Shoe Tread Research Continues Run of Recognition with Nike Award

Hemler_Profile

When purchasing slip-resistant shoes, customers rely on the design to help prevent slips, trips, and falls ー one of the top causes of workplace injury, costing the U.S. billions of dollars each year. But how does the average consumer determine when these safety features have faded, and it is time to replace their footwear?

University of Pittsburgh graduate student Sarah Hemler studies the natural wear of shoe tread and how it impacts performance and slip risk. Her research can guide consumers on when to retire worn shoes, and she recently received an award from Nike for her work.

“Good shoe tread designs have increased friction and drainage ability, so that if you stepped on a liquid, the fluid could be drained from under the shoe to prevent slipping,” Hemler explained. “However, as tread wears down, fluid can become trapped and pressurized under the shoe instead of draining. Replacing shoes before the worn region on the shoe becomes too large is aimed at preventing this fluid pressure build-up and therefore, preventing slips and falls.”

She performed a longitudinal study as part of her PhD dissertation in Pitt’s Department of Bioengineering. In the experiment, participants started with a gait assessment in the Swanson School of Engineering’s Human Movement and Balance Lab, led in part by Kurt Beschorner, associate professor of bioengineering and Hemler’s research advisor. 

Participants then took the study to the real-world and wore two pairs of shoes, alternating each month, to their respective workplaces. As participants switched between shoes, Hemler used the lab’s tools to assess traction performance and measure shoe wear and tear.

“Through this longitudinal study, we were able to determine the effects of different wear metrics, such as the distance walked in the shoes or the size of the shoe's worn region, on changes in friction and fluid drainage ability (traction performance),” Hemler said. “The results have implications for assessing changes in traction performance and recommending shoe replacement thresholds to prevent slipping.”