See John skate
Unique simulation helps skaters fine-tune their jumps
3:51 p.m., May 12, 2011--“Feet feet feet. Bad feet,” says Olympic coach Frank Carroll to 20-year-old Andrew Gonzales as he points to an avatar of the skater on the computer screen. “This is a good triple, but you can do better. If you change your leg position and bring your elbow in, you can turn this jump into a quad.”
Thanks to a simulation developed at the University of Delaware, the two can actually see what will happen if Gonzales follows Carroll’s suggestions.
Oct. 14: SOE colloquium
With funding from U.S. Figure Skating (USFS) and the U.S. Olympic Committee (USOC), Prof. Jim Richards and simulation expert Tom Kepple have developed the innovative tool to help coaches fine-tune the jumping techniques of elite skaters.
According to Richards, 10 high-speed cameras in the ice rink ceiling record the skater, who is outfitted with a set of carefully placed anatomical markers, doing a prescribed jump. The images are fed into the computer, where software determines the location of the markers in three dimensions.
Those data are then transferred to motion analysis software, which calculates all of the mechanical parameters critical to the jump and generates a three-dimensional model. At that point, various aspects of the jump, including position as well as movement, can be manipulated to maximize jump rotation.
On April 4, Gonzales and Carroll, a former competitive skater himself and coach of 2010 Olympic gold medalist Evan Lysacek, spent the day at UD’s Gold Ice Arena, along with 17-year-old skater Mirai Nagasu; Mitch Moyer, senior director of athlete high performance at USFS; and Peter Zapalo, sports sciences and medicine manager at USFS.
“What’s different about this technology is that it lets us look at the ‘what-ifs,’” said Moyer. “We can see on the computer screen what will happen if the skater does x or y.”
Analyzing the model of Gonzales, Moyer suggested, “Try straightening the right leg a little and see what happens.”
A tweak to the model seemed to work. “Look at thatlook at the difference,” Carroll said.
Gonzales got the message. He would work to incorporate the changes into his next session. But now it was Nagasu’s turn to go through the process.
“Don’t be afraid to trust that it’s OK to spin faster,” Richards told her as she prepared to go out on the ice for a series of triple axels. Soon, data on Nagasu’s jumps appeared on the screen, and the group was back to figuring out what changes would make a difference.
So far, just one skater, Adam Rippon, has gone through the entire process of being recorded, getting feedback for improvement, and implementing the changes, but the results were striking.
“He completed his first quad after his second visit here,” Richards said. “At the end of the day, we can always do it on the computer, but it takes the coach and the skater working with us to make it happen on the ice.”
Also, while the simulation technology has so far been used exclusively for skaters, it has other potential applications. “It could be a useful tool for other sports that involve the athlete moving through the air, such as diving and gymnastics,” said doctoral student Jeff Mattson.
About the research team
Jim Richards is Distinguished Professor in UD’s Department of Kinesiology and Applied Physiology. Jeff Mattson, Kat Arbour, and Stephanie Russo are doctoral students in the Biomechanics and Movement Science (BIOMS) interdisciplinary graduate program. Arbour and Russo are also former figure skaters. Tom Kepple is a simulation expert with C-Motion and an affiliated faculty member in the BIOMS program.
C-Motion was created in 1997 to transfer the Move3D technology from the National Institutes of Health into the commercial market. Visual3D is the product that resulted from this effort, and it was released commercially in mid 2001. C-Motion has since focused on the needs of the medical research, sports research, and rehabilitation communities with leading-edge 3D motion analysis capabilities. The company is located in Germantown, Md.
Article by Diane Kukich
Video by Andrea Boyle
Photos by Evan Krape