Researchers are developing a dynamic brace that would modulate the forces applied to the spine but allow wearers the flexibility for daily activities for children who have scoliosis, according to a news release.
Scoliosis, a sideways curvature of the spine, affects some 6 million people in the U.S., according to past research. These include about 2% to 3% of adolescents who are diagnosed each year with idiopathic scoliosis, which is usually identified during puberty and progresses until skeletal maturity. About 1 in 500 children requires treatment using spine braces, and 1 in 5,000 needs spinal surgery, according to the release. The typical spine brace is made of rigid plastic that fits around the child’s trunk and hips and applies counter-pressure on the spine’s abnormal curve.
The rigid braces have several shortcomings: They hold the child’s upper body still and limit movement so much that users often avoid wearing the brace. As the child grows, the required external forces to correct the abnormal posture change along the length of the curve and over the course of treatment, according to the release. Having the flexibility to move when wearing a spinal brace while still applying corrective forces would be a very useful feature for patients and physicians.
Sunil Agrawal, PhD, professor of mechanical engineering and rehabilitation and regenerative medicine at Columbia University Fu Foundation School of Engineering and Applied Science in New York City, is developing a dynamic spine brace with collaborators David P. Roye Jr., MD, St. Giles Foundation Professor of Pediatric Orthopedic Surgery at the Columbia University Medical Center, and Charles Kim, PhD, professor of mechanical engineering at Bucknell University in Lewisburg, Pa. The team recently received a $1 million grant from the National Science Foundation’s National Robotics Initiative for their work.
“Every year, 30,000 children use a rigid brace to treat scoliosis, while 38,000 patients undergo spinal fusion surgery, so this award will make a big difference,” Agrawal said in the release. “If we can design a flexible brace that modulates the corrective forces on the spine in desired directions while still allowing the users to perform typical everyday activities, we will bring revolutionary change to the field.”
The team already has developed prototype wearable spine braces made of rings that fit on the human torso. These rings are dynamically actuated by servomotors placed on adjacent rings to control the force or position applied on the human body. Onboard sensors record the force and motion data and transmit the information to a host computer for monitoring and adjusting the treatment. The team also has developed a second brace that is fully passive, made of compliant components able to adjust stiffness in specific directions. However, both these braces have drawbacks, according to the researchers. The dynamic brace needs an active power source, while the passive brace cannot provide active controls.
“While we are the first group to propose parallel-actuated spine braces and compliant braces, these are just in initial phases,” Agrawal said in the release. “What we will do, thanks to the NSF award, is to design hybrid semi-active spine braces that combine the merits of the two. These will be less power-hungry and can be worn over a longer duration of time.”
The team plans to test all three types of braces on children with scoliosis at CUMC. Preliminary experiments are underway to determine the feasibility of the dynamic braces on healthy subjects with normal spines to characterize the body’s stiffness in different directions during activities of daily living.
“Scoliosis impacts the quality of life of those affected, limiting their activity, causing pain, and diminishing their self-esteem,” Agrawal said in the release. “We expect our work will transform treatment due to the ability of the brace to modulate force or position at specific locations of the spine and will greatly improve the quality of life for children with this debilitating condition.”