Male-centered sports products are more than merely an annoyance for female athletes. In many cases, they contribute to an increased risk of injury for women - sometimes even ending careers.
Thanks to a combination of physiology and biomechanics, female soccer players have a two to three times higher risk of ACL tears than male players. And the standard cleats on the market, designed for and tested on men, can exacerbate the risk of injury, research has found.
For the past seven years, researchers in human physiology professor Mike Hahn's lab at the University of Oregon have been investigating the biomechanics of female soccer players, hoping to solve that problem.
"We're very excited to work so closely with a globally recognized soccer brand like Puma. It is rare to have such a productive collaboration between university researchers and an innovation team in industry."
Mike Hahn
UO professor of human physiology
Now, in partnership with sports company Puma, Hahn and his colleagues have developed a research-backed soccer shoe prototype designed to reduce ACL injury risk in women. A shoe inspired by this prototype is expected to launch soon.
"We're very excited to work so closely with a globally recognized soccer brand like Puma. It is rare to have such a productive collaboration between university researchers and an innovation team in industry," Hahn said.
Lab to cleat
The ACL is a ligament that runs diagonally across the knee, connecting the femur to the tibia. It's put under a lot of stress during soccer, especially when players make many sudden changes in direction as they respond to ball play.
ACL tears are a leading cause of soccer players missing games. Women's biomechanics place different strain on muscles, tendons and ligaments compared to men's, studies suggest, contributing to their increased risk of injury.
Shoes designed for and tested on men can further amplify that risk, in part because of the amount of traction they provide, Hahn said. While traction sounds desirable - after all, it's the whole point of wearing cleats to play soccer - too much of it can backfire. If your foot remains in place but the momentum of your body keeps going, it puts excess strain on joints and ligaments.
The Puma project grew out of a series of experiments carried out in the UO's Bowerman Sports Science Center, where Hahn's lab is located. When his team began that work, there was a lot of anecdotal evidence about the problem, but very little hard data. Over several years, the research team identified a variety of factors - like stud shape, length and positioning - that could make cleats better suited to female athletes.
In 2023, after hearing about the lab's findings at the Footwear Biomechanics Symposium in Osaka, Japan, Puma reached out with an offer to fund research that would take the work to the next level.
Since that partnership began, researchers in the Hahn Lab have been working with Puma to put their research-backed design suggestions into actual prototype shoes.
Puma and the Hahn lab co-designed and then tested two prototype cleats that had designs different from male-specific shoe designs on the market: a "mild" version, which had more subtle changes, and a "wild" prototype which had more substantial changes.
Preferred mechanics were found at a level somewhere in between the two prototypes, their tests revealed. Puma used that information to create a third version, which researchers will test this fall on the soccer field.
Prototype to Product
All testing done so far has been in the lab in a controlled setting. Researchers used force plates, motion-capture cameras and plantar pressure insoles that serve as the scientific standard to gather very controlled, precise data. But laboratory testing does not always translate to the uncontrolled nature of what these athletes will do on the pitch.
Once the team receives the new cleat design from Puma, they'll validate that shoe against a control shoe that's commercially available, Hahn said. And instead of testing in the controlled research facility, they'll run tests on the UO turf fields to see how the shoe performs in a more real-world setting.
Designs will be finalized after on-field testing finishes, with the final product expected to hit the market soon.
"The real value of this work has been in the relationships formed between the research and development teams, Hahn said. "Now that we have established that we work well together and can quickly iterate on development and testing, it's exciting to think about the impact we can have as we continue to partner on future projects."
The Wu Tsai Human Performance Alliance is a first-of-its-kind scientific collaboration aimed at optimizing human performance and catalyzing innovations in human health for all. The UO is a founding partner in the $220 million global effort, which includes five other institutions. Based out of the Phil and Penny Knight Campus for Accelerating Scientific Impact and the Bowerman Sports Science Center, the Alliance at Oregon enables collaborations across the university, including among researchers studying bioengineering, human physiology, biology, sports product design and athletics. The alliance funds research focused on understanding how to prevent injuries, including the development of innovative sports technology, and how to help people recover from injuries faster when they do occur.
