Page 45 of 56
EN109-1498740-40 IFU
Electrodes
–
placement
In general, both electrodes are placed on the muscle belly.
When placing an electrode over the target muscle, practitioners should always consider placing it
over the muscle's
motor points
. A motor point is defined as the surface entry point of a bundle of
motor nerve fibers into a fascicle of muscle fibers. From an electrophysiological point of view, a motor
point is defined as
a specific skin area where the targeted muscle is best stimulated with the smallest
amount of current amplitude.
There is a consensus in the literature that one of the major factors
limiting the clinical use of NMES is the pain, or discomfort associated with the delivery of electrical
current into the soft tissues.
Thus, by placing the stimulating electrodes over motor points as opposed to elsewhere over the
muscle, less current amplitude is used to generate maximum muscle force output, thus making NMES
more comfortable and effective.
To identify or locate motor points
–
prior to NMES - practitioners can refer to charts in text books
that illustrate the motor point standard location. However, the location of motor points quite
markedly differs from each other. Practitioners also can use the following motor point identification
technique:
Step 1: set the electrical parameter as follows:
•
waveform: rectangular pulsed biphasic
•
pulse duration: 150 µs
•
pulse frequency: 2 Hz
Step 2: use one small small-diameter stimulation pen (point) electrode with one larger reference
electrode, placed over the antagonist muscle (monopolar electrode configuration).
Step 3: place the pen electrode somewhere over the targeted muscle area. Slowly increase the
intensity while manually scanning the skin surface with the pen electrode, until a clear muscle
contraction is visualized.
Stop scanning and begin to slowly decrease the intensity until the muscle contraction becomes
barely visible.
Step 4: Mark this electrode position, which corresponds to a motor point, with a skin-marking pen.
Continue scanning the targeted muscle surface area until another similar muscle contraction is
identified, and mark it. Scan the entire targeted muscle area. Note that some muscles may have
more than one motor point. Place the surface electrodes over those identified motor points for
optimal NMES.
Flexible rubber electrodes
We recommend using the flexible rubber electrodes in combination with the supplied sponge pads.
When properly moistened, the sponge pads ensure low impedance between the skin and the
stimulator during treatment and they are easily cleaned afterwards. Follow the guidelines below
when using these electrodes.
•
Prior to initial use thoroughly rinse the sponge pads in warm tap water to remove the
impregnating agent.
•
Before application, saturate the sponge pads with tap water. Preferred is to use a saline solution
instead because of the improved electrical conduction.
•
The supplied sponge pads have three layers. With AC currents, apply one sponge layer between
the skin and the electrode for minimum resistance.
•
Fix the electrode/sponge pad assembly to the patient using the supplied fixation straps.
Depending on the electrode size, use two or three wraps to maximize the contact surface. See
the illustrations below.
•
It is important that electrodes remain in complete contact without edges lifting throughout the
treatment.
