Tether Device Aims to Improve Swimmers’ Times, Go Beyond the Pool

Most spectators of competitive swimming know about the backstroke, breaststroke, butterfly and freestyle in events such as the summer Olympics.

But it’s not likely they know exactly what goes into a stroke or how swimmers adjust their style to make their way to the winners podium.

A University of Pittsburgh research team has developed a new device, called Impulse, which measures force production to aid coaches and athletes in determining better ways to improve performance and prevent injury. And they’re starting with students on Pitt’s Swimming and Diving team.

“There have been methods of measuring stroke parameters which have improved stroke mechanics in swimmers, but given a relationship between muscular strength and performance, there is a definite need to measure force production in water,” said Impulse researcher Elizabeth Nagle, associate professor in Pitt’s Department of Health and Physical Activity within the School of Education. “Determining force production could lead coaches to develop better methods to assess, monitor and develop training regimens for their swimmers that may contribute to faster swimming performances.”

At a demonstration at the Joe C. Trees pool in January, swim team members were tested using the Impulse system, which consists of a swim belt attached to a non-elastic tether linked to a force sensor anchored to a pole or starting block. The force sensor wirelessly transmits data in real time to a tablet or cell phone.

When the researchers were ready to record, Marc Christian, assistant coach for Pitt Swimming and Diving, gave his student team members the go-ahead signal.

The students swam as if they were in a competitive freestyle meet, racing in place while the Impulse device tracked their movements and relayed information via Bluetooth to computers nearby.

“We want to help athletes understand how they’re moving through water,” said Christian. “Analyzing strokes in swimmers is a bit of a black box because you’re relying on eyesight and not hard data.”

After a few trials of 10 and 15 seconds each, the swimmers were done with the test.

“We’re hoping to provide valuable feedback to coaches to use as an additional tool to help improve swimming performance,” said Nagle. “We can successfully record multiple swimmers simultaneously, which is great for coaches since they manage multiple athletes at once.”

Along with Nagle and Christian, the Impulse research team includes the Department of Sports Medicine and Nutrition’s Matt Darnell and Katelyn Allison, both assistant professors; Jackie Nagle Zera, former University of Pittsburgh postdoctoral researcher and current assistant professor at John Carroll University; and Carma Sprowls Repcheck, assistant professor in Pitt’s Department of Health and Physical Activity.

Nagle said her team and Christian have had discussions about performance testing since 2016, after looking at the calls for proposals relating to performance improvement from Pitt’s Athletics Department and the Innovation Institute for the inaugural Performance Innovation Tournament in 2018.

“Aquatic physiology is my research background and I thought, ‘Wow, that’s interesting what they’re looking for,’” Nagle said. “Several years ago, we had developed a test protocol to measure force in water with an individual swimmer that was deemed reliable. We then thought how we can develop this system to be easy to use by coaches. Things just fell together for us and we put our heads together to develop this further.”

The team won first prize at the competition, which included $80,000 in funding. The team was also a finalist in the 2018 Innovation Challenge and published a study about the device’s feasibility as an assessment tool in the Journal of Strength and Conditioning Research last year.

While Impulse could help increase the Pitt swim team’s medal collection, it could have a place outside of the pool too. One of the swimmers demonstrated the Impulse device tethered to a wall and performed isometric movements, specifically shoulder rotation.

“We can set this device up in a number of different ways to measure upper and lower body strength,” Darnell said. “We can compare limb-to-limb and protagonist versus antagonist muscle groups and see if there’s any discrepancies or side-to-side differences between muscle groups. We can use that to analyze athletes and identify injury risks.”

The researchers are working on ways to make Impulse more user friendly while continuing its testing throughout the term. They worked with staff members Jarad Prinkey and John A. Holmes from Pitt’s Swanson School of Engineering to take Impulse from concept to initial design and then a fully functional prototype for testing, all in about two months. Prinkey and Holmes work out of the Swanson Center for Product Innovation, which provides product development not only for faculty and students in the engineering school but units throughout the University.

The Impulse project is just one example of a new initiative at Pitt to engage the Athletics Department with Pitt researchers to develop innovations around human performance that can give Pitt athletes a competitive edge, while creating opportunities to commercialize these solutions to benefit society more broadly.

“Pitt student-athletes work every day to push the limits of endurance, skill and teamwork. Likewise, the Innovation Institute and Office of Research are working hard to push the opportunity space in bringing engineering, data science and health science experts together to advance innovation in human performance,” said Evan Facher, vice chancellor for innovation and entrepreneurship at Pitt and director of the Innovation Institute. “We’re doing this in concert with the Clinical and Translational Science Institute, the Provost’s Office and the Athletic Department, and in some cases, with Pitt startups and other industry partners.”