If the Shoe Fits
PITTSBURGH (December 10, 2015) - According to
the Centers for Disease Control and Prevention, workplace slips, trips and
falls cost the U.S. economy $180 billion each year* and represent the majority
of nonfatal injury costs. While injury prevention strategies can save lives and
reduce costs, one factor rarely taken into consideration is footwear.
Researchers at the University of Pittsburgh’s Swanson School of Engineering are
exploring new techniques to better predict the wear rate of shoes in order to
improve shoe design and replacement policies to reduce slip and fall accidents.
“Impact of Worn Shoes on Slipping,” was the recipient of a four-year,
$1,519,208 R01 grant from the National Institute of Occupational Safety and
Health. Principle investigator is Kurt E. Beschorner, Research Assistant
Professor in the Swanson School’s Department of Bioengineering. Co-Investigators are Joel
M. Haight, Associate Professor of Industrial Engineering and Director of Pitt’s
Safety Engineering Program; and Mark S. Redfern, William Kepler Whiteford
Professor of Bioengineering.
mode of transportation is walking, and every time you move your feet you risk a
slip or a trip that can lead to a fall,” Dr. Beschorner said. “What we want to
address is the preventative side to falling. We have preventative screenings
for many health issues such as cancer. Yet relatively few studies have been
done to reduce fall prevention by improving the slip resistance of shoes.”
Beschorner compared the research to advances in tire technology and tread wear.
Like the grip between a car’s tires and the road, the friction between the sole
of the shoe and a walking surface maintains a person’s grip to the floor. Shoes
that are heavily worn have a reduced coefficient of friction (COF) and are
associated with increased risk of slipping. When worn, treads can no longer
channel fluids from beneath the shoe. The fluid then becomes pressurized and
the COF decreases, thereby increasing the chance of a fall.
researchers note that knowledge gaps exist regarding the factors that
contribute to shoe wear rate and the wear thresholds at which the COF begins to
decrease. This gap inhibits design and selection of more effective
wear-resistant shoes and preventative programs that replace shoes before they
become too worn. To identify the underlying causes of shoe wear and the tread
thresholds where shoes become unsafe, new technology developed by the research
team will simulate wear using a robotic slip-tester and measure shoe tread
hydroplaning using a fluid pressure measurement system. The research will also
develop new computational models that can be used to predict shoe wear for new
shoe sole designs.
this study unique is the systematic way in which shoe tread wear will be
studied,” Dr. Beschorner said. “We’ve developed novel technology to test shoe
tread drainage to more precisely measure how shoe wear is impacting
slipperiness. We will examine shoe wear and determine specific limits to wear,
so that people know when to replace worn shoes. Then we will determine the
critical factors that impact how quickly shoes wear, which can help
manufacturers build a more durable shoe.” ### *Sum of fatal  and
non-fatal  injury costs.  Florence, C., Simon, T.,
Haegerich, T., Luo, F., & Zhou, C. (2015). Estimated lifetime medical and
work-loss costs of fatal injuries-United States, 2013.MMWR: Morbidity and
mortality weekly report, 64(38), 1074-1077.  Florence, C., Haegerich, T.,
Simon, T., Zhou, C., & Luo, F. (2015). Estimated lifetime medical and
work-loss costs of emergency department-treated nonfatal injuries-United
States, 2013. MMWR: Morbidity and mortality weekly report,64(38), 1078-1082.