Celebration of Biomechanics Involves Chewing, Crushing

Sponsored by the Functional Anatomy and Vertebrate Evolution (FAVE) lab in the Department of Pathology and Anatomical Sciences, National Biomechanics Day was part of an international celebration of biomechanics promoted in the U.S. by the American Society of Biomechanics.

“Biomechanics is the physics of biology, or more simply, how biological beings work,” says Jack Tseng, PhD, assistant professor of pathology and anatomical sciences, who directs the FAVE lab and advises students in the Computational Cell Biology, Anatomy and Pathology graduate program.

“What most people don’t realize is that almost every aspect of their everyday life involves biomechanics,” he says. “We walk, run and jump without thinking about it. A student in class, who is bored, breaks a pencil. How are those forces generated? These are all examples of biomechanics in action.”

Even sedentary office workers can benefit from learning about biomechanics, Tseng says.

“If you understand actions and reactions, you can relate them to posture,” he says. “When we are sitting, most of our body weight is getting passed down through the vertebral column down to our pelvic area and it stops there, rather than all the way to our feet when we are standing.”

“So if you have a posture that does not channel forces correctly, you are going to have back pain,” Tseng adds. “One should think about how their body works, the forces going through bones and muscle.”

The event was open to the public and played host to groups of Buffalo-area school students. It featured several different interactive stations, including 3D-printed models of skulls and jawbones, as well as other visual displays.

“This is a way for kids to get into physics, math and biology — all in the same package,” Tseng explains. “We are introducing this flavor of science as a way to learn about science in general.”

Juan Liu, PhD, assistant professor of pathology and anatomical sciences, presented a display on the biomechanics of the ear and research involving the use of zebrafish.

“In humans, there is a lot that you normally cannot see in the hearing system, but in the zebrafish model, we can easily see the anatomical changes,” she says. “Using a computational model of zebrafish, simulations can show how vibrations move through and how the anatomical differences affect function.”

Because zebrafish are easy to maintain in a laboratory, live zebrafish are used so their hearing capacity may be measured.

“We use zebrafish for experiments and computational simulations to test hypotheses on hearing loss,” Liu says.

Another station featured graduate students who are working with different aspects of carnivorous skulls.

“One of our student’s projects is working with skull shape analysis and function — biomechanical simulation of the skull — trying to tie together some form and function relationships,” Tseng says.

While “form fits function” is a generally accepted principle, Tseng says the actual picture is a bit more complicated.

“Sometimes there is one form with multiple functions and sometimes there are multiple forms performing the same function in different species,” he says. “We are working to tease out that complex relationship.”

Tseng points out that another area of biomechanics research involves the use of motion capture technology.

“In motion capture, it’s not so much how the bones work, but how the bones and muscle work together to generate motions we are used to seeing,” he says. “Our lab focuses on chewing.”

Connor J. Grabowski, a student in the master’s program in anatomical sciences, is working on a project in collaboration with UB’s School of Dental Medicine that involves motion capture of the temporomandibular joints that attach the jaw to the skull.

The research uses motion sensors to study how normal people chew without pain and uses that to establish a baseline to understand why someone develops pain when they chew and how that modifies the way that they chew.

Perhaps the event’s most visual display and the biggest hit with the student visitors was a guillotine-like machine that vividly demonstrates the crushing capacity of the jaws of various mammals.

“In the lab, we are dissecting the bones of different species, and we are testing the mechanical strength of each bone in the skeleton across multiple species as a way to further understand form and function relationships, based on variation and bone properties,” Tseng says.

The mechanical properties are directly related to what the animal has to do.

For instance, Tseng says a cheetah would have different bone structure than a sloth because it has to run very fast as opposed to hanging and moving slowly in trees.

“We are trying to see how that locomotion preference is related to bone structure,” he notes.

Tseng says certain assumptions about biomechanics can be applied to humans.

“We know for a fact that Olympic athletes — for example, runners versus swimmers versus gymnasts — all have different distributions in bone density depending on how they train and what kind of impact sports training they undertake,” he says.

“That’s really just an extension of how we understand structure and function relationships in animals, then applied to humans,” Tseng adds.

Educating the public about biomechanics research has an added benefit for the presenters as well.

“It’s good practice for the graduate students,” Tseng says. “They get hands-on experience in talking to student groups and to adults outside their field.”

“It can take years to learn how to speak about their research in a way that’s interesting to different audiences.”

The event was held April 12 on the second floor of the new downtown Jacobs School building.