Discovery of new muscle attachment by Tulane students sparks passion for careers in medicine

Tulane students have discovered what appears to be a new muscle attachment in some humans, a finding that was fueled by their intellectual curiosity and the guidance and mentorship of their professor.

The discovery - and its potential implications for surgeons and scholars - was outlined in the journal Clinical Anatomy.

The newly identified body part is a small muscular head found deep in the pelvis, near the front of the hip, where it connects with the larger psoas muscle that helps move the hip and stabilize the body. The new muscle attachment, dubbed the iliac attachment of the psoas major, may help steady the psoas muscle and could be important for surgeons operating in and around the hip.

"To our knowledge, this is the first report of an iliac attachment of the psoas major in humans," said R. Shane Tubbs, professor of neurosurgery and surgical anatomy director at the Tulane School of Medicine.

The path to this new discovery began in the School of Medicine's anatomy lab. Then-undergraduate students Cooper Bruce and Dominic Roy were examining cadaver sides when they spotted an unusual muscle that did not match the anatomical descriptions they had studied.

Roy called Tubbs over and asked for his insight.

"I said, 'Dominic, I have no idea what that is, but it deserves further attention,'" Tubbs said. "Like many scientific discoveries, we weren't looking for what we found."

That stroke of serendipity was guided by curiosity and underscores the idea of anatomy being a dynamic field of study, rather than settled science.

"Most people think anatomy is pretty static and doesn't change, but we contribute to it, change our understanding and broaden it," said Tubbs, who was recently named the first American co-editor-in-chief of "Gray's Anatomy." The landmark medical textbook is regularly updated to include new discoveries.

The lab discovery touched off a larger investigation, partly to see how often the muscle attachment is observed in humans. The attachment is known as an anatomical variation. Some humans have it, and others don't, Tubbs said.

The students began studying 200 additional donated specimens and found the muscle was present in 28% of the sides. They also pored over anatomy literature throughout history, some in other languages such as French and German.

The results of this research could help people with diseases, injuries or tendon irritation in their hip region. Among these is a condition known as snapping hip syndrome, which refers to a snapping sensation some people experience when they walk.

"Knowing there's an extra attachment might tell the surgeon that there's another attachment that needs to be dealt with," Tubbs said. "Hopefully this study will help people."

Roy's interest in anatomy began during his childhood, when he recalled lugging a huge book on the subject to middle school.

Tubbs' lab gave him his first experience with the research aspect of the field, he said. After finding the previously unidentified muscle, Roy, who hails from Madisonville, Louisiana, immediately applied to Tulane's Master of Science in Anatomy program and felt affirmed in his plan to pursue medicine.

"This experience really cemented that pursuit," Roy said.

The discovery also convinced him of the importance of dissecting real cadavers rather than models, which have seen increasing use nationally. Studying real cadavers allowed the students to discover the variation that was present in some people, which would not have been possible otherwise, he said.

For Bruce, who is from the Philadelphia area, the discovery and the research that followed made for a very personalized experience in the anatomy lab, he said.

"It gave a new purpose to what we were doing there," said Bruce, who is now pursuing a master's in neuroscience at Tulane. "This was the first big research project I was involved in. It felt really cool to experience."