But a shared interest in the science behind movement ultimately led to a research collaboration between a former collegiate wrestler, Dr. Jim Hackney, and a former professional dancer, Sara Brummel.

“The demands of dance and the demands of sports are similar,” Hackney said. “However, many sports are a matter of what you’re doing with something else, rather than how you appear doing it. With a few exceptions, in sports the important thing is what you do with a ball. You get the ball into the basket, or get the ball over the goal line. I like dance best because it is a celebration of physicality for the sake of physicality.”

To explore how different dance surfaces affect the amount of force dancers’ joints have to absorb as they leap and land, Hackney, an associate professor of physical therapy, and Brummel, an associate professor of dance, collaborated on multiple research projects, which were supported by Harlequin Floors. The support they received allowed them to offer scholarships to dance majors who participated in dance biomechanics research.

Dynamics of dance

For their research, Hackney used a sports motion program to analyze dancers’ movements, and the Pedar insole system to measure the amount of force they absorbed as they landed on traditional surfaces compared with sprung floors.

“We looked at the lower extremity, the leg and foot, and the way it absorbs forces when jumping and landing on a hard floor, versus a floor that has a bit of give to it,” Hackney said. “As the surface displaces, the lower extremities have to give less. What this is showing is that the legs and feet of the dancers don’t have to absorb as much of the force because the floor is absorbing some of it instead.”

Though dancers are known for their seemingly effortless ability to glide through the air and pivot on the tips of their toes, Brummel and Hackney note that dancers’ bodies are working hard in each move. They must stiffen joints, adjust trajectories and absorb forces without consciously thinking about it.

“When you watch a group of dancers jumping on a sprung floor, you can see the floor moving.” — Sara Brummel

“First of all, in the takeoff, a dancer needs to produce enough energy from her supporting leg to accelerate against gravity, so that the lift-off force exceeds gravity,” Hackney said. “Then, she needs to generate sufficient stiffness in the joints of her lower body to keep from collapsing. If there were no stiffness of the joints in her lower extremity and trunk, she would collapse into a heap on the ground.”

Inspired by the mechanics behind movement

“I think we live in a society where it’s often considered that everything that is important about us is from the neck up, and this body is just something that I cover with clothes and schlep around,” Hackney said. “Physical therapy is really an exploration of not only the neck up, but also the neck down as well; considering the person as an integrated whole. I was drawn to dance because it is a celebration of the physicality of our humanity.”

That same beauty in movement also captivated Brummel as a child when she watched ballerinas on television and on stage. “When I was seven, I begged my mom to enroll me in dance classes,” Brummel, said.

Dancers often retire in their mid-30s due to complications from overuse injuries and a variety of other factors. When Brummel experienced these issues in her own career, she dedicated her life to spreading the love of dance to another generation.

“After my body began to give out, I returned to school and to teaching. I was always one of those people who was analyzing how to get better.” — Sara Brummel

The insights they gained from the project inspired them to pursue follow-up research on the same topic. Their collaborative work has been published in the Journal of Dance Medicine and Science and Medical Problems of Performing Artists.