Mapping the traction performance of work shoes during natural progressive wear.

Details

• Personal Author:
  Beschorner K ; Haight J ; Hemler S ; Redfern M
• Description:
  Background: Falls, slips, and trips continue to be a major cause of injury in the workplace. In 2016, these incidences accounted for over 26 percent of all nonfatal occupation injuries in the U.S. Furthermore, 40-50 percent of fall-related injuries can be attributed to slipping. As slipping incidences occur at the shoe-floor interface, shoe wear is a major risk factor for slip and fall accidents. Therefore, there is a need to better understand how shoe outsole design affects progressive shoe wear and therefore shoe performance. Slip-resistance is often measured by available coefficient of friction (ACOF) which is the friction that acts to prevent slipping between surfaces; a reduction in ACOF often leads to a higher chance of slipping. Higher under-shoe fluid-pressures have been linked to lower ACOF and a higher likelihood of slipping in worn shoes. Methods: In this pilot study, ACOF and fluid pressures were measured for two different shoe designs (Shoe A, Shoe B). Shoes were worn by 4 human subjects on man-made surfaces for 23 person-months and data was collected after each month of wear. Fluid pressures were numerically integrated across the shoe surface to calculate the fluid force (the load supported by the fluid during slipping). A pedometer tracked the usage of each pair of shoes. Repeated-measures ANOVA was used to determine the impact of shoe design, distance walked, and side (left versus right) on ACOF and fluid pressures. Results: The baseline ACOF values ranged from 0.17 to 0.41 and 0.13 to 0.20 and fluid forces ranged from 0 to 23.5 N and 0 to 10.1N at baseline levels for Shoe A and Shoe B, respectively. The change of ACOF from baseline values ranged from -0.058 to -0.226 for Shoe A and -0.017 to -0.049 for Shoe B. Although Shoe A exhibited the highest average baseline ACOF (39% higher than Shoe B), the two shoes had similar ACOF values after being worn. Repeated-measures ANOVA methods showed that the ACOF for both shoes was significantly affected by shoe type (p=0.0192, F(1,52)=5.84), the distance walked (p<0.0001, F(1,54)=28.16), and their interaction (p=0.0024, F(1,52)=10.16). The fluid force was affected by shoe type (p<0.001, F(1,53)=39.03), the distance walked (p<0.0001, F(1,55)=37.00), their interaction (p=0.0006, F(1,52)=13.23), as well as the interaction between side (left/ right) and the distance walked (p=0.0441, F(1,52)=4.26). Discussion: This research supports previous findings that as shoes are worn, ACOF decreases and fluid force increases. Shoes vary in their sensitivity to shoe wear. Although current wear standards suggest replacing shoes after 6 months of wear, this research suggests that for certain shoe types, the point at which shoes should be replaced may occur before the time of recommended replacement. Overall, this research confirms that the shoe outsole design and shoe wear condition affect shoe performance and that replacement guidelines may require consideration of shoe design. Therefore, it is critical for footwear manufacturers to track the influence of wear on traction performance in order to develop appropriate replacement guidance for their shoes and for users to monitor shoe condition.
• 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

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• Keywords:
  Footwear Injuries Risk Factors 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:
  129
• NIOSHTIC Number:
  nn:20055973
• 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; :129
• Federal Fiscal Year:
  2019
• NORA Priority Area:
  Manufacturing ; Wholesale and Retail Trade
• Performing Organization:
  University of Pittsburgh
• Peer Reviewed:
  True
• Start Date:
  20150930
• End Date:
  20190929
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:da3d9196a48bc5bd20ae9d61e69361414b7f44ab41d40009e7a0740297a7f792d66a02e8dd8deee27b4af0c8772722dde3b9f516288005181b001b1fe9787438
• Download URL:
  https://stacks.cdc.gov/view/cdc/181750/cdc_181750_DS1.pdf
• File Type:
  [PDF - 31.22 KB ]