CHRONIC LOW BACK PAIN REDUCES OUR ABILITY TO JUDGE WEIGHTS
Chronic low back pain is pain that you have been experiencing for ages or pain that keeps coming back.
Have you had a situation where you have had a problem with your low back and then, when you feel a bit better, you start to do more and you just reach to pick up something that you think is going to be harmless and ‘bang’ – you irritate it again?
This happens frequently and there is a scientific reason for it!
In research carried out last year by Lussanet et al, it was discovered that those with chronic low back pain lose the ability to accurately judge anticipated weight, particularly when they twist at the same time as lifting.
If you have had back pain for a long time or you keep getting back pain then you may have changes in the brain that control the links between our muscles and our way of deciding what muscular activity is going to be appropriate to allow us to lift using muscles in the right way without damaging our back.
We need to co-ordinate the muscles in our core as well as those of our hands and arms in order to lift safely.
The part of the brain responsible for this co-ordination is the motor cortex.
It co-ordinates the planning, control, and execution of voluntary motor functions.
Similarly, in the human brain, planning for any given movement is done mainly in the forward portion of the frontal lobe. This part of the cortex receives information about your current position from several other parts of the body such as the hands. Then, like the ship’s captain, it issues its commands, to Area 6. Area 6 acts like the ship’s lieutenants. It decides which set of muscles to contract to achieve the required movement, then issues the corresponding orders to the “rowers”—the primary motor cortex, also known as Area 4. This area in turn activates specific muscles or groups of muscles via the motor neurons in the spinal cord.
Even for a movement as simple as bending over to pick up a glass of water, it is difficult to imagine trying to consciously specify the sequence, force, amplitude, and speed of the contractions of every muscle concerned. And yet, if we are healthy, we all make such movements all the time without even thinking of them and we move safely and without pain, over and over again.
The decision to pick up a glass of water is accompanied by increased electrical activity in the frontal region of the cortex. The neurons in the frontal cortex then send impulses down their axons to activate the motor cortex itself. Using the information supplied by the visual cortex, the motor cortex plans the ideal path for the hand to follow to reach the glass. The motor cortex then calls on other parts of the brain in order to co-ordinate the activation of the muscles in sequence.
The axons of the neurons of the primary motor cortex pass down the spinal cord where they make the final relay of information to the motor neurons of the spinal cord. These neurons are connected directly to the muscles and cause them to contract. Finally, by contracting and by thus pulling on the bones of the back and the arm and hand, the muscles execute the movement that enables the glass to be picked up.
In addition, to ensure that all of these movements are fast, precise, and co-ordinated, the nervous system must constantly receive sensory information from the outside world and use this information to adjust and correct the body’s trajectory.
Chronic pain interferes with these sensorimotor judgments.
What can we do about it?
You need to engage in a motor re-training programme that is targeted at retraining the cortex of the brain, which is very plastic, which means it can change and be reorganized given the correct input.
That is why we give you exercises – not just to make your muscles stronger but to change the function of your brain!!