Below is a blog post I wrote for the American Academy of Orthopedic Manual Physical Therapists. I am the Fundraising Chair for the Student Special Interest Group, and one of our duties is to compose relevant material for the group’s blog.
The Basics of Graded Motor Imagery
Depending on how far along you are in your curriculum, you have probably heard words like “cortical reorganization,” “central sensitization,” and “mirror training.” You may have had some lectures that addressed pain, central sensitization and graded exposure to activities. You may have even seen the wonderful G.L Moseley’s research into Graded Motor Imagery (GMI) and its application to patient’s with CRPS, phantom limb pain, and chronic pain. If you are like me, however, you never got the full picture of how to clinically apply GMI to a live patient with real, chronic, centrally mediated pain.
We are probably all familiar with Penfield’s homunculus and its simplification of cortical representation in the both the motor and somatosensory cortex.
Research has shown that in chronic pain states, the cortical representation of the affected body area becomes “smudged” and the brain has a distorted view of the area. Even small activation of these areas can be very painful for patient. This plays heavily into the manner that patients with chronic pain typically describe their pain. “Diffuse,” “poorly located,” “has a mind of its own.”
This knowledge of cortical reorganization becomes important when educating patients with chronic pain in that their pain is not necessarily related to any tissue damage. It is a hard concept to get your patient to understand, and I often heard “Oh, so the pain is all in my head.” I highly recommend getting your “pain talk” down so that patients are able to digest this information without feeling like their pain is somehow not real.
GMI was designed specifically to address this cortical reorganization and other processes of chronic, centrally mediated pain. According to the Neuro Orthopaedic Institute (NOI), “GMI is a sequence of strategies including laterality restoration (being able to identify left and right limbs), motor imagery and use of a mirror box.”1 It is rooted in biopsychosocial theory and addresses how pain is “lived.”
The first step to GMI is laterality training. The cortical reorganization involved in chronic pain leads to a distorted view of the limb. Laterality training determines how easily a patient can judge left/right images of their affected body part. Additionally, laterality training does not activate the motor cortex.
The training is broken down below:
- Recognise App/online
- Flash Cards
- IT DEPENDS!
- Start with 20 images with 10 seconds of time
- The patient CANNOT MOVE their hands to guess the position
- Try to get them to respond as quickly as possible
- Gauge symptoms
- It’s ok to be sore as long as you are safe
- Try to have the patient practice 4-5x per day without flare up
- Rough baseline for advancement
- 2 weeks
- Looking for roughly 80% accuracy
- 1.6s +/- .5s for neck and backs
- 2.0s +/- .5s for feet and hands
Once a patient has reached the above criteria, they are ready to start with explicit motor imagery or in easier terms, imagined movements. If you are having a hard time digesting this one, let me help. If you are in a room with a door, imagine yourself walking through that door. No problem, right? Now imagine that door is open just enough to squeeze your body through. Now try to get through the door. Did you feel yourself slide between the door and the frame? Did you maybe “feel” the brush of the frame against your back? That is explicit motor imagery. Explicit motor imagery WILL activate the primary motor cortex.
The criteria are similar to laterality training and are below:
- Start with a movement that the patient is not afraid of
- Break it down into steps
- Have the patient try it in a quiet spot
- Gauge the reaction
- If it’s painful, take a step back to left/right images or find a different movement
- 4-5x/day for 2 weeks without flare up
After achieving the above, it is time for the fun stuff! Mirror training is the last piece of the GMI puzzle. This activates the primary motor cortex almost as much as actual movement, which is why it is the last piece.
- Start slowly with the affected hand/body part in a static position behind the mirror
- Place the opposite hand/body part in front of the mirror and perform movements while focusing on the reflection of the hand in the mirror
- Start in a quiet place
- Start with 1-2 minutes and progress from there up to 5-10min daily
- As usual, take a step back in the case of flare-ups!
Here is a great progression of mirror training.
Those are the basics of GMI and here are some things to keep in mind.
- It’s ALL individualized for the patient
- You can start with any of the three progressions, but don’t get greedy!
- You may need to start with an uninvolved limb if the patient is really sensitized
- Have your patients practice in as varied as settings as possible as they progress. GRADE IT.
- Dial it back if you have flare ups and be able to make suggestions to keep moving forward
- A patient cannot harm themselves with imagery, but flare ups can only further sensitize
- “It’s ok to be sore as long as you are safe”
For more reading, I recommend the NOI website at http://www.noigroup.com/en/Home. If you really want to become better at applying GMI, the Graded Motor Imagery Handbook and Explain Pain are both available on the NOI website.
As novice clinicians, patients in chronic pain states will most likely be our biggest challenge, but this is where it all starts. In my first clinical, I brought GMI to my CI and treated several patients with aspects of it. I challenge and encourage you to do the same.
UIC SPT 2015
- Available at: http://www.noigroup.com/documents/noi-gmi-evidence. Accessed December 26, 2014.
- Moseley GL, Butler DS, Beames TB, Giles TJ. The Graded Motor Imagery Handbook. . Adelaide Australia. Noigroup Publications. 2012