Preventing slip and fall accidents: focus on the footwear.

Details

• Personal Author:
  Beschorner K ; Haight J ; Hemler S ; Iraqi A ; Moghaddam S ; Moyer B ; Redfern M
• Description:
  Falls are a leading and growing contributor of occupational injuries. Slipping events are estimated to account for approximately half of same-level falls. Slips occur when the amount of friction force required to sustain walking exceeds the amount of force that can be generated between the shoe and walking surface. Footwear has emerged as a critical factor influencing slip and fall risk. Furthermore, footwear is subject to engineering controls in many industries. However, few methods exist for assessing footwear in a workplace setting that are based on rigorous research. In this abstract, we review recent research performed by our group to better understand footwear friction mechanisms and use this improved understanding to suggest interventions for preventing slips and falls. Our research uses novel in vitro experiments, in vivo experiments, and modeling methods (in silico) to develop an understanding of the shoe-floor friction mechanisms. This research has identified two main mechanisms that are relevant to slip and fall accidents: hydrodynamic pressures and hysteresis friction. Specifically, slip risk can be mitigated by reducing hydrodynamic pressures and maximizing hysteresis friction. Our research has developed novel experimental methods that use pressure sensors embedded in the floor along with either a robotic slip-tester or human subjects to measure hydrodynamic pressures. In addition, our group has developed multiscale finite element modeling techniques to predict hysteresis friction based on shoe and floor roughness, shoe material properties and the geometry of tread. These models simulate hysteresis friction between micrometer scale shoe and floor asperities and integrate this information with a model that predicts contact pressures across a shoe heel surface. Collectively, these studies can be used to guide footwear design and inform safe footwear guidelines for preventing slip and fall accidents in organizations and industries that establish such footwear guidelines and policies. Our research has led to findings that shoes with improper tread drainage or worn treads increase hydrodynamic pressures when contacting liquid contaminants. Shoes tend to wear unevenly and one region of tread typically becomes completely worn even as other regions are mostly intact. The worn patch is associated with an increase in hydrodynamic pressures and a reduction in friction. When hydrodynamic pressures are low, our research suggests that hysteresis friction can be increased by distributing the contact force over an increased tread area. This can be accomplished through softer shoe materials, beveling the heel of a shoe, or through the geometry of the tread. Interventions can be readily implemented in the workplace based upon these findings. First, the worn area of shoes can be easily measured with a ruler and increased risk occurs when the area is greater than a specific size (about the size of a dime). Furthermore, our research team has found two footwear measurements that are well correlated with friction in slip-resistant shoes: tread contact area and tread width. Tread contact area can be measured with an inkpad and paper, a scanner and simple image processing software. Tread width can be measured simply using a ruler. If verified as effective in field tests, these methods could reduce slip injuries in many workplaces.
• Subjects:
  Accidents, Occupational Air Pollutants, Occupational Air Pollution, Indoor Health Care Facilities Workforce And Services Manufacturing And Industrial Facilities Occupational Health Paint Preceptorship Safety Staff Development Surveys And Questionnaires Workplace

  More +
• Keywords:
  Biomechanical Modeling Footwear Injuries Slips, Trips, And Falls STF Walking Surfaces
• Publisher:
  National Institute for Occupational Safety and Health
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Abstract
• Place as Subject:
  OSHA Region 3 ; Pennsylvania ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  126-127
• NIOSHTIC Number:
  nn:20055972
• Citation:
  National Occupational Injury Research Symposium 2018, (NOIRS 2018), October 16-18, 2018, Morgantown, West Virginia. Morgantown, WV: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, 2018 Oct; :126-127
• Federal Fiscal Year:
  2019
• NORA Priority Area:
  Manufacturing ; Wholesale and Retail Trade
• Performing Organization:
  University of Pittsburgh
• Peer Reviewed:
  False
• Start Date:
  20150930
• End Date:
  20190929
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:6600cde52ebb634a6a40752ba9188e1e5a9387aece097aa1db200e0fd772ec16c2a631e0383659dde65ee7734f52bb4612dbeb7f5672e1ac156352d3a45c7b62
• Download URL:
  https://stacks.cdc.gov/view/cdc/181749/cdc_181749_DS1.pdf
• File Type:
  [PDF - 37.13 KB ]