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Graded motor imagery — the use of a sequence of laterality reconstruction, traditional motor imagery and mirror box therapy — is gaining ground in physical therapy practices for its effectiveness in treating chronic pain patients. The theory is that there is a high degree of overlap in the brain regions involved in imagined and actual movement, so imagined movement can lead to actual movement.

"It's pretty exciting to be involved in a breakthrough," said John Hoops, PT, site coordinator at Sister Kenny Sports & Physical Therapy Center in St. Paul, Minn. Hoops has been using graded motor imagery for about two years on patients suffering from complex regional pain syndrome. "It's nice to have a new tool," he said.

Hoops said he decided to try graded motor imagery on his patients because of mounting evidence that the modality is effective. Most of his patients have tried multiple therapies and have been dealing with pain for at least several years. "We've found it quite useful, especially considering we didn't get many good results before with what we tried," he said.

How it works

"We know in people with pain — in a hand, foot or back — that body-part representation is mixed up in their brain," said Adriaan Louw, PT, MAppSc, GCRM, CSMT, founder of the International Spine & Pain Institute in Story City, Iowa. "Graded motor imagery is a series of exercises to re-establish [the correct] image in the brain."

The number of sessions varies, depending on the longevity and severity of pain. Typically patients can complete the three phases in about six weeks, visiting the therapist three times per week and performing homework, Louw said. The therapy doesn't involve drugs, injections or surgery.

"The therapist can take someone with some of the most severe pain on the planet, take them through simple, little routines and reverse the neuropathic pain quite a bit in a short matter of time," Louw said. "These are the worst of the worst cases, people who have gone from pain clinic to pain clinic. If you can offer someone significant relief in three to four weeks, we think that's pretty amazing."

Although some psychologists are trying the technique, the knowledge of movement, physiology, biology, the merger of neurology and orthopedics, and an understanding of pain make PTs imminently qualified to use graded motor imagery, Louw said.

In addition to chronic pain patients, Louw has used graded motor imagery with joint replacement patients, having them watch people actively bending the joints. The patients become able to move their new joints more easily with this therapy.

Sequential phases

The first phase is laterality reconstruction, restoring the ability of the patient to identify images of the left and right sides of the body accurately and quickly. Normally people easily can identify a left or right hand or foot, but pain patients have more difficulty recognizing painful extremities. Hoops said he tests pain patients' laterality recognition using a computer program. They recognize correctly only about 80% of the time, he said.

The average person will be able to correctly identify an extremity in 2.4 seconds, but a patient with persistent pain will take twice as long to correctly distinguish between left and right, Louw said. "The more this is messed up, the more pain they have," he said. "We take them through a series of exercises to correct left and right. The pain eases drastically, the swelling goes down and the ability to use the arm [or leg] gets better."

To correct the faulty perceptions, the therapist shows the patient pictures of a left or right extremity, matching it to the painful body part. The Neuro Orthopaedic Institute in South Australia sells flash cards with images of extremities or the back in different positions, which the patient can practice with, and an online tool to help with recognition. However, Louw suggested patients look at magazines, circle the extremity and train their brains to recognize left and right in the photos. The patient can cut out pictures themselves and attach them to index cards to create their own flash cards at little cost, he said.

Hoops asks patients to practice at least four times per day, but eight times per day has been shown to be most successful.

The closer a patient gets to the time in which the average person can identify left or right, the less pain the person experiences, Louw said. As with other physical therapy, patients increase the repetitions and image complexity of laterality recognition, he said.

In the second phase, traditional motor imagery, the patient watches someone else performing what the patient would find to be a painful action, or thinking through performing the action themselves without actually moving. "It exercises the synapses associated with that activity," Louw said.

Hoops has patients imagine an activity that is meaningful to them. For example, he had a patient who liked to fish envision casting with the painful arm.

Mirror therapy is the third and final component of a graded motor imagery sequence. The patient places the painful body part in a box behind a mirror. The functional extremity remains outside, reflected in the mirror attached to the box, presenting a reverse image of the body part to the brain. This method tricks the brain into believing the painful body part is moving freely. "We are building back strength and normal muscular control from the cerebral cortex down to the arm or leg," Hoops said.

Mirror boxes can be purchased from NOI or they can be made with a sturdy box and a mirror.

Therapists charge the same amount as other therapeutic activities for graded motor imagery, and medical insurance typically covers the sessions, Louw said.

The biggest risk associated with graded motor imagery is that it might not work, Louw said. Some patients may have increased pain if they begin using the body part more.

"The more I learn about this, the more I'm beginning to appreciate how complicated our brains are," Hoops said. "I think one reason graded motor imagery has evolved is that neuroscience has improved so much in the last 10 years."

Researchers now are investigating the use of graded motor imagery for acute injuries, such as ankle sprains. "All of the changes in neuroscience are helping us understand the brain better and giving us insight. Who knows where we will be in 15 years," Hoops said. •

Debra Anscombe Wood is a freelance writer.