Modeling the Human Machine
When Professor Laurel Kuxhaus was an undergraduate at Michigan State University, she majored in both engineering mechanics and music. A wind symphony may seem an unlikely place to find engineering inspiration, but that’s exactly how Kuxhaus found her research niche. A favorite engineering professor had sparked Kuxhaus’ interest in biomechanics — the application of mechanical engineering principles to bone, muscle and tendons — and her music-major friends helped turned that budding interest into an intellectual calling.
“I noticed that there was a pretty high rate of upper-extremity injuries among my band and orchestra colleagues,” says Kuxhaus, an accomplished oboist who largely avoided the chronic wrist, elbow and shoulder pains that plagued her violinist and flautist friends. “Then I started thinking about those injuries as a biomechanical problem.” Kuxhaus started her investigation with a senior thesis on a method of mathematically modeling the wrist, then went on to earn an MS from Cornell University and a PhD from the University of Pittsburgh, where she studied the inner workings of thumbs and elbows, respectively.
While getting her PhD, Kuxhaus worked in the Orthopaedic Biomechanics Research Lab at Pittsburgh’s Allegheny General Hospital. Although the lab sounds like a factory for next-generation prosthetics, Kuxhaus didn’t spend all of her time building a better artificial arm. Instead, she and her lab associates served as a research team for Allegheny General’s world-class orthopaedic surgeons.
“Surgeons receive training in medicine, not in engineering,” says Kuxhaus. “It’s an apprenticeship system.”
But what if two surgeons apprenticed under two very different surgical techniques and want to decide which one is more effective? They could experiment on dozens of patients, but that would still yield vastly subjective results. Or they could ask Kuxhaus and her colleagues to employ the quantitative tools of engineering to measure the outcomes of each method and declare a winner.
When Kuxhaus joined the faculty of Clarkson’s Department of Mechanical & Aeronautical Engineering in July 2009, she brought with her a decade of experience in developing innovative engineering solutions to clinical problems. Like other new Clarkson professors, she was almost overwhelmed by the warm reception she received from Clarkson’s tight-knit scholarly community.
“I’ve probably accepted more invitations for research collaboration then I should have,” jokes Kuxhaus, who is teaming up on an “elbow stiffness” project with Professor Charles Robinson, founding director of Clarkson’s Center for Rehabilitation Engineering, Science & Technology (CREST). Robinson contributed his expertise in electrical engineering to develop a device for accurately measuring elbow stiffness. Together, he and Kuxhaus hope to provide a powerful new tool for physical therapists.
“If we can measure joint stiffness during recovery, then we can pinpoint the specific exercises that loosen up the right muscles and tendons to improve the patient’s quality of life,” says Kuxhaus.
Another of Kuxhaus’ research projects targets one of the most influential surgeries in professional sports: the medial ulnar collateral ligament (mUCL) replacement, also known as “the Tommy John surgery.” Until the mid-1970s, a baseball pitcher would be forced into early retirement if he tore his mUCL, an elbow ligament composed of two thick bands, one of which is always in tension. But in 1974, a pitcher named Tommy John underwent an experimental procedure in which his damaged ligament was replaced with a tendon from his right forearm. John went on to pitch for another 13 years, ending with a record-breaking 26-year major-league career.
More than 150 professional baseball players have now undergone the Tommy John surgery. The problem with the procedure is that every surgeon performs it differently. They can use replacement ligaments from arm, hamstring, knee or foot. They can connect it using a different number of holes in different locations on the elbow joint.
“All of these things are up for debate,” says Kuxhaus, who is seeking a way to mathematically describe the mUCL so Clarkson researchers can quantify its behavior as a material. “And then we’ll look at these different grafts that surgeons use as replacements and evaluate which one is mechanically the most similar.”
Kuxhaus employs a team of undergraduate students from a variety of disciplines in her research lab every semester. The latest crop includes a mechanical engineer in the Honors Program, two chemical engineers, a biomolecular science major, and a biology major.
“I usually have them working very closely with a graduate student to contribute to their projects,” says Kuxhaus. “But we also have them do what’s called intellectual research: searching literature and gathering information to answer specific questions that come up in the lab.”
As busy as she is with a full teaching schedule and research projects, Kuxhaus still finds time for the oboe.
“That was a big selling point on the community of Potsdam,” says Kuxhaus, who plays with several regional orchestras and wind ensembles. “There’s a great classical-music culture here because we have the Crane School of Music right down the road.” As for her elbow … so far, so good.
Where are you from?
Does Potsdam weather remind you of home?
A little bit!
Favorite cold weather activity?
Walking in the snow, especially at night.
Favorite piece of classical music to jump-start your brain?
“Roaring Fork” for wind quintet by Eric Ewazen.