Dynamic Brace Beats Post-Polio Boomerang

By Miki Fairley

When a 72-year-old retired physician with post-polio syndrome (PPS) presented at Prosthetic Orthotic Associates (POA) in 2008, he was unable to ambulate and used a scooter for mobility. He suffered from left knee pain, medial and lateral knee instability, genu recurvatum, and low endurance.

He now can walk, clean the swimming pool, and help his wife with household chores and meal preparation.

Another PPS patient previously had a difficult gait and could walk for only about 10 minutes before becoming exhausted. After treatment, she called David Guy, MS, PT, and said, "Guess where I walked today? I spent two hours in the grocery store and then drove to Kohl's department store and spent another two hours. I was on my feet for four hours—and I'm not tired!"

Guy

"We're seeing similar results with all our post-polio patients," Guy says.

These are not instant, miracle cures, but rather the result of a unique combination of innovative orthotic design, an exercise program, and highly motivated patients. This combination has resulted in astonishing improvement for these patients, along with some unexpected results.

The unexpected aspect is that the treatment not only provides joint stability and less energy expenditure but it also appears to provide motor and sensory input. This input is thought to stimulate the production of cytokines, neurotransmitters which stimulate muscles, causing them to work again after many "dead" years.

Cytokines are proteins, polypeptides and glycoproteins, Guy explains. "They act as neurotransmitters that are secreted by specific cells in the immune system. They then carry signals locally between cells. It is our belief that the DBS causes these cytokines to be released by the immune system, and the result is the increase in muscle activity."

Guy and Sander Nassan, CPO, FAAOP, owner of POA, have performed extensive testing to monitor patients' progress and verify results via electromyographic (EMG) and manual muscle testing along with cardiopulmonary testing.

The Program—a Closer Look

Loke with the Dynamic Brace. Photographs courtesy of Dynamic Bracing Solutions, San Diego, California, and Prosthetic Orthotic Associates, Scottsdale, Arizona

The orthotic technologies used by Nassan and Guy were developed by Marmaduke Loke, CPO, and Jean-Paul Nielsen, CP, owners of Dynamic Bracing Solutions Inc., San Diego, California. The technologies are based on concepts Nielsen developed and taught in the early 1990s along with Loke's innovative ideas and experience.

Guy and Loke presented a case study by the retired physician during the 2009 American Orthotic & Prosthetic Association (AOPA) National Assembly, and Guy and Nassan have submitted the study to a peer-reviewed journal. "Results in the case study and other data suggest that the accepted neuropathology of polio might need to be reexamined," says Guy, who would like to see a larger-scale study undertaken.

Guy believes it is the combination of the Dynamic Bracing Solutions (DBS) orthotic technology and the exercise program that has stimulated the regaining of muscle strength and function thought to have been permanently lost. He says that he has not seen similar results with the exercise program used with other types of orthoses, and even though the DBS orthotic system has produced some striking results on its own, it has not had the same neuromuscular recovery effect without the exercise program.

"The exercises and the brace are producing, first all, stable walking, the return of muscle strength in muscles that haven't worked in many, many years, and an increase in endurance," Guy says. "But most importantly, people who were dependent are becoming independent."

PPS—What Happens

Polio survivors often think that all the damage the disease will cause has already occurred. Then, as they get on with their lives, the boomerang—new or worsening symptoms—strikes many years later.

The National Institute of Neurological Disorders and Stroke (NINDS) of the National Institutes of Health (NIH) defines post-polio syndrome as a condition that affects polio survivors years after recovery from an initial acute poliomyelitis virus attack. PPS is mainly characterized by new weakening in muscles that were previously affected, as well as muscles that seemingly were not affected although some PPS patients experience only minor symptoms. Symptoms include slowly progressive muscle weakness, unaccustomed fatigue, and sometimes muscle atrophy. Pain from joint degeneration and increasing skeletal deformities such as scoliosis are common. Researchers estimate that PPS affects 25-50 percent of polio survivors, or even as high as 60 percent, with some 440,000 survivors at risk in the United States.

The cause is unknown although NINDS notes that the new weakness of PPS appears to be related to the degeneration of individual nerve terminals in the motor units (neurons and the muscle fibers they activate) that remain after the initial illness. The poliovirus attacks specific neurons in the brainstem and the anterior horn cells of the spinal cord. To compensate for the loss, surviving neurons sprout new nerve terminals to the orphaned muscle fibers, resulting in some recovery of movement and enlarged motor units.

"Years of high use of these enlarged motor units adds stress to the neuronal cell body, which then may not be able to maintain the metabolic demands of all the new sprouts, resulting in the slow deterioration of motor units," NINDS theorizes. "Restoration of nerve function may occur in some fibers a second time, but eventually nerve terminals malfunction and permanent weakness occurs. This hypothesis is consistent with PPS's slow, stepwise, unpredictable course."

If this hypothesis proves correct, how the treatment program implemented by Guy and Nassan may be involved in regaining muscle function could provide a promising area for future research.

Exercise Program

In developing the exercise program, Guy explains, "We treated the brace as though it were an artificial limb. With an artificial limb, first we concentrate on stabilizing the trunk, so the patient has a stable platform from which to move the limb. We then work on stabilizing the hip joint, and then we move down the leg to the knee and the ankle. The exercises are in four stages and start off very slowly and gradually increase."

Post-polio patients often have learned to walk in particular patterns to compensate for various weaknesses, deformities, and balance issues. These patterns often become automatic but are inefficient, energy-consuming, and can even add further stress and damage. "Getting people to take the risk of doing something that caused them to fall in the past is extremely difficult," Guy says. "Helping them to break these old habits is probably the biggest challenge we face."

DBS: Concepts behind the Technology

The main concept behind the DBS technologies is "true triplanar orthotic management," Loke says. "A skeleton comprises three dimensions, and we need to manage musculoskeletal structures in all three dimensions. Most AFOs—both custom and prefabricated—often only partially manage the sagittal and coronal planes. Very rarely is the transverse plane considered with traditional designs."

Loke's goal is for orthotic users to be able to achieve the same ease and smoothness of walking that many persons with amputation accomplish. Gait that is closer to normal translates into less energy expenditure and physical strain, enabling the patient to have a better quality of life both physically and psychologically.

Loke is well-versed in gait training. He began his career in a children's hospital, where he "gait-trained about 10 kids every day for several years," he says. "When I entered the O&P field, I noticed a lack of orthotic education to enhance function of ambulation with lower-limb orthotics. Because of my experience, I had a good understanding of how the 'bio' and the 'mechanical' work together—the patient working with the device for better outcomes."

Even before the development of the DBS exercise program, Loke, Guy, and enthusiastic DBS orthosis user Marny Eulberg, MD, a polio survivor, have strongly stressed the importance of an almost symbiotic relationship between gait training and the orthotic technology.

Loke says he spends hours studying gait videotapes of his patients. "I use a videotape of patients' gait to find out what their deficiencies are in each dimension and develop a walking solution to counter that, looking at issues such as balance, security, mobility, and alignment. It's very meticulous and time-consuming." Loke videotapes patients before designing and fitting the graphite composite orthoses as well as during fitting and often during follow-up.

Some of the concepts now used in DBS orthotic technology are discussed in a paper by Nielsen and Deanna J. Fish, MS, CPO, FAAOP, titled "Clinical Assessment of Human Gait," published in the April 1993 issue of the JPO. "Functional activities of daily living rarely occur in one plane; therefore, motion can be described as triplanar or occurring in all three planes simultaneously," the authors note. Nielsen and Fish discuss the external rotary and the internal rotary patterns of motion in the transverse plane and their role in orthotic evaluation and design. Medial or internal rotation refers to rotation toward the center of the body. Lateral or external rotation refers to rotation away from the center of the body.

"The ability to walk efficiently is based upon the proper alignment of the bones of the feet, which in turn affect the alignment of the ankles, knees, and hips," Loke notes on the DBS website (www.dynamicbracingsolutions.net). "Muscle strength from above is also a factor. Weak or missing muscles create abnormal rotational patterns causing malalignment of the joints below. An effective brace must provide for triplanar control of the foot and ankle while providing triplanar support for weak muscles. It must work from the ground up and the top down simultaneously."

Marny Eulberg, MD, DBS Enthusiast

Eulberg

Eulberg's experiences with post-polio and the DBS bracing system are enlightening. Named Colorado Family Physician of the Year in 2005 by the Colorado Academy of Family Physicians (CAFP), she conducts a post-polio clinic at St. Anthony North Family Medicine Center, Westminster, Colorado. Before trying a DBS orthosis, Eulberg had been using an AFO that controlled her foot drop and provided some knee control. She used a single forearm crutch when walking more than one block, such as when making hospital rounds.

However, she was experiencing increasing quadriceps weakness and feared that her knee would buckle and she would fall. "I thought my only option was a long-leg brace with a knee lock, and I wasn't crazy about that," she recalls. "It's very inconvenient to have to lock or unlock the brace every time you stand up or sit down, and the joint usually chews up pants like crazy." Eulberg also worried that she had enough hip flexor strength to manage the weight of the brace.

Then a patient came in for a re-evaluation, displaying a striking improvement in her gait after being fitted with a DBS orthosis. Eulberg decided to try one for herself and has been delighted with it ever since. "I walk hands-free, only using a cane occasionally in very uneven terrain."

In fact, she was so happy with the brace that she asked Loke to make her another one as a backup. "I didn't want to be without it for a few weeks if it broke." Eulberg describes an unexpected benefit: "I felt so much better about myself and had so much more energy that I was motivated to lose 50 pounds." Then, because of becoming slimmer, she needed a third orthosis for a snug fit.

Does Eulberg recommend DBS orthoses to her patients? "It depends," she says, "on things such as how they present physically, their financial resources, and their motivation."

Eulberg echoes Guy on the importance of patients' motivation. "When people start with the DBS brace, something happens that doesn't often happen in the traditional orthotic world—and that's gait training, which is a real challenge. Patients have to unlearn gait patterns they've been using for perhaps 50 years. Walking is so automatic. Unlearning a pattern that has basically become unconscious takes a lot of work and can be frustrating."

Eulberg still sees a physical therapist about once a month, noting that "it's so easy to backslide." She has started a closed DBS users' group on Facebook as well as a group that meets about every six months to exchange advice and experiences. She is one of the instructors at an upcoming DBS Orthotic Triplanar Basic Course in Scottsdale.

Besides DBS, other innovative orthotic technologies, such as electronically controlled stance-control knee joints, are emerging for post-polio patients and others with neuromuscular and musculoskeletal pathologies.

New Technology Considerations

Mark Taylor, MLS, CPO, FAAOP, University of Michigan, Ann Arbor, who has presented at various conferences and published papers on PPS, is enthusiastic about the new technologies, but points out some caveats.

"With new componentry and materials, we have more choices than ever before," Taylor says. "But with this new technology comes more responsibility to our patients. We don't want to put patients at greater risk." Practitioners also have a greater responsibility to their physician referral sources, Taylor adds. With the knowledge explosion in their own fields, doctors are relying more on O&P practitioners and physical therapists to make sound recommendations for devices and therapy.

How can orthotists/prosthetists best keep up with new technological advances? "New technology comes with lots of questions," Taylor says. "Ask colleagues who have worked with the technology you're considering, read whatever literature is available, talk with the manufacturers—gain as much knowledge in every fashion that you can."

New technology doesn't work for everyone, Taylor points out. Considering such issues as the patient's environment and motivation is important. For instance, a technology that works fine in an indoor or city environment could be a poor choice for a farmer working with livestock and crops in a totally different environment. Finding the right candidates—or developing the right candidates through training and physical therapy—can be difficult. "You can't just put new technology on someone and say, 'See you in six months.'"

Future Visions

Appropriately used, new orthotic technologies are opening up new vistas of function and quality of life for post-polio patients as well as others. What could the future hold?

Guy, for instance, is envisioning using DBS technology for children with cerebral palsy. "We could help them not only maintain strength and balance, but also overcome distracting gait movements that cause social stigma and psychological issues. We could help these kids to have better lives both physically and psychologically."

Loke is enthusiastic about the outcomes experienced by the network of DBS clinicians. "I believe most people needing lower-limb bracing can benefit from technologies with triplanar management and dynamic response because deformities can be prevented and often corrected, surgeries minimized, muscles stimulated to enhance strength, and, most of all, quality-of-life issues improved.

"We now have several active-duty wounded soldiers regaining a very high level of activity needed for redeployment," he continues, "and post-polio patients around the world can see great promise with bracing solutions that can offer benefits beyond what was once thought possible."

Miki Fairley is a freelance writer based in southwest Colorado. She can be contacted via e-mail at