A group of Viterbi students designed a spinal disc model almost exactly like its biological counterpart. (Image / Midjourney)
Studying the human body is an ever-evolving process. As we continue to advance our understanding of how the body functions, a group of students at the Alfred E. Mann Department of Biomedical Engineering at the USC Viterbi School of Engineering has developed a new model to help medical professionals.
The project began at the 2025 USC “Make-A-Thon” hosted by the Associated Students of Biomedical Engineering at USC last March. After the event, Dr. Joseph Derian, an assistant professor of clinical physical therapy at the USC Division of Biokinesiology and Physical Therapy, approached students Arjun Karnwal, Nicholas Dorgan, and Anson Li. He asked them to build out an initial prototype with the hypothesis that this spinal disc model could significantly improve understanding of the spinal anatomy and bring new innovation to the physical therapy space.
“I was inspired by how the biomedical engineering students were so innovative and excited to learn about developing new prototypes in a physical therapy-minded space,” Derian said.
The need was clear. In physical therapy classes, it’s typically much easier to analyze mobility in joints like knees and shoulders using humans as test subjects. Internal structures like spinal discs — which sit between the vertebrae, allowing the spine to flex, bend, and twist while also functioning as shock absorbers — are far harder to examine when teaching students.
To achieve this, Karnwal, Dorgan, and Li sought to design and implement a spinal disc model that was comparable to its biological counterpart. This project, “Design and Implementation of Anatomically and Physiologically Accurate Spinal Disc Teaching Models,” was designed to help medical professionals teach students about the human spine, more accurately discuss procedures, and potentially assist in patient education and understanding.
“Our basic goal was creating something that could be used to help understanding and comprehension in the classroom,” Karnwal said. “It’s really difficult to see into the spinal cord and understand how it moves. So making the unseen seen is something that we were looking for.”
Over the course of nearly a year, the students worked closely with Dr. Derian and the physical therapy faculty, experimenting with different materials and models before landing on a bilayered silicon model, with anatomical accuracy guaranteed via from custom, 3D-printed molds.
“The project was highly iterative, a fancy way of saying that the students had to try lots of different strategies before we found one that produced satisfactory results,” said Gerald Loeb, a professor of biomedical engineering and neurology at the Alfred E. Mann Department of Biomedical Engineering. “We are looking forward to adding some samples that they made to our project display area so that other students can be inspired by and learn from their results.”
The result of all these iterations was a disc with a high degree of anatomical and physiological accuracy, per literature review. Throughout the development process, valuable insights were contributed from all corners of the physical therapy department.
“We mainly showed the model to Dr. Derian. But you’d have people on his team just coming by, and he’d rope them in and say, ‘hey, check out what they made,’ and give your feedback on it,” Dorgan said. “It was very interesting to have multiple perspectives from basically everyone in the office.”
Dr. Derian was thrilled with the final product the Viterbi students delivered.
“It has been a great experience so far and I am excited to see how capable these students can be so early in their careers. I hope to continue working with them to develop more models for patient education and medical education,” Derian said.
After implementing the discs into the USC physical therapy curriculum and receiving overwhelmingly positive feedback, the team’s ambitions began to grow. Medical centers are already using the model to teach students about spinal (cord) mechanics, and it could also help physical therapists identify spinal disc injuries in the future.
Since then, the team has created three discs with different hardness representing the progression of spinal aging.
“By comparing healthy and aging discs models side by side, we hope to help therapy professionals understand the effects of spinal aging and disc degeneration,” said Li.
“The team looks to share their products with other physical therapy institutions to promote a deeper understanding of spinal cord mobility for all,” said Jaron Kawamura, current president of the Associated Students of Biomedical Engineering at USC.
As their work continues to gain attention in the physical therapy education space, the team will continue to improve their model to help illuminate the previously invisible inner mechanics of spinal cord mobility. The team hopes their tools can enable better insight and training, leading to better patient outcomes.
Published on June 8th, 2026
Last updated on June 8th, 2026