firing of the motor units (action potential) in order to generate a reading on the biofeedback. When a muscle is in a contracture, or shortening without an active holding of the muscles, surface EMG readings can look "normal" even in the presence of tense, short, symptom-producing pelvic floor muscle states. Unless a therapist is using pressure biofeedback, inaccurate information is then provided to the therapist. Why else would a biofeedback-only approach not provide needed data upon which a pelvic rehabilitation provider bases his or her plan of care? Simply placing external sensors on the perineum or having a patient insert an internal sensor (without therapist observation or placement of the sensor) does not allow for appropriate inspection of the perineal skin, for the presence of prolapse, for the assessment of muscular tension or identification of tissues that are dense, tense, or pain-producing.
If sEMG is utilized in place of perineal observation, internal assessment, or interventions such as therapeutic activity, the therapist misses out on the opportunity to determine muscle tone, muscle tenderness in hard-to-reach places like the obturator internus muscle belly, or the nerve branches near Alcock's canal. It is impossible to know if one side of the pelvic floor is overactive, while the other side is non-functioning due to an old nerve injury or a new onset nerve dysfunction, if the sensors are testing both sides of the pelvic floor simultaneously. And finally, the lack of palpation and proper diagnosis can perpetuate a disconnect for the patient who is potentially relying upon external input rather than tuning in to her own body through the palpation, proprioception, and feedback of muscle states that the therapist can influence by using other evaluation and intervention skills. Consider also the challenge of keeping patients tethered to an sEMG device while trying to perform functional activities such as a golf swing, a lunge, or a jumping maneuver.