Applications in Physical Therapy
Urinary and Fecal
The Use of Electromyographic
Biofeedback for Training Pelvic
Jacques Corcos, MD
Associate Professor, McGill University
Chief Department of Urology,
Sir Mortimer B. Davis
Jewish General Hospital, Montreal, Quebec
Stephen Drew, Ph.D. Biofeedback Associates of Northern California
San Rafael, CA
Linda West, RN
University of Tennessee
G.I. Division, Memphis, IN
Incontinence is a major healthcare problem costing a conservative
estimate of $10.3 billion, annually, in the USA. Patients with this
problem often lead lives of quiet desperation and social isolation.
Incontinence is the second leading reason for nursing home placement
with approximately 50% of all residents being incontinent. While it is
estimated that the number of incontinent geriatric patients can be as
high as 80%(15), it is more difficult to estimate the incidence in
younger populations. Sandler(17) claims that only one out of twelve
incontinent patients actually report their symptoms to their doctors.
One Danish study(6) conducted with a group of 45-year-old women found
that 22% experienced stress incontinence. The average length of time that a
woman is incontinent before seeking medical evaluation is 9 years. It was
also noted that only three percent of these women sought medical
attention for their problem.
A persistent myth is that incontinence is a natural part of aging. In fact,
fecal incontinence is prevalent even in children where approximately
1.5% of 7 year olds are affected(18). The true reason for incontinence is
seldom found. Many combined factors, other than age, including hormonal
status, childbirth, previous surgery, muscular dysfunction, physical injury,
medication, etc. are often responsible for the incontinence.
The three main forms of urinary incontinence are stress, urge and
overflow. Fifty to seventy percent is stress incontinence, which occurs
when the intra abdominal pressure is raised above urethral resistance.
This can happen while coughing, sneezing, bending, lifting a heavy object
or participating in athletic activities. Another 20-40% is urge
incontinence, which is the inability to inhibit urine leakage long enough
to reach the toilet when one senses the urge to void. Only 5-10% is
overflow incontinence, which occurs when the bladder cannot empty
completely because of obstructions or loss of bladder muscle strength,
and, thus, becomes over distended. It leads to frequent, and sometimes
nearly constant, urine loss, and usually requires medical management.
Urge and overflow incontinence are sometimes improved by
pharmacologic manipulations. Anticholinergic drugs are usually potent
inhibitors of contractions, and blocker agents can help when overflow
incontinence is secondary to a bladder neck obstruction such as prostate
Very few controlled studies have shown patient improvement of stress
incontinence using medication, estrogens, stimulator agents, etc.
Behavioral modification as a treatment modality for urinary
incontinence has been the focus of clinical attention only recently in
North America(1), although European doctors have used these
techniques for many years with a very high success rate.
The pelvic floor muscles are made up of the Levator Ani group and
include the pubococcygeus, puborectalis and the ileococcygeus. The
external sphincter of the urethra, as well as the anal sphincter are in
continuity with these muscles and both receive pudendal innervation.
Biofeedback, in conjunction with muscle contraction exercises, can
help strengthen the muscles needed to maintain bladder continence.
In a good review of incontinence(20), Tries states that the power of
biofeedback lies in it's capacity to shape patients to develop a greater
sense of control and mastery of bladder and bowel function, thus
reducing their fear, anxiety, and. A recent article in JAMA has gained
significant publicity and increased public awareness of this type of
A recent report from the U.S. Department of Health and Human
Services, Agency for Health Care Policy and Research(23) on urinary
incontinence, recommends that behavioral procedures, such as
biofeedback, be attempted before consideration of surgical or other
invasive techniques. The financial benefits of biofeedback were
emphasized in 1984 by Rodin of the U.S. Public Health Service(16),
who stated that if biofeedback techniques were used to treat
incontinence in the elderly, as much as $13 billion dollars a year could
Assessment of Incontinent Patients
Prior to being admitted to the biofeedback program, patients must be
evaluated by a urologist, or other physician with expertise in this field.
Some forms of incontinence, even genuine stress incontinence, could
be secondary to a general disease (multiple sclerosis, diabetes, etc.) or to
a local specific disease (carcinoma in-situ, interstitial cystitis,
tuberculosis, etc.) for which biofeedback treatment may not be
appropriate. However, in those cases, although biofeedback may not
ameliorate the underlying condition, it may improve the incontinence.
A daily bladder or bowel diary should be kept for at least 2 weeks prior
to beginning a behavioral program. This should include the number of
incontinent accidents, activity associated with the accidents and times of
regular voiding and fluid intake. The evaluation will include a review of
the patient's medical history, a vaginal and/or rectal examination,
assessing bladder and urethral prolapse, rectal prolapse, muscle strength
and ability of the patient to control his or her pelvic muscles. Usually,
only urine analysis and culture are required, although, depending on
history and physical examination findings, urodynamic testing,
cystometrogram, abdominal leak point pressure, and/or bladder leak
point pressure, x-rays and cystoscopy could be useful.
Electromyography Page 4 of 10
Wire with Disposable
Figure 1. Training Exercises
During the pre-treatment visit, the healthcare professional will provide
educational information and explain the use of the equipment, including
the sensor and its placement. Some patients express concern about
adequate sterilization of vaginal and rectal sensors. Single user sensors
may help reduce these concerns. If "T" shaped sensors (figure 1) are
used, the patient need not undress, and, if able, they should be allowed
to insert the sensor themselves, taking care that the large end remains
outside of the vagina or rectum. If a rectal sensor is used in elderly or
young children, some clinicians recommend that only someone with the
appropriate training and licensure perform a digital exam to rule out
obstructions, although the sensors do not very far into the rectum.Then,
holding the sensor (which has a dab of surgical gel on the tip) in one
hand, insert it while using a finger from the other hand to distend the
anal opening. Gently push the sensor into the orifice, until all but the
transversal end is inserted.
If surface EMG electrodes(9-10) are to be used, however, partial
undressing will be required. These electrodes are particularly useful for
the pediatric population and have been shown to have a recording
ability comparable with needle electrodes(9-10). The two active
electrodes should be placed directly adjacent to the anus and the ground
lead placed anywhere nearby (figure 2).
Electromyography Page 5 of 10
Figure 2. Peri-anal placement of surface EMG electrodes
find it valuable to
voluntary contractions. A suggested protocol follows:
The patient, fully clothed, is seated in a recliner. The sensor is then
connected to the EMG instrumentation. Using one of these instruments,
baseline information is gathered for the resting EMG levels of the
pelvic floor muscles. The resting EMG levels should be acquired over a
1-3 minute interval (typically under 2 microVolts rms). The patient is
then asked to tighten the pelvic muscles. Some clinicians suggest
visualizing trying to stop a stream of urine while voiding, and to hold
the contraction for 10 seconds (typically 10-20 microVolts in controls).
A period of ten seconds of relaxation follows each voluntary
contraction. It is important that the pelvic muscles are isolated and that
the accessory muscles of the legs, abdomen and buttocks are not
contracted. The clinician can generally observe this, but a second
channel of EMG can be utilized to monitor undesirable activity from the
abdominal region. The clinician should have the patient voluntarily
contract/relax the pelvic muscles four to six times. These voluntary
contractions should be observed for maximal amplitude, the average
amplitude of the ten seconds, recruitment and fatigue. The resting levels
should be observed for any spasms, as well as the time interval to go
from relaxation to the maximal amplitude of the voluntary contraction
and the time interval to return to the resting level. These measures
called "latency" are typically 0.5 seconds for contraction and 1.0
seconds for relaxation(14). If you are using a computerized program,
you can set the display time on the single polygraph screen to a 2
minute screen, after which you can save the data or copy the screen to a
Biofeedback Technique for Pelvic Muscle
The biofeedback approach for treating urinary incontinence was
pioneered by Arnold Kegel in the 1940's. Muscle contraction exercises
performed without EMG assistance can lead to contractions of other
Electromyography Page 6 of 10
muscles, such as the abdominals, buttocks and thighs, thus leading to
fatigue and overpressure on the bladder. Several researchers have
reported that EMG monitoring of the pelvic floor musculature through
surface electrodes yielded muscle activity that correlated highly with
fine wire needle electrodes inserted directly into the pelvic muscles(4-
11). Surface EMG has also been demonstrated to be a highly effective
treatment procedure(3,7,12,19). Home training with biofeedback has
been demonstrated to provide significant enhancements of
improvement in symptom reduction and elimination of urinary
incontinence when compared with Kegel exercises alone, or in
conjunction with a resistive device(13).
Through trial and error learning, EMG biofeedback permits one to
isolate only the pelvic muscles. If using a dual channel instrument,
such as the MyoTrac 2(TM) EMG system or two MyoTrac(TM) units
(both from Thought Technology Ltd.), one sensor can be placed on the
abdominal muscles, halfway between the umbilicus and the pubis, to
help the patient avoid abdominal contractions during pelvic muscle
Base flick Rest-Hold Endurance
Figure 3. Sample EMG line graph trace
There are several methods for training the pelvic floor musculature:
• Muscle strengthening is done with maximal contractions which
are held for 5-10 seconds at a time, with 10 second rest periods in
between. These are repeated several times, until the contraction
begins to show fatigue or when the patient begins to compensate
with accessory musculature.
• Endurance training is done with submaximal contactions held
for increasingly longer periods of time. For example, a 50%
contraction held for 30 seconds can be held longer at each
• Speed of recruitment is practiced with several repetitive
contractions (flicks) in a short time frame, for example, 10
successive contractions performed within ten seconds.
• A progressive contraction can also be done, asking the patient to
contract and relax gradually. The total biofeedback time is
approximately 15 minutes, the time spent on each type of
training depending on the patient's problem and response.
A review of the record-keeping data combined with a biofeedback
session, is usually suggested every 7-10 days with the healthcare
professional. The patient is asked to practice at home every day with
two or three EMG feedback sessions, 5 to 10 additional non-
instrumented muscle contraction exercises are also given. These should
consist of 3 sets of contraction and relaxation exercises per session to
begin generalization. During subsequent weeks, these exercises should
be practiced with an increasing number of repetitions and effort.
Several choices of monitoring instruments are available, single or dual
portable EMG systems which provide audio and/or visual feedback are
ideal for home training. A more sophisticated computerized data
acquisition system is recommended for clinical assessment.
Pelvic Floor Training with MyoTrac(TM)
• Set the MyoTrac(TM) scale at Xl and turn the threshold dial to
• Ask the patient to tense the pelvic floor musculature maximally
and keep the contraction.
• Turn the threshold dial counterclockwise until the first red LED
to the right of the yellow "threshold" LED is the one that is lit.
Note the setting on the threshold dial.
• Ask the patient to perform a series of 10 second contractions
which produce activity exceeding the yellow LED. If preferred,
turn the tone on fully, so audible feedback will accompany any
signal strength exceeding the threshold. Allow approximately 10
second rest periods between each attempt. If the first red LED is
significantly exceeded, re-set the threshold control to a higher
level in order to enhance strengthening.
• Instruct the patient to be aware of muscle activity in the
abdominal, buttocks and thigh regions, and to experiment with
relaxing those areas while increasing the EMG readings. If you
suspect that these muscles are being activated significantly, you
may wish to place an additional sensor connected to another
MyoTrac(TM) unit (or use a dual channel system) to demonstrate
the necessity to maintain low muscle activity in surrounding
musculature while performing the exercises. This is useful,
especially during initial sessions.
• Once you are confident that the patient understands the electrode
attachment and instrument setting procedure, you can proceed
with home training instructions.
If working with a child or infirmed elderly patient, the assistance of a
parent or attendant may be helpful. Clear instructions as to the
frequency of practice and maintenance of the equipment should be
A continuation of the daily records should be kept, these should include
episodes of incontinence, degree of activity during episode as well as
occasions of toileting without accident. It is imperative that the patient
continue the muscle contraction exercises, even with the resolution of
Incontinence is an extremely prevalent disorder. Biofeedback has had a
great impact upon incontinence, due to its ease of use, low cost and very
high success rate. EMG biofeedback can be used successfully, at home,
by most patients. Although treatment time varies, in most
people, continence can generally be restored in 4-8 weeks for both
fecal and urinary incontinence, using the techniques described in this
protocol, which combine clinical assessment and training with EMG
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