Two Tulane University undergraduates came across an anatomical feature in a cadaver lab that their professor could not immediately identify.
Dominic Roy and Cooper Bruce were 19-year-old sophomores when they made the discovery in 2024. Roy recalled that he and Bruce were volunteering in the lab with R. Shane Tubbs, a neurosurgery professor and director of surgical anatomy at Tulane’s medical school.
The students were examining hip specimens to compare where the iliacus connects with the psoas major, a muscle that extends from the lower back through the pelvis to the upper thigh. While searching for the iliocapsularis, a muscle on the outer side of the hip, Roy noticed another structure.
It looked similar to a muscle but sat on the opposite side of the iliac fascia, near the groin area. Roy asked Tubbs to identify it. The structure hadn’t come up in their earlier discussions, and Tubbs was unsure what it was, too.
The team searched textbooks and existing research but couldn’t find a description of the feature. That suggested it might be previously undocumented. Other physicians and medical students later joined the investigation, gathering around the specimen to examine and photograph it.
The findings have since been published in the journal Clinical Anatomy. Tubbs described the discovery as a fortunate accident: Roy and Bruce had uncovered a part of a muscle that the team had not yet examined. It lies deep in the pelvis and extends toward the front of the hip.
Researchers have not established what the muscle does. Its position offers one possible clue: it may help stabilize the psoas major, which plays a role in bending the hip. The team hopes to learn whether MRI scans can show the attachment and whether it is associated with symptoms.
More research is needed, Tubbs said, including whether the muscle can be seen on medical imaging and whether it contributes to patients’ problems. Understanding it could matter as hip procedures become more common. If the muscle is weak, physical therapy might help; if it is overly active and causing symptoms, an injection could potentially reduce its activity. Surgeons may also want to consider it during hip operations.
The feature was not present in every cadaver examined, reflecting the natural variation in human anatomy. The researchers also found a similar attachment in gorillas, raising the possibility of an evolutionary connection.
Bruce said it is difficult to explain why the structure appears in some people but not others. A person’s activities might be relevant, he suggested, but the team did not have the personal histories needed to test that idea.
Working with real cadavers gives medical students a chance to see variation that standardized synthetic models cannot fully represent, Tubbs said. Human anatomy may seem thoroughly mapped, but new observations are still possible.
Roy said that experience is valuable preparation for treating patients. The discovery has also encouraged both students, now seniors, to continue exploring medicine. Roy plans to pursue a master’s degree in anatomy.
The researchers expect the finding will need to be checked in people from different regions before it is fully understood. In time, Tubbs said, it may be included in anatomy textbooks. For now, the discovery is a reminder that anatomical research is ongoing, even when the textbooks make it seem settled.
