| The News Tribune | 01/30/13 03:47 |
Just two years following a diagnosis of cerebral palsy at Seattle Children’s Hospital, Cody Marmon took his first independent steps. He was 3 years, one month and one day old.
“It was really exciting to watch,” said Tina Marmon, Cody’s mother.
Dr. David G. Embrey, the research program coordinator at MultiCare Good Samaritan Children’s Therapy Unit, witnessed Cody’s first steps along with Tina. About the same time, Embrey monitored Cody’s muscle movements and compared them with his brother’s muscle movements, utilizing an innovative technology called Surface Electroymyography (SEMG).
The technology, designed and manufactured by Noraxon, gives doctors an ability to place sensors on the top of the skin and record electrical signals from the brain that fire to make muscles move.
“The first time I went inside the body of a child with SEMG, I was absolutely astonished,” Embrey said. “The body was not functioning at all like my eyes were telling me. I’ve now been able to take the technology and change what I do in treatment to become more effective.”

Dr. David Embrey demonstrates the placement of a wireless sensor and its attached electrodes last Wednesday.
Embrey and his colleagues at Good Samaritan Children’s Therapy Unit recently were featured in “Health Heroes” on The Discovery Channel. The documentary explained how Embrey used SEMG to guide Cody’s treatment.
“Over time, we used SEMG to change the way Cody’s muscles work during functional skills like standing, walking, running and riding his tricycle,” Embrey said. “SEMG enabled us to see Cody’s muscles contract during functional movements and select the best treatment to help him move better.
“Cody practiced his functional skills like riding a tricycle and learned reciprocal contraction for his legs,” he added. “We used SEMG to determine the best application of Botox to minimize the spasticity in his leg muscles.”
Embrey said Cody received Botox, first for his calf muscles for six months, then for his hamstrings for the second six months.
“With less spasticity in the calf and hamstring muscles, we changed Cody’s braces to allow movement at his ankles,” the doctor said.
Today, Cody is in his early teens, and his mother said there is a huge difference when he walks.
“When he runs, you can notice,” Tina Marmon said. “But he is far and above anything we could imagine. He’s amazing.”
When Cody was 8, he had muscle-lengthening surgery in his right foot, the right-side hamstring and both Achilles’ tendons. After that, Cody’s mother said he had a two-year recovery of learning how to walk.
“Cody does a lot of exercises to stretch his muscles,” Tina said. “David (Embrey) watches him very closely. He is a second set of eyes. A lot of times, I wouldn’t notice the tiny subtle differences. As a parent, having David 15 minutes away from us has been great. If I have any questions, I can bring Cody in. He’s always been right there for our family.”
As a result of using SEMG, Embrey, along with Sam Augsburger, the director of the Motion Analysis Laboratory at Shriner’s Hospital for Children in Lexington, Ky., came up with a prototype for a new device called the Gait MyoElectric Stimulator (GMES). The device helps stroke victims walk again by sending signals from a patient’s strong foot to trigger electrical stimulation for the muscles of the opposite weak leg.
On Aug. 31, 2004, Embrey came up with the idea as he was analyzing the SEMG data of Cody and his brother.
“SEMG data revealed the perfect timing pattern to stimulate the muscles with the GMES in the lower leg during walking,” Embrey said. “Our electrical stimulation system provides contraction in the shin muscles to lift the foot when it is in the air and stimulates the muscles to propel the body forward during the stance phase.
“SEMG has also helped refine the timing mechanism and validate the muscles are contracting at precisely the correct time during the walking cycle.”
In 2010, Embrey published a study to test the device. The research tested 28 adults who had physical impairments. His findings were presented at the Movement Performance Institute in Los Angeles and also published in the Archives of Physical Medicine and Rehabilitation.
The research was funded with a $200,000 grant from the Hillard Trust. Florence Hillard, who died in 1975, dedicated a portion of her trust to stroke research at Good Samaritan after the hospital took care of her brother.
Embrey received a U.S. Patent on that first prototype and recently has come up with an advanced prototype called the GMES II.
The research team to develop the new prototype includes Jeff Stonestreet, a Boeing electrical engineer, and Gadi Alon, Ph.D., a tenured professor of physical therapy at the University of Maryland.
The new technology stimulates any muscle in the leg, arm or trunk at the correct time according to established patterns for normal walking.
Last October, Embrey filed for a U.S. Patent on the GMES II. He and his business partners are seeking national investors who are interested in marketing the device. Embrey hopes that exposure on The Discovery Channel will help that effort.
“It will bring the knowledge of the technology to market,” he said.


Most treatments for cerebral palsy (CP) are initially directed toward children. What is not clearly established is the long- term effects of such treatments. Many appear helpful in the short term but prove to be disadvantageous in the long run. Selective dorsal rhizotomy (SDR) is a permanent, irreversible neurosurgical procedure for reducing spasticity in cerebral palsy. Parents contemplating SDR for their child would like assurance that that there will not be harmful complications from it as the child ages into adolescence and adulthood. We now have new evidence...







