Posted on Jul 15
Minimus HI-REZ: Where Science Meets Design
Tucked away in the historic Ayer Mill building in Lawrence, MA is New Balance's clandestine, state-of-the-art research facility. New Balance's Sport Research Lab routinely tests a wide variety of athletic shoes to ensure they meet the company's rigorous standards in performance, durability, comfort and technical innovation. Sometimes that very innovation requires a whole new approach to testing a shoe's technical features. This was true of New Balance's forthcoming HI-REZ running shoe. Sports Research Engineer Pedro Rodrigues was kind enough to walk us through the testing they did that ultimately helped inform the shoe's unique design.
Pedro Rodrigues, Sports Research Engineer
Ambitious in both concept and execution, New Balance's Minimus HI-REZ is a running shoe designed to help maximize underfoot sensation. From early development to final product testing, the goal was always to determine how much more sensation people could feel underfoot in HI-REZ versus other minimal running shoes, a measure that's not easily quantifiable.
The other big challenge stemmed from the shoe's extreme flexibility and minimal design, which prevented the research team from using traditional testing methodologies. This forced them to get creative, developing two unique tests specific to HI-REZ. Borrowing an idea from the medical field, they conducted what's called a Filament Test: using a thin, stiff filament, they applied different amounts of force to specific areas underfoot to determine sensitivity at certain thresholds. The second assessment, called the Perception Test simply involved asking people to wear the shoes on rocks and rate the amount of texture they could feel. The results from both clearly showed people felt significantly more sensation in the HI-REZ than either the Minimus Zero or the 1080v2, (see sidebar).
The Filament Test
The Perception Test
With these tests, Pedro's team never lost sight of trying to measure how people would actually use the shoe. For instance, pavement runners routinely come into contact with different road surfaces – loose rock, breaks in cement, and the like. So the research team ensured their tests included "lower-tech" assessments such as having runners stand and walk on these different surfaces (like the loose rocks shown above) to evaluate how runners responded to the improved underfoot ground feel HI-REZ offers.
Which isn't to say the Research Lab left all their cutting-edge equipment on the sidelines for HI-REZ. Using motion capture cameras and infrared markers, they were able to build 3D reconstructions of people running — and analyze their form to determine things like "attack angles" — the angle at which your foot impacts the ground — while wearing various shoes.
The more testing the team did, the clearer it became that people were either — consciously or unconsciously — changing their running patterns in this shoe: heel strikers started to naturally transition to midfoot or even forefoot strikes. "We realized the amount of information that could get to the bottom of your foot might influence how your body would naturally transition to a different pattern of movement," says Pedro.
"Like if you're on a rocky beach, you automatically go to a midfoot strike where you'd normally walk with a heel strike."
Perhaps the most telling part of the entire testing process was the consistent reaction from users: the overwhelming level of surprise at the high amount of sensation they could feel while running. What separates HI-REZ from other running shoes is the marriage of the right materials and the idea of amplified sensory feedback. There's enough cushioning to be comfortable but not too much so as to dampen ground feel. "It's an awesome combo," says Pedro. "I definitely think the coolest thing is the sensation you get with the ground and how it brings out your innate reactions to feeling something on the bottom of your foot."