In the movie The Matrix the main character, Neo, is famously offered a choice between a red pill and a blue pill. If he takes the blue pill he forgets about learning about the Matrix and goes back to life as he has perceived it. If he takes the red pill, he joins the fight against the sentinels to save the human race. The movie depicts a dystopian future in which humans are turned in to slaves by machines. The machines create a simulated reality for the human’s mind while the bodies are used as energy to power the machines. Most humans in the Matrix are living two lives and are unaware of it because of the false reality created by the machines. Neo ends up taking the red pill and joins the fight against the machines. He lives two lives, one in reality and the other in the matrix.

Many of us are living two different lives as well, albeit not as depressing as The Matrix. As far as I know, our bodies are not being used as energy sources to power evil machines taking over the planet. Our two different lives are not reality and the matrix, rather; it is left and right. We have left and right sides of the body, both very different. Much has been discussed about left and right sides of the brain. Most humans have a “handedness” or a dominant side. We are constantly balancing our left and right.

Left and right worlds exist outside our human bubbles as well. Dogs have been shown to have a “paw preference” that correlates with their personality.  A recent study revealed that dogs have different emotional responses depending on the direction of another dogs tail wag. Seeing another dog wag to the left indicates stressful situation, and if it is going to the right they tend to be more calm and relaxed. Successful race horses are right-side dominant. Since tracks run counterclockwise, it favors horses that take longer stride with the right foreleg to help them turn to the left. Parrots tend to favor one foot when grasping objects. Humpback whales prefer to use the right side of their jaws to collect food from the bottom of the ocean floor. We drive our cars on the right, sit in the car on the left. Latin-based languages are read and written left to right. The drivetrain on my bike is always on the right, and thus rear bike wheels are different on the right and left sides. On the bathroom sink, cold is on the right, hot on the left. Jars tighten to the right and loosen to the left. Even our government has a left and right!

In my “matrix” as a physical therapist, I am very interested in the left and right side of the body. As mentioned in previous blogs, we are very different left and right. We have a heart on our upper left chest wall. We have 3 big lobes of a lung on the right, 2 smaller lobes on the left. The right side of our diaphragm is much larger than our left and we have a liver under the right diaphragm. The stomach rests more on the left side of the abdominal cavity. Even the left and right side of our heart has very different functions. Human motor functions are different left and right. Our left and right sides are positioned differently when we clap our hands and cross our arms. In the morning when getting dressed for the day, we tend to put the same leg in our pants before the other day after day.

Viewing the world as a physical therapist, the side of an injury matters. I will treat a left shoulder injury different than a right. Likewise, right hip, knee, and foot issues will initially be treated differently than if the left side were affected. They often have different causes and symptoms. Left sided non-traumatic injuries tend to be more chronic, right side tends to be more acute. That is, left sided pain is at a lower level and in general takes longer for a person to seek medical attention. Right side pain is more intense and people will come in sooner. Right sided issues seem to get resolved quicker than left.

I recently had the chance to implement a graded imagery program with a patient. It is used primarily with patients with chronic regional pain syndrome (CRPS) and people with phantom pain (when someone loses a limb, they often experience pain where the limb once was). A graded motor imagery program begins with exercises to practice left vs. right discrimination. People in chronic pain often lose the ability to identify left or right images of their painful body parts. They are slower and less accurate than someone without pain determining whether an image is left or right. During this phase of the intervention, the patient is shown images of left and right sides of the body and asked to determine if the image is left or right.

Can you identify if this is a left or right hand? A person with chronic or phantom pain may have a hard time identifying if this hand is left or right
Can you identify if this is a left or right hand? A person with chronic or phantom pain may have a hard time identifying if this hand is left or right

After the lateralization phase, they then go in to the motor imagery phase. This is where the patient thinks about moving the painful extremity without actually moving it. This can be difficult if you are in pain. By imagining movements, you use similar brain areas as you would when you actually move (like the Matrix!). After this stage, the person is ready for mirror therapy. The patient puts the painful limb behind the mirror and watches the reflection of the uninjured limb move in the mirror. The mirror essentially tricks the brain into thinking that the painful hand is ok and moving without pain. You are now exercising the painful limb in your brain. By exercising this area of the brain, the sensitivity in that limb decreases as the brain realizes that the limb must be ok since it is moving without pain (when, in fact, it is seeing the reflection in the mirror).

The idea of an intervention like this is to decrease the influence our central nervous system is playing on our pain. Often times there may not be anything physically wrong with an injured body part, but our brain is over-reacting to the pain as if there is significant harm to body. Just like in the Matrix, in which the machines alter the nervous system of the humans to trick them into a false reality, our brains can overreact to stimuli and perceive false pain.

We are living two different lives. Not reality and the matrix, like Neo has to deal with, but rather, left and right. Morpheus often reminds Neo to “free your mind”. We often need to free our minds and consider left and right sides of our bodies and our lives. Our world is inherently asymmetrical and we must appreciate this in order to find balance and equilibrium.


This blog post was written by Craig Depperschmidt

The Matrix

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