Graded Motor Imagery

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Dec 23

What is Graded Motor Imagery?

Graded Motor Imagery (GMI) is a rehabilitation program that is based on science and clinical trails to treat many complex pain and movement problems (1).

What does the GMI program consist of?

The GMI program is broken down into three unique stages of treatment techniques, with each training the brain in differing ways (1). The first stage is left-right discrimination. Simply put, this is the ability to identify left or right images of their painful body part(s) (1).

The second stage is the explicit motor imagery stage (1). This stage is essentially thinking about moving without actually moving (1). Imagined movements can actually be hard work if you are in pain. The theory behind this thought process is that roughly a quarter of the neurons in your brain are “mirror neurons” which start firing when you think of moving or even watching someone else move (1). Therefore, by imagining movements, you use similar brain areas as you would when you actually move (1). This is why athletes imagine an activity before they do it, for example, free throw shooting in basketball, penalty kicks in soccer, or batting in baseball (1).

The third stage is known as the mirror therapy stage (1). Within this stage, a mirror is utilized to trick the brain (1). For example, if you were to put your left hand behind a mirror and the right hand in front, you are tricking the brain into believing that the reflection of your right hand within the mirror is actually your left hand (1). Therefore, you are now exercising your left hand in the brain, particularly if you start to move your right hand (1).

Why does GMI work?

A neat little feature of our brains is that they are malleable. By this, I do not mean they are like a weak metal that can bend, but rather they are neuroplastic (2). Neuroplasticity is essentially the ability for one’s nervous system to change its activity in response to intrinsic or extrinsic stimuli by reorganizing its structure, functions, or connections (3). Simply put, everything we do, and everything we do not do, ultimately shapes our brains. In chronic pain patients, there are changes to the way that the brain and nervous system function. The brain and the nervous system will learn pain, and the more you experience pain, the higher chance that your pain system is stuck in a state of high-alert (2). This is known as central sensitization.

However, although neuroplasticity worked against the chronic pain individuals to have them develop this constant cycle, we can utilize neuroplasticity to break that cycle to reduce, or eliminate, their pain (2). GMI is utilized to target different regions of the brain which process and create this pain and tries to re-teach the brain to react in an adaptive way (2).

A key component of this rehabilitative program is that it is graded (2). Therefore, it simply just means that it has to be done in a step-by-step process as outlined by the three stages already mentioned. Particularly with pain patients, it is important to work at a pace that allows the patient to be abled to challenge their pain without causing a flare up in their symptoms (2). A useful tool to utilize with patients is the Shirley Ryan Abilitylab Activity Traffic Light (4). This resource clearly outlines and teaches the patient how they can constantly monitor their pain levels and their reactions to certain activities to make sure they stay within the yellow light region to challenge their pain.

As we know, pain comes from the brain. Within out brain, we have neurotags which are essentially networks of interconnected neurons within the brain (2). Therefore, when these neurotags are activated, they can create a sensation or an experience (2). When it comes to pain, these neurotags will send signals through our nervous system to tell the body when and where pain should be felt across the body (2).

However, when chronic pain develops, these neurotags become sensitized to pain (2). Which ultimately means that, they become more likely to produce pain signals and will continue to do so without inhibiting it (2). This overreaction of the neurotags will result in persistent pain (2). A big caveat with chronic pain patients or chronic pain rehabilitation is that educating an individual on the fact that the pain comes from the brain does NOT imply that the pain they are experiencing is NOT real or NOT valid (2).

GMI is graded in two ways. The three stages are graded in order of completion as Dilek et al explain that these stages are designed in such a way “to optimize sensory-motor processing to gradually engage the cortical motor networks without triggering the protective pain response” (5). The second way it is graded is to manage the symptoms of the patient to not get any flare ups, and the previously discussed resource is a good way to monitor the progress (2).

The three stages – in depth.

Left/right discrimination

When individuals are experiencing chronic pain, the mental map we have of our body becomes distorted (2). When someone who experiences chronic pain looks at images of parts of their body, they react much more slowly and less accurately when they are trying to decipher which body part belongs to the left side and which belongs to the right side (2). Therefore, before the individual can move onto the next stage of imagination, they must be able to discriminate between the left and right sides of their bodies through images (2). Typically, flash cards or pictures are utilized during this stage. However, with the advancement of technology, computer programs and even handheld applications are now available (2).

Explicit motor imagery

As we discussed previously, when we imagine our body move in a specific way, the same neurotags are activated for that specific movement as when you are actually performing the movement 2 . Therefore, even imagined movements can cause pain (2). Since it is imagination, not actual movements are performed (2). Therefore, this stage typically begins with the individual learning how to practice deep visualization relevant to the affected area (2). This portion is also graded, meaning that, the beginning stage will start from a movement that causes minimal pain. If the movement activates the pain neurotags during the imagined movement, then the therapy will focus on a smaller movement with less pain or make the therapy session shorter in duration (2). This will ensure that the therapy is not overwhelming and more tolerable (2).

For example, patient A experiences pain when walking across the room (2). GMI will help the patient to imagine getting up from a seated position (2). Then once the brain is taught that this action should not be causing pain, the imagination can extend to moving your legs, to walking forward, and progressively continue until you imagine yourself crossing the room (2). Once the brain learns through its neuroplastic capabilities that this movement should not be painful, many patients will be able to walk across the room pain-free (2). The explanation is that your brain and the nervous system has learned that the protective pain mechanism is not needed for this action (2).

Mirror therapy

Within this stage, the utilization of a mirror is necessary as mentioned previously (2). Interestingly, mirror therapy activates the brain less than true movements, but more than imagined movements (2). Therefore, this is why it is the final stage (2). Once these three stages are completed, the patients can move onto performing the movements that have been problematic (2).