Spine Biomechanics Laboratory Quantitates Functional Outcomes After Spine Surgery

Benefits of assessing biomechanical outcomes advances research on musculoskeletal medicine and improves functional outcomes.

Research emerging from the Spine Biomechanics Laboratory at Texas Back Institute (TBI) may better elucidate the biomechanical and neuromuscular risk factors associated with spinal conditions and help define the most appropriate and effective treatment options.

evaluating a patient's gait on a tabletImage Courtesy of The Spinal Biomechanics Laboratory at Texas Back Institute © Used with Permission.Using human motion capture, dynamic electromyography sensors, and force plates technology, the lab is designed to quantify patients’ functioning before and after spinal surgery in terms of gait, balance, posture, muscle coordination, stair climbing, and sit-to-stand motion analyses. The data also is used to define muscle activation parameters: onset (when the muscle is activating), magnitude (how much the muscles are working), and volume (energy expenditure). Together, this information is used to quantify short-term (3-months) and long-term (1-year) functional improvement postsurgery in patients who participate in research studies at TBI.

aspects of a patient's functional abilities evaluated at The Spinal Biomechanics LaboratoryImage Courtesy of The Spinal Biomechanics Laboratory at Texas Back Institute © Used with Permission.

Lab Provides Quantitative Outcomes Data

The lab “offers objective, quantitative, and reliable data for spine surgeons and physical therapists to use when assessing the functional outcomes of surgery,” explained Ram Haddas, PhD, MSc, MEng, Director of Research at the TBI Research Foundation in Plano, TX.

The lab was created to overcome the potential limitations of traditional measures of spine surgery outcomes, namely imaging findings and patient questionnaires (eg, Oswestry Disability Index, SF-36). Imaging findings are reliable but conducted in static positions and findings can change with movement, Dr. Haddas noted. In addition, patient questionnaires are subjective with studies showing that patients do not always understand the survey questions or how to estimate pain level, Dr. Haddas said.

“We now have robust irrefutable data manifesting patients' ability to walk and stand better” after treatment, said Ralph Rashbaum, MD, Orthopedic Spine Surgeon at TBI. “This is something that, from a standpoint of ongoing research, becomes a necessity in musculoskeletal medicine.”

“The laboratory gives us the ability to objectively measure how our patients are doing before and after intervention,” said Isador H. Lieberman, MD, Director of the Scoliosis & Spine Tumor Center at TBI. “It is important information, and valuable for patients to see the improvement.”

Dr. Haddas was recruited to initiate and build the Spinal Biomechanics Laboratory, which is the first spine-related human movement biomechanics lab to be incorporated within a private practice spine center in the United States.

Since its inception in December 2015, the laboratory has assessed more than 100 patients and is expected to analyze between 250 and 300 patients in 2017.

The Benefits of Assessing Biomechanical Outcomes

The biomechanical analysis can help determine if patients are using muscles efficiently after surgery and if their muscles are coordinated. The findings can be used to help fine tune physical therapy programs and help motivate patients to continue exercising.

“I use gait analysis in my practice to evaluate outcomes,” in patients with various spinal conditions, including cervical myelopathy, scoliosis, sacroiliac joint dysfunction, said Scott Kutz, MD, Neurosurgeon at TBI. “Gait analysis gives objective data so we can measure stride length and cadence of gait, and using EMG activity to see how efficient gait is in terms of muscle activity postoperatively compared with preoperative.”

For example, in a patient with scoliosis, comparison of pre- and postoperative analysis can show whether patients are using both sides of their body equally when walking and if muscles in the low back, hamstrings, or glutes are firing excessively in the standing position compared with healthy controls, Dr. Haddas explained.

“Just because patients don’t sway when asked to stand for 1 minute, doesn’t mean that they aren’t using an excessive amount of energy to hold themselves upright,” Dr. Haddas said.

“In addition, while we always tell patients to strengthen their core, if muscles are not coordinated and not firing at the right time as the load is coming (lifting, walking, sit to stand activity) they may not be efficient and may expend more energy than necessary,” signaling the need for targeted physical therapy, Dr. Haddas told SpineUniverse.

Lab Advances Research on Musculoskeletal Medicine

The laboratory is actively studying patients with scoliosis, cervical and thoracic myelopathy, chronic back and neck pain, sacroiliac joint dysfunction, and total disc replacement for lumbar and cervical degeneration. Within each group, the researchers are comparing gait, balance, lifting, sit-to-stand motion, and stair climbing before and after several types of treatments.

patient's function evaluated while turning and liftingImage Courtesy of The Spinal Biomechanics Laboratory at Texas Back Institute © Used with Permission.For example, Dr. Haddas and colleagues recently presented a study on gait analysis in patients with adult degenerative disease who used walking sticks versus walkers at the 17th Annual International Society for the Advancement of Spine Surgery Conference in Boca Raton, FL. The findings suggest that substituting walking sticks for walkers promotes a more upright posture and improved sagittal alignment, as a result of their higher grips. Postoperatively, walking sticks helped patients maintain surgical correction of their kyphotic deformities, the researchers found.

Click Here to View Video of TBI’s Spine Biomechanics Laboratory

The researchers have presented data on a variety of other topics, including pre- and post-surgical gait analysis in adult degenerative scoliosis, gait analysis in adult surgical candidates with cervical spondylotic myelopathy, and the correlation of biomechanical parameters measured by gait analysis with the functional parameters measured by self-reported questionnaires in patients with adult degenerative scoliosis, among other topics. In addition, a study on altered ground reaction forces in adults with cervical spondylotic myelopathy will be presented in the best paper session at NASS 2017.

With more data, Dr. Haddas hopes that this research will better characterize the effect of specific treatments on patients’ functional outcomes to help guide preoperative planning.

Updated on: 09/19/19
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Benefits of Walking Sticks in Patients with Adult Degenerative Scoliosis

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