In an earlier post he spoke of a treatment for chronic pain that was based on electrostimulation. Following this post, some readers have asked me to show how to use an electrostimulation device and, above all, where to place the electrodes. If you want to see basic concepts that should be known about electrostimulation I recommend going to the post of the link.
Almost all the electrostimulation devices that we can find in the market come preconfigured. They have programs with different objectives and we just have to mark what we want with a key. For this reason, talking in depth about the different parameters and their configuration would be complex and perhaps not very profitable. If there is interest I can go deeper into the future. In today’s post I will focus on some useful concepts and explain where to put the electrodes.
The first thing is to know what muscles we want to try and improve their abilities. In lumbar problems the main muscle that stabilizes the lumbar area and is affected is the paravertebral musculature. These are a group of muscles in the back of the lumbar vertebrae that perform the lumbar extension, that is, they carry the trunk backwards. The major and largest of these is the muscle called multifidus. When these muscles are contracted there is greater stability in the lumbar segments and that is why they are the most important . Training these muscles is critical to recovering from a back injury and to prevent further injury. Then we have the rest of the musculature that participates in the lumbar stability and that could also be trained with electrostimulation, as for example,
Concepts for using electrostimulation
Muscles conduct four times better when the current flow is made in the longitudinal direction of their fibers than when done in the transverse direction. The paravertebral musculature runs parallel to the axis of the column, therefore we will put the electrodes in this direction. Now we will see.
If the electrodes are very close, the stimulation is more superficial than when the electrodes are more separated. In the case of the lumbar extensor musculature it is okay to separate the electrodes from 2 to 5 cm.
The size of the electrodes is important. In the devices that are on the market are already indicated and no more thinking. Simply comment that the greater the surface of the electrode, the lower the current density and the lower the capacity to produce its effect and vice versa. For the lumbar area they are usually square and approximately 4 × 4 cm.
There is an electrode that is the active one that is usually smaller in size and one that is indifferent. The indifferent electrode is usually larger to decrease current density over neighboring tissues. In the case of the lumbar paravertebral musculature electrodes of the same size are usually used.
With the electrostimulator you can stimulate nerves and muscles, but each one will behave in a different way. If we stimulate a nerve, there comes a moment that does not respond, it needs a time to recover. This is called the refractory period. By stimulating the muscle this does not happen because it has no refractory period. That’s why we could stimulate the muscle repeatedly without letting it relax; Thus adding contractions developing a greater tension. We are interested in regulating our impulses so as not to become fatigued. The dwell time between pulses must be at least twice the time of action of the stimulator; Ie if we receive pulses for 10 seconds, the rest time must be at least 20 seconds.
You also have to increase the intensity progressively until reaching a certain value. If we raise it at once it can make the contraction very abrupt and annoying.
Where to put the electrodes for the electrostimulation of the lumbar extensor muscles?
In the apparatus we have two electrodes. One active and one reference. We have already seen that they would be of equal size. The lumbar musculature is symmetrical, that is to say, there is the same thing to each side, for that reason we are going to use four electrodes, two active and two reference. Two on each side of the lumbar spine axis.
The active electrode in principle is always said to be put in the motor point. And what is this about the motor point? The motor point is the area of the muscle where the greatest response occurs with the same stimulus. When a physiotherapist is treating us, he will take the trouble to find it before starting treatment. If we are using a device on our own this is not essential.
We will place the active electrode at the height of L4 and the electrode indifferent on L2. We can know where L4 is with a trick. If you look at the picture there are two ridges of bone that are the iliac crests. I indicate it with the line and the black arrows. At this level is L4. We want to put the electrodes on the muscle protruding area near the midline level between L4 and L5 vertebrae. We use the iliac crests reference and put the active electrode as shown in the picture below. Iliac crest be where frame with the red line and black would point where the active electrode. The indifferent (the green dot) would be placed 2 to 5 cm above coinciding with L2 approximately.
Electrostimulation of the lumbar extensor musculature
If these references cost us, we can do it another way. In the first of these last three photos I have placed two red arrows pointing to two bone protrusions that we can easily touch in the lower lumbar part. They would correspond with the orange dot of this last photo. They are two areas of bone that protrude on each side of the midline when we touch the lower part of the lumbar area. It is the so-called posterosuperior iliac spine. The electrodes would go above these bones but more glued to the midline.
Posture for the electrostimulation of the lumbar extensor muscles
The idea is to have a posture that allows an isometric contraction, ie without producing movement. There are many postures in this musculature. Look for a comfortable posture in which we can be without pain and where there is no movement. There are two that are adopted on a regular basis.
– A posture would be sitting upright in a chair. In this way the legs and pelvis are anchored and an isometric contraction can occur in a posture that is usually well tolerated.
– Another posture can be lying face down. Ideally put a pillow or similar under the pelvis and abdomen. This way the thighs are lower and the psoas relaxes. This makes us more comfortable and more likely to perform the session without pain.
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