A Huge Step in Advancing Pediatric Orthopedics

Chang Frank-008
Dr. Frank Chang

The Gait Lab is among the top five most advanced labs in the world

In July of 1999, Children's Hospital Colorado opened the first and only gait lab facility for kids and adults in the Rocky Mountain region. Today, our Center for Gait and Movement Analysis (Gait Lab) is among the top five most advanced labs in the world, and our pediatric orthopedic program is ranked among the top three in the nation.

The Gait Lab, one of the few areas in our hospital used both by children and adult patients, is a state-of-the-art facility led by director of the lab Dr. James Carollo, PhD, and co-medical directors Dr. Dennis Matthews and Dr. Frank Chang. It's staffed by a multidisciplinary team of highly trained, passionate and innovative professionals.

Dr. Frank Chang, also co-founder of Gait Lab, is a world-renowned specialist in cerebral palsy. His work has helped make the use of a gait lab standard protocol in treating these patients, across the U.S.

Changing the standard of care

"My interest in computerized gait analysis started about 18 years ago, after observing how the Olympic Freestyle Ski Team was using technology to assist in understanding complex motions in athletes," said team physician Dr. Chang. "I knew using instrumented gait analysis for my patients would greatly improve outcomes. I was excited."

This technology promised to radically change the treatment of gait disorders in patients where, "even the littlest difference can change a patient's entire life," explained Dr. Chang.

The old way

Before gait labs, clinicians relied on observational assessment and static physical exams, which alone couldn't adequately reveal the functional causes of a particular gait abnormality.

"We'd feel their bodies, watch them walk, and then make decisions on how to correct the problems," said Dr. Chang. "You did not always know which muscles were firing, or how much force was generated. It was impossible to look at bilateral hips, knees, ankles, legs, and feet all at once, or to assess which muscles were strong or weak as the child was walking."

Typically, patients would undergo a surgery at a different level each year—subjecting them to the risks associated with surgery and the need for rehab over and over. "What's more, until the gait lab, there was no way to get accurate, objective data on these kids, or to measure how a treatment plan worked. Or didn't," explained Dr. Chang.

How it works now

Our Gait Lab generates measurable data—detailed, quantitative information about walking patterns—using six fundamental measurement technologies:

  • Slow motion video analysis captures multiple digital images of a patient’s motion from the front, back and both sides, using advanced video recording techniques. Digital Images can then be studied frame by frame.
  • 3D motion kinematics precisely records three-dimensional limb movement by capturing the angular displacements, velocities and accelerations from the sagittal, frontal and transverse planes of multiple joints simultaneously. Computer software calculates the center of joints and the orientation of each limb segment in space, generating precise, 3D joint motion data. This data is compared to graphs of normal data to identify unusual patterns and the magnitude of variation.
  • 3D motion kinetics is the physical forces that produce joint movement while walking. Specifically, the ground reaction force is measured using custom force platforms imbedded in the floor. Combined with kinematics data, this information allows the team to fully describe the biomechanics of movement and distinguish a patient's gait abnormalities from compensatory movements.
  • Dynamic Electromyography records the electrical activity and activation patterns of 16 muscles simultaneously, as the patient walks. It's the only method available to determine the timing of muscle movement and provides important information about the functional cause of movement abnormalities, especially important in those with neuromuscular disorders. Wireless electromyography markers are our newest addition.
  • Temporal distance measures are the average walking velocity, cadence, stride length, gait cycle time, and double and single limb support time.
  • Pedobarographs record the plantar pressures of both feet dynamically while walking.

From lab to treatment

Once gathered, data from all six technologies combined with appropriate history and a comprehensive physical and neuromuscular exam is compiled and compared against a range of normal data.

"A program called Polygon organizes everything on one big screen. There's graphs and tables and numbers, but also an actual video of the patient walking viewed from the front and side as well as a computer-generated 3D model we can manipulate and study from different perspectives," said Dr. Chang. "This allows us to look at every part of the body all at once. And to really see what's an issue, what's a compensatory movement and how far from 'normal' everything is."

Then together a team of rehabilitation physicians, pediatric orthopaedic surgeons, physical therapists, kinesiologists and biomedical engineers recommend a course of treatment, targeting a patient's specific problems, with overall functional gains as the desired outcome.

Most notably, having precise data allows doctors to plan a single, multilevel surgery to correct all the issues at one time, and create a year-long plan that helps kids achieve a more functional gait pattern. This plan "may also include physical therapy, phenol or Botox injections, or orthotic prescriptions," said Dr. Chang.

While a single event surgery may include 5-10 different procedures—sometimes lasting more than 10 hours—and a single recovery can be harder on the patient and doctors, the outcomes are greatly improved. "No one else in our area can do this," said Dr. Chang. "In fact, few in the world can."

Since The Gait Lab first opened over ten years ago, there has been a strong and consistent desire by the medical, clinical and technical teams to continue the tradition of weekly data reviews for all patients seen at the gait lab. This commitment to a traditional clinical lab practice is unusual, explains Dr. Carollo.

"This is how most clinical laboratories began, but few continue this practice because of the cost and scheduling difficulty of having so many professionals together for four hours each week. We continue this practice because we feel it provides the most beneficial and individualized treatment plan, enhances patient care, and has contributed to the consistently great outcomes we see in patients with movement problems"

Making a bigger difference

Part of what Dr. Chang loves about the Gait Lab is that it's making a huge difference in the lives of his patients—a huge theme in his own life. Having the technology to provide the most accurate analysis, a team to work together to develop the most effective treatment plans and the ability to objectively evaluate each patient's progress has changed how orthopedics and rehabilitation is practiced.

"We currently have nearly 20 ongoing research studies, all of which have the potential to continue to improve how we treat kids with gait disorders. And none of which would be possible without the Gait Lab."

That continual improvement is what drew Dr. Chang to Children's Hospital Colorado and pediatric orthopedics in the first place. "When I entered the field," he said, "I chose a direction that would include teaching and research. I wanted to make the biggest impact I could. I work hard to have great relationships with my patients and their families. But I also encourage my students to do things the best way and to look for ways of doing everything better."

A well-rounded program

As amazing as the Gait Lab is, our orthopedic program also places an emphasis on the importance of mental health and physical activities to benefit the whole child. Our Hospital Sports Program, possibly the very first in the nation for kids with physical disabilities, began over 40 years ago and serves as a model for programs worldwide.

Dr. Frank Chang

Director of Orthopedic Surgery
Co-Medical Director: Center for Gait and Movement Analysis
Medical Director: Hospital Sports Program
Children's Hospital Colorado

Children's Miracle Network/Helppie Family Chair in Orthopedic Movement Analysis

Professor of Orthopedics Surgery, Rehabilitation Medicine and Pediatrics
University of Colorado School of Medicine

Dr. Chang received his medical degree from St. Louis University in 1975, completing his internship in general surgery and his residency in orthopedic surgery there as well. He went on to do a fellowship in pediatric orthopedics at the Alfred I. DuPont Institute.

In 1981, Dr. Chang joined Children's Hospital Colorado and has been winning over patients and families with his great sense of humor and endless supply of colorful stamps and gummy worms ever since. He holds a chair in Orthopedic Movement Analysis, is a Professor of Orthopedic Surgery, Rehabilitation Medicine and Pediatrics at the University of Colorado School of Medicine and currently is serving as president of the Gait and Clinical Movement Analysis Society. He is sought after worldwide as an informative and entertaining speaker.