Why is it that, after extensive
Physiotherapy, massage therapy, chiropractic, osteopathy and other forms of
treatment people still experience pain? Research studies are still working on
getting to the bottom of persistent pain, why some have it and others don’t.
The answer to the question is that
pain and our experience of pain is complex. For this article I want to focus on
body perception disturbance.
In order to have a better understanding
of what we are talking about, I need to talk a bit about the brain, anatomy and
physiology. My plan is not to go into great depths because that would turn this
blog into a series of novels. So a brief overview and if this sparks your
interest then I encourage you to research and learn more.
Let’s start with the sensory-motor
cortex in the brain. The sensory cortex is the part of the outer brain that
receives signals from the body regarding sounds, sights, smells, touch,
vibration and where our body is located in space (1). It is also involved in
planning movement.
The Motor Cortex is also located on
the outer part of the brain, right beside the sensory cortex and its involved
in planning, controlling and executing movement (2).
Another component of the brain
involved in body perception is the cortical homunculus, which is a distorted
representation of the body and its parts based on use and need for accurate
sensation and movement. For example on the picture you will notice the
representation of the hands is much later than the lower back. One reason for
this is that the hands need to be able to perform fine coordinated movements
and we use our hands very frequently where as we don’t need as much attention
to move our lower back.
Some individuals with persistent
pain have a distortion of their body perception which is defined as the
feelings of one’s own body (3). Studies have found that some individuals have
re-organization of their sensory-motor communication within the brain making it
difficult to make sense of the sensation and movements of a particular body
part.
An analogy I like to use is imagine
you had a clear google map of where you were going and then all of a sudden
that google map went all blurry. How difficult would it be for you to move
around and sense where you are in the world? Now imagine it’s the map of your
hand. Would your hand move coordinated? Would your hand experience sensations
in the same way it did before? Likely not, and that why some individuals
develop what is called complex regional pain syndrome or CRPS in their arm/hand
following an injury. CRPS is characterized by a disproportionate experience of
pain, unexplained swelling and discolouration of the skin and an inability to
even be touched lightly due to pain.
When researchers discovered this
reorganization in individuals with CRPS they began to wonder if the same could
happen to low back pain sufferers. Can the brain change in individuals with
chronic or persistent low back pain? The answer is yes. Studies have found that
some individuals with low back pain have reduced accuracy of touch (3), meaning
when the therapist touches their back they cannot correctly identify where they
were touched or if the therapist draws letters on their back they cannot
correctly identify the letters.
Individuals with back pain also cannot
sense their back very well (either it feels bigger, smaller or swollen) and
they have difficulty coordinating movement between the upper and lower part of
the spine (3). Individuals might describe that they have to think really hard
about making their back move the way they want it to or the right and left side
feels lopsided. These reports are indications that changes may have occurred in
the sensory-motor cortex and the homunculus map has “smudged” or gone “blurry.”
(3)
So how might a therapist know if
your body-perception has changed? Well we don’t have access to functional MRI’s
and other expensive equipment so researchers have worked on creating a short
questionnaire that can screen clients for body perceptions changes. The
questionnaire is called the Fremantle Back Awareness Questionnaire or the
FreBAQ. I have now implemented this questionnaire in my practice not just for
low back pain but other types of pain so that I might be better able to direct
treatment. Some other ways we can test for changes includes having the person
identify where we are touching with their eyes closed, what letters we are
drawing on the skin and/or 2-point discrimination. I also like to use other
questionnaires to help support the overall picture of why a person is having
pain.
Going back to the initial question
at the beginning of this blog. Why do some people not get better after
extensive treatment and exercise? While treatment and exercise are key
components in rehabilitation if someone has body perception distortion this
requires a different approach to help that individual essentially “refresh”
their google map. There are a variety of ways to do this using sensation and
movement strategies that are new and interesting. It is about increasing body
awareness and bringing mindfulness to movement and sensation.
So if you’re an individual who’s
completed extensive treatment perhaps body perception is a problem and finding
a therapist that has an understanding of this might be helpful in your healing
journey.
References:
- Wikipedia https://en.wikipedia.org/wiki/Sensory_cortex
- Wikipedia https://en.wikipedia.org/wiki/Motor_cortex
- Wand et al. Assessing self-perception in patients with chronic low back pain: Development of a back-specific body-perception questionnaire.