The Texas Back Institute (TBI), a private multi-disciplinary spine care center headquartered in Plano, Texas, is dedicated to improving the lives of patients through research, knowledge and wide-ranging treatment approaches. For more than 40 years, the institute has integrated the best of science and education into innovative care for all types of spine conditions. Focusing on the head, neck and lumbar regions, TBI’s team of physicians can address everything from chronic lower back pain to scoliosis in adults and children. But to do so, they need as much information as possible.
Data lies at the heart of good treatment decisions, whether they are surgical or non-surgical in nature. This led TBI to build an advanced motion capture lab, supported by a generous grant supported by a generous grant from the Viscogliosi family.
The genesis of the lab began two and a half years ago at the hands of Dr. Ram Haddas, TBI’s Director of Research, and a PhD and medical engineer. Dr. Haddas saw the potential to create a research environment that not only met TBI’s demanding specifications, but would also incorporate the best technology the industry had to offer.
Even today with all the recent advancements in medical technology, there is limited research on human motion and the spine - and what does exist focuses primarily on gait. With its new lab, TBI would be able to produce research that had a big impact on the analysis and treatment of commonly performed spine surgeries done at TBI and beyond.
A dream setup
With the support of his TBI colleagues, Dr. Haddas was able to design and equip his dream lab. As a research assistant in college, Dr. Haddas became familiar with motion capture thanks to a Vicon system he encountered. The idea and its potential for the medical field stuck with him, and when the opportunity to create the lab arose he explored several solutions, ultimately deciding that Vicon outshone the competition.
The TBI system consists of ten 16-megapixel Vantage cameras set up throughout a 900-square foot lab. The setup features five cameras in the back and five in the front, alongside two Bonita video cameras, one in profile so doctors can see a patient’s gait from the side, and the other positioned in front - this particular camera is critical to assessing the pain scale. The camera records fine facial movements like an eyebrow or lip twitch, which occurs when a patient experiences pain. The camera is used as a sort of psychological test, helping to identify the correlation between pain and motion.
Pain, what patients feel and how it’s measured, is a critical part of the assessment and treatment process. It is regularly measured by a highly subjective rating system where patients rate discomfort on a one-to-ten scale, however, everyone has a different perception of pain depending on a whole host of factors. Vicon and integrated EMG data can help quantify pain and establish more objective criteria. Physicians can compare, for example, what a patient says with how fast they’re walking or their range of motion. There is a proven relationship between physical and mental states, and through Vicon data and analysis, medical teams are able to scientifically correlate the two together.
The sophisticated features of the Vantage system, including the onboard sensors within the cameras that detect excessive heat or movement, have also made the entire process simpler and more efficient. This comes in handy when someone bumps a camera, which can happen frequently in a lab environment. If this happened in the past, capture would need to stop and the whole system would need to be manually recalibrated. Now, recalibration is quick and done with a single click.
Medicine in motion
Due to its global reputation and proximity to nationally renowned medical centers in Texas, the Texas Back Institute motion lab is extremely busy. In the first year, 100 patients visited the lab, and that number doubled in the second. Patients come to obtain analysis for a wide range of issues, including degenerative disc disease, osteoporosis, spinal stenosis, fractures and sacroiliac joint pain. Candidates for surgical procedures generally undergo testing one week before their operation for a baseline study, then return for a short-term follow up. They then finish with a final visit about a year after surgery.
Rather than focus on treadmill analysis patients walk freely in the lab, as it more accurately mimics real-world movement conditions. Surgery is traditionally based on static imaging, but as soon as patients start to move, things change. The Vicon system allows physicians to see precisely how patients enter their gait cycle, and it enables analysis of joint angles and movements. When the spine is engaged the lumbar, neck, thorax and head can all be affected.
A full-body marker set includes a total of 41 markers. The TBI surgical team has also developed a spine model, adding nine additional markers. Once cameras are calibrated, the team collects data on gait, speed and cadence, measuring every joint angle - including the ankle, knee and hip – in three dimensions and at 300 frames per second. Electromyography (EMG) data measuring electrical activity produced by the muscles is also fully-integrated within the Vicon software platform. That provides physicians with a full picture of how much muscle energy a patient is expending in the gait cycle, the degree of swing in lumbar balance tests, lifting and balance details and more.
With height, weight and other measurements, the team can also calculate a patient’s exact center of mass and displacement. During a one-minute test, physicians can track the extent of displacement of the center of mass of a scoliosis patient, which averages almost a full metre, while a non-affected person moves only 20-25 centimeters. These are all made possible for the first time thanks to the Vicon equipment and the TBI lab, and Dr. Haddas also recently developed a new method to quantify dynamic balance testing in spine disorder patients.
After testing is complete, all data is processed using an auto-labeling technique. Reports are then generated for physicians.
“While there is almost unlimited data from Vicon, it needs to be distilled. We generally provide five to ten highlights for the doctors.” As Dr. Haddas explains, the data summarizes walking speed, step length and width, and range of motion. “We know pain inhibits motion. Before treatment or surgery, patients tend to take shorter steps, and they adopt a wider stance to accommodate loss of balance.”
Reports generated by the lab help with patients’ diagnoses and establishing controls, pre and post-surgery, for both the short and long term. For surgical patients, one-year reports can be compared not only to pre-surgery reports, but also to healthy control subjects. Part of Dr. Haddas’ goal is to educate the medical community – physicians, physical therapists and the medical insurance industry – about how mocap-aided human motion studies can be used to better diagnose, treat, rehabilitate and track spine conditions.
But the ultimate objective, says Dr. Haddas, “Is for every patient to be completely healthy and equal to someone who requires no surgery at all.”
A lofty goal, but one that everyone involved is extremely proud to be a part of.