MOTOR IMAGE AS A THERAPEUTIC INSTRUMENT AND THE OBJECT OF THE PROCEDURE IN THE REHABILITATION OF A PATIENT WHO SUFFERED A CVA
“Close your eyes and imagine walking…”
This is how I usually start the lesson about the motor image for the second year
physiotherapy students. Do it yourselves too, the ones who are reading this
article, close your eyes for a few seconds, and imagine yourselves walking, only
after doing it continue reading.
“Imagine walking…”
If you had the patience of closing your eyes and really imagine that you were
walking, then you will really understand this article. From what
perspective did you see yourself walking? Did you see yourself walking from your
back? Did you see yourself walking laterally? or you did not see around you and
just saw ahead in front of you? This question is fundamental in order to
understand if the image that you have created in your mind, is a visual image or a
motor one. In conclusion, did you see or feel yourself walking?
Thinking of walking, without really doing the action means that you have created
a mental representation of the action.
The mental representation can have different characteristics; for example,
aspects linked to the vision, and / or aspects joined to the perception of the
movement.
For example, if I would have asked you to imagine your favorite dish, the
representation would have also included aspects linked to the smell and the taste.
However, the mental image can be substantially rich in all of the informative and
perceptive elements, thus in this article we will emphasize the sensorial aspects
linked to the movement of the mental representation, which is known as Motor
Image (MI).
Definition of Motor Image.
“… the motor image can be defined as a dynamic state that during its lapse the person mentally imitates the action. This type of experience implies that the person feels that he himself is performing the action” (Decety 1996)
The motor image is the mental performance of a movement without a real
presence of any visible movement or muscular contraction.
Why talk about the motor image in rehabilitation.
The aim of this article is to demonstrate that the usage of the motor image in the
performance of the exercises for the recovery of the hemiplegic patient, is of
fundamental importance or at least an action of responsibility and reasonableness
which has to be considered in the treatment.
As we have many times highlighted, after having suffered a CVA the recovery in
itself is a learning process, thus if we had to discover that the image represents
a tool for the human being in order to make it easier to learn to motor again,
this process has to be considered cognitive in the daily work with the patients.
If we also had to take into account that in addition, the motor image expresses
the alterations after a cerebral injury, we would have to consider this process as
an object of our work in order to achieve the recovery.
Mental Image; Fantasy or biological phenomenon?
One of the most common obstacles when the motor image issue is mentioned as
an important part of the rehabilitation and the recovery of a patient who has
suffered a stroke, is his own mental nature, since it is very difficult to quantify,
and almost non tangible in respect to the physical parameters, like the strength,
the amplitude of the articular movement, and the speed of the movement. Also a
cohort is the term, “Image” since sometimes you run the risk to associate this
concrete cognitive and useful process, to the human behavior, the fantastic
scope.
Successively, we will go through some of the most relevant scientific studies,
which at the end trust the mental image with the load of the biological
phenomenon in all its effects.
Mental image and perception
Activation of the cerebral areas implied in the perception during visual
imagination tasks.
As proof that the image or mental representation is a concrete phenomenon of
our biology let us see what relation it has with the perception.
Many studies done by Stephen Michael Kosslyn, Psychologist, and Neuroscientist,
Professor of cognitive and behavioral sciences at Stanford and Harvard
Universities, have indicated how during the evocation of visual images during
perception processes, the same cerebral areas involved during perception
processes are activated, for example Brodman´s area 17, a posterior region of the
occipital lobe implied in the gathering of the information during the vision.
Therefore the data obtained from those studies, should make us reflect, that one
region of the brain implied in the elaboration of visual information during the real
moment of seeing, also comes involved during the moment of reconstruction of
visual images even though our eyes are closed.
This is a very important first contribution to entrust the image with a biological
role and that in addition demonstrates that its neurological canons overwhelm
those bound to a direct perception process.
Reduction of the mental visual field after an injury of the occipital lobe.
Another interesting contribution to the discussion over the relation between
perception and image was given by Martha Farah Researcher at the University of
Pennsylvania, in the cognitive neurosciences field, in her experiment done in one
of her patients whose occipital lobe had been partially removed, that is the part
of the brain responsible in great part of our ability to see and understand all we
see. Ms. Farah measured the mental visual angle of mentally evocated images
before and after the resection of the cerebral lobe and discovered that the
mental visual angle drastically reduced itself after the resection.
Therefore, after the elimination of a region of the brain, directly implied in the
visual elaborations, the possibility of mentally mentioning the visual images was
implied in order to show that image and perception shared neural substrates.
Neglect also present in the production of visual images.
In order to bring this important scientific information to our daily work, the
contribution from E. Bisiach and Luzzatti, who studied the alterations of the visual
image in patients with neglect after a cerebral injury in the right hemisphere is
needed. The authors of the study asked the patients in the study, natives from
Milan, to imagine the Piazza del Duomo, asking them to describe it mentally,
positioning themselves in the back part of the cathedral. The patients affected
with spatial hemi negligence (Neglect), described many details present to the
right from their place of vision and very little to the left; the relevant data was
that asking them later to mentally position themselves at the end of the square
and in the front of the Duomo, then they described all of the details not
mentioned before since from this new perspective they placed themselves on
their right.
The mental image maintains the metric and spatial image to the perception.
Kosslyn again, shows in consecutive studies, how the mental images maintain the
metric and spatial properties of the perception, studying the necessary time to
mentally analyze the objects and their real dimension, the bigger the object
dimension to analyze, the longer the time of said research.
The mental image is a biological phenomenon that induces biological
modifications.
These first studies about the visual image, have allowed us to surpass this first
obstacle which interpreted the mental representation as an only artifice linked to
the fantasy and to the mentalism, giving it a concrete importance and finally
placing it on a biological level.
“The motor image is part of a broader phenomenon (motor representation) the preparation and intention of movement fitted together” (Jeannerod 1994).
Further on, we will see that the mental image is not only a concrete and biological
phenomenon, but rather a cognitive process to such a degree that itself generates
changes and biological modifications.
In previous studies, there was an emphasis placed over the visual representations,
and still our abilities to create mental representations are not visual but neither
synesthetic, that is to say, linked to our body’s sensations.
There is also the case of the representations connected to the perception of the
body and the movement, hence the name motor image where we find a close
relation between the neutral substrates activated during the representative
process of the movement and the movement really performed.
Motor image and mirror neurons.
Let us do a little experiment that will help us explain how a mental representation
of a body sensation, has biological effects that indicate changes in our body and
also at a neuro vegetative level. Try watching this short video taken from You
Tube, of a child who is eating a lemon…
You have had the increase of salivation feeling, by just watching how a child was
eating a lemon.
Just the fact of seeing somebody similar to us performing an action has unchained
a particular identification process in our brain which has led us to live in ourselves
the experience of eating a lemon with the consequences that we all know.
This empathizing and identification mechanism takes place thanks to the
participation of a group of neurons in our brain called mirror neurons; mirror,
identified the first time, by an Italian researcher G.Rizzolatti, but the topic is so
fascinating and extensive that it is better to go deeper into it, in an article just
about it.
Motor image and metabolic changes.
In order to prove the fact that the mental image of the movement induces
metabolic changes in our organism even before the minimum gesture of starting
the movement. We are bringing studies done by Jean Decety, Psychology
Professor at the University of Chicago and Marc Jeannerod, French
Neurophysiologist, who revealed an increase in the heart and breathing rhythm
of people who were asked to imagine an effort like running or lifting weights of
different Kgs.
The hypotheses of the researchers in respect to such changes in the metabolic
answers of the organisms during the effort imagination and before the effort
becomes real, would be allowing and gradually preparing our body for the
performance.
The motor image keeps the metric and spatial properties of the action. Aside from
influencing the neuro vegetative answers from our body, the motor image seems
to have metric characteristics similar to the action in reality performed, just a bit
similar with what happened with the visual images which asked for more time to
recall them as their dimensions increased, also in the motor image we keep some
spatial and metric characteristics which will be found in the real gesture.
The same authors demonstrated it putting some people to a motor image task
like walking.
Activation of the cerebral areas involved in the movement also during the motor
image tasks.
Also in the case of the motor image, thanks to the functional magnetic resonance
studies, it was possible to observe that during a mental representation of the
movement, many of the areas which activate when the movement is actually
done also activate.
In older studies, the only area that was not involved, by the imagined task was the
motor one (Brodmann’s area 4) since it could seem logical due to the absence of
movement, although most recent studies have also identified a partial activation
of the motor area.
Primary Motor and Sensory Cortex Activation during Motor Performance and Motor Imagery: A Functional Magnetic Resonance Imaging Study
Carlo A. Porro et coll
“[… The results of this study indicate that functional activity levels in the posterior portion of the precentral gyrus, the presumed site of the primary motor cortex, are increased during mental representation of a simple sequence of finger movements, although the intensity of activation is lower than during real movements…]
The scientific evidence in relation to the activation of the areas linked to the
movement during the motor image tasks, has not left Professor Carlo Perfetti
indifferent, who since the 90s started to gear his investigations to show that the
motor image not only became one of the most valid tools in the neurocognitive
rehabilitation of the hemiplegic patient, but also an element in the profile of the
patient to be studied and influencing him in order to participate in the
recovery process together with the reorganization of all the cognitive processes
altered by the injury.
Up to now, we have been able to see that the motor image is an event of
our behavior which has biological bases, and in order to understand it, it is a real
and physical phenomenon not linked to fantasy.
We have seen that is closely connected to the perception sharing also on the
other side the nervous structures.
In other studies, we have also observed how the motor image has effects over the
¨physical body¨, modifying it, like in the example of the increase of the heart
beats and the breathing frequency. Now is the time of studying how the motor
image can also produce effects to the movement itself.
Motor Image and effects over the movement.
New investigations have shown very interesting and sufficient interrelated facts
for the rehabilitation post stroke world, like for example, those led by the
Spaniard Neurology Professor at the Harvard University, Álvaro Pascual Leone in
1995, in respect to the variation of the cortical presentation of the body during
motor image tasks.
The authors, through the use of magnetic transcranial stimulation, studied the
plastic changes of the motor cortex areas related to the index finger after the
motor image tasks.
If we have the chance to specifically speak, about the cortical presentations
relative to the body and the actions, resunterrelation mimos that
during decades were possible to map in our brain the projection areas of our
body, and our abilities of complying actions; at first the cerebral cartography
showed motives to think of a somatotopic representation of the human body,
allowing researchers like Penfield to draw up a true homunculus where each
point of the body had the only representation whether in motor regions or in
sensitive ones, but through the course of the research little by little, a more
complex cartography was started to be detected, where the body was not only
represented point by point, but rather in a multiple manner that answered to
different information and tasks, giving life to a true and own representation of a
mosaic.
The above mentioned study placed 3 study groups in comparison, 2 were asked to
learn a piano melody using all the fingers for a period of 5 days and 2 hours a day,
but only the first group was asked to really do it, the second was asked to go deep
into the desire of really doing it, but only doing the movement in their head not
physically.
Obviously, the third control group was not taught anything in order to make the
comparison.
The result was fascinating as it was reasonable, the extension of the cortical areas
of movement representation of the second finger was larger in the people of the
first group who had physically played the learned melody, but the researchers
noticed that also the second group who had not physically played the melody but
had done it with the motor image resource, had gotten the same enlargement in
the cortical areas of the second finger.
The group who was not asked to learn any ability and the group who was asked
later on to play the melody as they wished without learning anything, did not
show any significant enlargement.
These experiments supply the rehabilitator, specially the physiotherapist who
handles the recovery of the hemiplegic patient, a meaningful importance since
the first fundamental data is that certain modifications of the brain, after a
training session, happen if they are guided to learn an specific ability and not by
repetitive movements that we see in active and passive mobilizations and that
above all, such modifications can also happen interacting with the process found
in the ascending sense of the movement, that is to say its planning and prevision.
This last information enriches the pouch of possible tools of the rehabilitator who
wants to create the most significant therapeutical experience in terms of the
modification of the patient’s brain.
Motor Image and effects on the strength
We know the aspect referent to the muscular strength, which sometimes seems
to be one of the main problems of the hemiplegic patient, it is important and
represents one of the elements of the specific pathology of the post stroke
patient, but it is clearly the result of the alteration of the cerebral functions that
understands the movement. Nevertheless, with respect to the muscular strength,
many significant experiments were made, and the results will be brought in a
later on.
Guang Yue y Kelly J. Cole is an at random research done in 1992, researched
the increase in the muscular strength on 3 groups of healthy people. The first was
asked to do a reinforcement exercise for the pinky finger, making a movement
against the resistance in the opening, the second just only imagined that action
through the motor image task and the third was not asked for any task. In this
case, the results had been very concerted.
The first group who had been trained for 4 weeks in the real movement of
abduction of the 5th finger had a 30% increase in strength in respect to the
beginning, while the second group who had not physically done the movement,
but only mentally, the increase was similar, that is to say 22%. The third group
had an increase of 3.7%
The increase of the movement strength thanks to a training period using the
motor image represents an absolute enlightening scientific data, thinking about
our daily patients with cerebral injuries´ rehabilitation practice who partially have
lost the motor abilities in one side of the body (hemiplegia), but others who face
other types of therapeutic eventualities like the peripheral injuries of the
nerves, or the orthopedic injuries that for a long period of time, immobilize the
patient, mostly due to fractures or surgeries.
Another significant data from Yue and Cole´s study is that the increase in the
strength was not only found in the finger used in the training whether physically
or mental, but also in the contralateral hand, 14% in the physical group and 10%
in the motor image group, thus suggesting a participation of the contralateral
hemisphere in the training.
I came to have knowledge of such studies during the graduation thesis period, in
the meticulously described book by Paola Reggiani and Carlo Perfetti
“Immagine motoria come strumento dell’esercizio terapeutico edito dalla Biblioteca A. R. Lurija”
In a period where many end of the course students ask many questions, I wanted
to know about the effectiveness of a muscular treatment for the patients with
cerebral injuries which was consistent in passive and active mobilizations,
muscular reinforcement, development of neuromuscular reflexes and inadequate
things like tying up the healthy joints of the patients, these researches were like a
lighthouse that helped me start the fascinating world of the rehabilitation post
stroke. where instead of the same physical and muscular aspects, the cognitive
processes of the patient are also involved.
The revisions of the scientific studies up to now quoted demonstrate how not
only the mental image enters the internal biological phenomena, but also
determine the modifications in a biological level.
Now is the time to understand how and why the motor image is determining for
our behavior.
Motor image and behavior.
do not represent but just the tip of the iceberg
The human behavior is visible to the outside through our actions, the movement,
and the speech. These do not represent but just the tip of the iceberg, the visible
part, but should be considered as the emerging property of an elaborated
cognitive organization.
As in the perception case, our movement is closely connected with the typology
and the quality of the information that we are able to create with the surrounding
environment and our body. A typical example is walking; if we are able to walk in
a certain manner, is because we were able to have PERCEPTION and created the
necessary information in reference to the floor, its slope, carrying our load to the
support base, the spatial relations that go through our corporal segments in
movement, and many other bits of information, like visual, vestibular, and
propioceptive, among others.
Any alteration in our ability to perceive has an effect in our ability of moving.
However, the perception understood as a cognitive process cannot be studied in
an isolated manner, it has to be studied as an integrated part of all other cognitive
processes that take place in the behavior. At the beginning of the article, we have
studied how the perception and the mental representation shared the same
neuronal substrates.
All these scientific studies, before allowing us to use the motor image as an
integration tool of our daily actions, places us in a condition of asking what is the
meaning for the human being, of a so refined property that changes body and
mind into a final integrated inseparable unit.
Why should the human being be able to create the multimodal mental
representations, which can round up the intern of the various perceptive and
informative modalities, and why this imaginative property, shares so many neural
substrates with the real accomplished actions?
Another important question to make is: “Why such imaginative process is so
linked to the learning processes’”
Our answer can be found inside of the studies made about another great
interesting argument about rehabilitation: the cerebellum.
Motor image and cerebellum.
The Cerebellum which for decades had been interpreted as a structure internally
member of the motor coordination and center of the equilibrium, began instead
assuming the fundamental cognitive roles, be it making the provision of the
movement, be it the building of information with the external environment, or be
it the motor learning, and simply all the aspects where the ability to build
provisional images are fundamental.
As Lacourse had already identified during a motor image task, and other motor
an area, an activation of the cerebellum was also noticed.
They studied the simile cerebral activation regions by comparison between
people employed for the mental practice of the movement and people who
physically performed the movement. The results of this study was that additional
to the motor areas, there was also an activation of the cerebellum. The data in
this case acquires a very relevant value since after a cerebral injury the
cerebellum is one of the regions that suffer a deactivation at a distance.
Prevision, perception, and movement.
James M. Bower identifies the cerebellum with a fundamental role for the
acquisition of the information, thus it would act contributing to the perfectioning
of the movement.
Based on analyses of information gathered during a determined action, the
cerebellum ¨requires¨ from the motor cortex, a more exhaustive organization of
the explored surfaces in order to get from the environment and the body, more
exact information.
An incredible fascinating role of the cerebellum is that over the base of the
prevision of the results, it guides the fractioning of our body for a better gathering
of information with the environment, and always more elaborated which will
allow the ability to organize a more efficient movement.
Please take note of the circularity of the phenomenon: Guided by the fractioning
of the body in order TO get more elaborated information, TO guide a more
efficient fractioning, TO gather more detailed information. Hence the cerebellum
as we have seen it, activates itself during motor image tasks where at the same
time the perception and the movement participate through the gathering of a
prevision of the effects of the action.
In order to better understand how the motor image and then the making of a
prevision apparatus is fundamental for the rehabilitation of an action, we will
use the architecture of the behavioral act made by Pëtr Kuzmič Anochin.
Anochin was a Russian physiologist disciple of Ivan Pavlov, who in the last century
made a theoretical model about the functioning of the action.
At that time, he did not have all the powerful neuroimaging tools that we have
today, although, today that wonderful model for its ability to explain in a simple
manner the architecture of a complex behavioral act is used.
I will allow myself, to simplify it, with the promise of facing a complete discussion
in a separate article, leaving for the time being the title of the historic Anochin´s
text, which by the way, it is unfortunately almost impossible to find…
P.K.Anochin – Biologia e neurofisiologia del riflesso condizionato – Bulzoni Editore
– Roma- 1975 – Soviet Edition 1968
The environmental context and the biological needs where we station at a given
time, allow us “corresponding synthesis” that together with the attention, the
memory and the perception, represent the base over which a “decision making ”
is taken.
Once the decision of a determined action is taken, our central nervous system
contemporarily makes an ¨action program¨ necessary for its development and a
model for the control of the results of the same defined action.
“acceptor of the action”, this represents a prevision of the results, a presentation
that will guide us to understand if the results which we had proposed are
satisfactory or not, once the action is finished.
From the action program, we really start the action and the result will come as a
comparison between the generated model in precedence, if the prevision results
and coincides, then the behavioral act can be defined as finished, and a new act
can be started. In case, that the action results are not satisfactory, with respect to
the model generated in precedence, then more reorientation acts of the
corresponding synthesis will come, in order to get a more precise and
efficient new decision making and a new model of the action.
This theoretical model in respect to the functioning of our acting, aside of
reminding us the circular activity of our central nervous system, which molds and
reorganizes itself based on the constant analyses of the information that comes
from our body and our environment, makes us reflect over the biological
meaning of creating a mental representation of the results of an action even
before it is finished.
This is the way, through which our organism guarantees us the maximum
efficiency of an action and allows us to act and to learn without falling again in the
same costly activity of trial and error.
The object of this article is to study the scientific bases which will allow us to
intercept or not the necessity to involve the motor image in the rehabilitation
treatment of a patient who suffered a stroke. Up to this point, we have overcome
the first obstacle that for years has tied the motor image to the fantasy world
finally trusting it a biological role to all its effects, we have seen that such
phenomenon, aside from being in certain extent able to produce subsequent
biological changes; let us remember the neuro vegetative modifications of the
strength and the cortical representation during the mental imagination tasks.
Later on, we have identified the motor image as a fundamental cognitive process
for making an action and its efficient control, and that is closely related to another
fundamental cognitive process for our behavior: the perception.
We will see how the mental image is also interconnected with other cognitive
processes which represent the base of our movement: memory and learning.
Motor image and learning: in the healthy and in the post stroke patient
The recovery is a way of learning in pathological conditions, thus all our
connections with our abilities of learning, particularly the patient’s abilities of
learning and then recovery, should be studied with exactitude and considered in
the inside of our physiotherapeutic treatment.
“The definition of rehabilitation is the discipline that studies the learning in
pathological conditions and allows to entirely locate the characteristics of the
therapeutical conducts.” (Perfetti 1986)
Philip Jackson, Doyon and their collaborators in an interesting study about
learning thanks to the use of the motor image, have demonstrated that learning a
sequence of movements through the motor image, produces cerebro-functional
changes similar to those observed after the physical practice of the same
sequence.
In another study directed by Driskell e Copper, the effective meaning of the
betterment of the performance with the training through the motor image is
confirmed.
In a systematic review with reference to the mental practice effects over the
patients affected by a stroke, the German researcher Thomas Schack from the
University of Bielefield, concludes its study affirming the presence of certain
evidence at the “mental practice” has effects over patients affected by a stroke.
In addition it confirms the extreme necessity of structuring to the best level
possible, the procedures identified as ¨mental practice¨ because they also
perform the very complicated task of analysis. The manner to recall a motor
image, to verify its validity and the way how is associated to the exercise depends
on a number of variables difficult to classify, quantify and standardize.
This is one of the greatest obstacles in the systematic elaboration of the use of
the motor image in the rehabilitation.
The use of the motor image as a tool of the therapeutic exercise.
Within this article, we have seen overcoming the first obstacle in accepting the
motor image as a biological phenomenon able to determine biological
modifications, we have deepen the meaning of the mental representation in
reference to the human behavior, and now it is the time of handling the ¨how¨ to
take advantages of the motor image as a tool of the therapeutic exercise and
how to make it a point of interest for the recovery by the rehabilitator.
With that as a purpose, we take as an example, a classic cognitive rehabilitation
exercise according to Perfetti; the recognition of figures on the board; which
consists in placing the patient in front of a board where the figures with different
characteristics are, and he should recognize the figures with his eyes closed, and
using his finger tips moving throughout the board perimeter guided by the
therapist.
Let us watch a brief extract of a video where it shows the performance of the
exercise.
Here the therapist has explained the problem to the patient as the result of a
visual analysis of the ways to recognize and this will produce a perceptual
hypothesis, that is to say, an internal model, a mental representation of the
information to be received in order to recognize the way or using the term
already used by PK Anokhin: acceptor of the action.
The key element of this type of exercise is the presence of a problem that has to
be solved, it is not an exclusively mental problem, but rather a problem whose
solution will happen through the body and the use of all the needed cognitive
processes; hence the term neurocognitive.
The need to solve a problem by the patient activates the orientation of all the
needed cognitive processes, like the attention, in fact, the patient will have to
direct his attention to the most important information element, the figures and
his body in order to recognize the figure with his eyes closed. As we know, the
hemiplegic patient often has attention alterations, not only in quantitative terms
bit also in qualitative ones. For example he could direct his attention to the shape
aspects which are not relevant , or its partial body or any other not useful.
In the case of three silhouettes in a T shape, whose difference is detectable at the
height of the cylinder, the patient could not identify which side to pay more
attention to, or he could direct his attention only to the tip of his finger while
great part of the movement takes place through his shoulder and losing
significant and useful elements for the solution of the problem.
This initial analysis of the partial and disorganized afferents could lead to the
development of an action plan and an action acceptor inadequate for this
purpose.
The perception is an active process where the information that we build up with
our body and the environment are chosen over an election base. From this
analysis on, we understand that the result of the action not only depends on our
motor abilities, but also on the complex cognitive organization to its base which
starts with the attention choosing the relevant elements of the action, on the
perception and the integration of environmental and corporeal aspects and on
the feasibility of being able to make a prediction of the action.
Let us take into consideration that a cerebral injury determines an alteration
of the different levels of our cognitive abilities, like the processing of the behavior
then if we have to solve a cognitive type problem, we are allowed to detect and
act in each one of these cognitive components subjacent of the movement.
The physiotherapist’s role in this case, is to guide the patient, helping him to
reorganize and learn how to interact with his body and the environment.
The motor image represents a significant tool for that learning process, for
example when we are with a patient who could not choose the important sides of
the figure and the body parts where all his attention should be placed, we could
also propose the same contralateral of the injury joint exercise, pointing out
which were the meaningful elements of the recognition.
At this point, we can use the perceived “healthy” limb as a model to be
transferred to the affected hemiplegic limb, in order to reorganize the perception
expectation. For example, trying to do the movement with the healthy limb, the
patient can be made aware that the affected part of the body over which more
attention will be brought, is not only the finger’s fingertip, but also the shoulder,
and that the most significant part of the figure is the one related to the hat’s
height.
This manner of using the comparison tool, which has helped our patients create a
new afferent synthesis, can generate an action plan and more consistent results
solving tasks.
The patient will be asked to create an expectation of movement to be done with
his hemiplegic limb, based on the image created on the remembrance of the
movement of the healthy limbs.
In this case, we have used the motor image as a tool for the acquisition and
construction of more relevant information for the solution of the cognitive
problem, although we have to consider that the patient’s ability to develop a
mental representation which could have been altered after the cerebral injury,
remember what happened with the patients who suffered neglect, when they
could not create a complete image of the Piazza del Duomo?
A similar phenomenon takes place against the construction of a motor image, the
patient could have many problems developing a complete image of the
somesthetic (of the body) information and this could alter the action program
thus the results.
In this sense, the research made by the researcher Angela Sirigu in 1999, about
the alterations constructing an internal model of movement on patients with
apraxia and with parietal injuries in the left hemisphere is very interesting.
The patients were asked to recognize if the hand shown on a screen, was theirs or
of an operator, they were also asked to do movements with the hand and over
the screen with their own hand or one of an operator. The examined group had
less difficulties recognizing that the hand shown was unknown when the
movement was not the same, however they had more difficulties when the hand
shown was unknown (the operator’s) when the movement done and seen were
the same.
The author’s conclusions are guided to detect the reason of such alterations in
the ability of patients with right parietal injuries to make a kinesthetic (of the
movement) model which allows an efficient confront between what was expected
and what really happened on the screen.
In another study done by Sirigu, another very interesting aspect singled out in
order to better understand the motor image role in the movement
“Congruent unilateral impairments for real and imagined hand movements”
The researchers found that the quality alterations in the affected hand reflected
the motor image alterations of the same movement.
This is a very interesting matter for the rehabilitator, since it makes us consider
how the movement program of our patients reflects the current situation of their
movements inciting us to consider the idea that to incite about the movement,
we should be able to infer over the motor image which prepares and gives the
results.
It is difficult to think that one can improve the characteristics of a movement if
the program is carried out on the analysis of the pathological conditions. A
practical example in our daily life, let us imagine that we have a pain in the
shoulder while we are walking in a crowded street, we already know that if we
have a physical contact with the people it will cause a pain even before we bump
into them, our motor image already includes the presence of the pain, as we
know it.
In order to help the patient in the building of a complete hypothesis of perception
and confidence for the future performance of the movement, even to compare it
with the healthy limb, could mean helping the patient to reorganize his ability to
process the motor image more efficiently for the performance of the movement.
Some practical suggestions to investigate the quality of the motor image in the
patient.
It is not easy to investigate the quality of the motor image of our patient, but we
have some tools to evaluate the integrity and adaptation to the motor request.
The first way to evaluate the quality of the motor image produced by the patient
is obviously the result, if we do not observe changes or differences in the
execution could mean that his own produced prediction does not have all the
needed characteristics for the resolution of the task and its proper performance.
The timing as we have seen in previous studies stays between an action and an
image, therefore, if at the moment, when we asked the patient to build a motor
image, we realize that the time he takes to make it, is less than the time he would
use to perform it, then we can deduce that the patient’s image is incomplete or
that it favors visual characteristics over corporeal ones or even those
proportional, that is to say, made from verbal auto instructions, which in some
cases are also visible from the inside with light lip movements of the patient as if
he was making the image with words.
Some questions can help us look into the quality of our patient and be coincident
with the requested action, for example, if we are doing an exercise the first time,
or one where the patient does not have to make muscular contractions for the
movement, we can ask him:
“In the image that you have created in your head, who moved the arm, you or I?”
If the patient were to say, that in his head, he moves the arm then we have a first
datum which takes us to suppose that the image made is far away from the next
one. A more subtle question:
“In the image that you created where were my hands?”
If the patient takes a long time to answer, it means that in his image the
physiotherapist´s hands that holds his joint had not been taken into account and
most likely neither our support in his movement.
As we know, the hemiplegic patient´s mobility problems, very often are
characterized with the presence of spasticity, and also in this case, the
representation of the movement could include the existing characteristics when
the body had ¨rigidity¨, ¨nuisance¨ and ¨stubbornness¨, so also in this case we
should be able to help the patient to create a representation of the movement
that has different characteristics than the current one, only to allow him to be
able to get a better performance.
However, the comparison with the healthy limb, can be difficult for the patient
since the model offered for the healthy limb is way far from the lived reality with
the plegic joint and the quality of the transferred image can be incomplete and
not accessible by the patient.
In a recent 2012 study “The modulation of motor cortex excitability during
motor imagery depends on imagery quality” Lebon and his colleagues
demonstrated a close correlation between the motor image and the activation of
the motor cortex.
The rehabilitation data that we can gather from this study, is that the therapist´s
role, is also assuring himself that the patient can make a complete and intense
motor image, offering available and not distant models from the conscious
experience of the situation of his body, specially the plegic side.
An aid to locate the closest motor image for the patient and more significant due
to his conscious experience of the movement, is provided by the neurolinguistic
and by studies about the metaphor especially those led by George Lakoff,
Cognitive linguist at the University of Berkeley.
We have spoken more in depth in the articles:
- The speech as an instrument of the neurocognitive rehabilitation.
- The importance of the Metaphor in neurocognitive rehabilitation. Perfetti
- Mold the hemiplegic patient´s metaphor to modify the experience of the body.
However, in this context, let us remember that the patient understands what
happens in his body and he is able to explain it to another person using the
metaphor as a resource.
Let us take an extract of an often quoted conversation on the site:
- T: “What happened?
- P:“I feel a pull”
- T: “What do you mean a pull?”
- P: “Something that pulls”
- T: “And that something that pulls how is it?”
- P: “It is like an elastic band that when I try to make a movement pulls me”
The metaphor of the elastic band that the patient uses explaining the therapist
what he feels when doing a specific movement, is the way that the patient uses to
explain the phenomenon to himself and to his interlocutor.
It is a representation created at that given moment to explain the effects and to
tell his therapist his condition in order for the therapist to have an idea of the
event.
The patient creates a bridge between himself and the therapist and he does it
through a metaphor, which generates a representation for both, in order to
explain the aspects where otherwise the information would stay intimate and
inaccessible due to the subjective experience of the patient.
It is for this reason, that we have to try to guide the patient, to make a motor
image with better characteristics than the one already made, leaving it on his
conscious, and without contaminating the patient’s experience with our
experience and not asking him about an image far from reality like for example
one about his healthy joint.
A work hypothesis could be, to work over the same metaphor just given by the
patient, using a “Clean” language that allows the same patient to make an
approachable evolution of the current situation in order to allow the construction
of an accessible motor image with better characteristics than the preceded one.
You can find the complete explanation of this modality which assumes the
symbolic name of “MODELIZATION” in this article, but let us see how the
conversation with the patient and his “elastic band” continues:
- T: “If we are good, and work well together, how will you describe me that movement in a month’s time? “
- P: “Well, let me tell you that instead of having a green office elastic band, I will have a thinner, smaller yellow one”
- T: “So you will have a thinner, smaller yellow one…”
- T: “¿And could you imagine what feelings will you have when you try that thinner, smaller, yellow one?”
Here the physiotherapist invites the patient, to create a motor image based on
the new model that the patient has created, in order to extract from the new
metaphor, new characteristics that he will use to produce his new motor image,
thus his new real performance.
In this same symbolic article about “MODELIZATION”, aside from the complete
development, for example of the elastic band, you can also see a more through
explanation of all that happens in this video; you can see an example of the use
of the motor image in an aphasic patient, which I consider is useful to be also
repeated in this article.
Conclusions.
As we saw throughout this article, to speak about the motor image in
rehabilitation; a concrete and applicative discipline is not simple, however, in
these recent years, the scientific literature has been more attentive on this topic,
there are many obstacles to face in order to make its use, more systematic and
compatible.
I allude to the evocation and control methods of the quality of the motor image of
the patient. Nevertheless, bringing out all the scientific evidence as to the
effective meaning of the motor image in the behavior, It is not possible or at least
not reasonable for the rehabilitator, who takes care of the post stroke recovery,
not to consider the mental representation either as a tool or as an object for the
recovery of the hemiplegic patient.
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