Inclined Surfaces – Impact on Postural Stability and Spine Loading

Details

• Personal Author:
  Agbonifo N ; Davis K ; Kotowski, Susan
• Description:
  Many work environments require workers to perform manual materials handling (MMH) tasks on surfaces that are not perfectly flat - sloped, slippery, or uneven surfaces in industries such as construction, agriculture, and maritime workplaces. Although these situations are common, there is little research focus on how working on these types of surfaces may impact the lifting strategies and techniques utilized by the worker and how this in turn affect the biomechanical loading of the spine as well as ability to maintain upright posture. According to the Bureau of Labor Statistics (BLS), falls in the workplace are a major cause of injuries and fatalities and 76% of fatalities in the roofing industry are attributed to falls. The cost of these falls in workers compensation is currently put at an average of $106,000 per fall. While falls from elevated and inclined surfaces account for many fatalities, performing MMH activities on these surfaces has the potential to impact many more workers by altering the loading of the spine and potentially increasing low back injuries. Biomechanically, these inclined surfaces require the body to maintain a stable posture by keeping the center of pressure (COP) within the base of support (BOS) when lifting. Theoretically, postural stability would have a direct impact on the biomechanics of the human system where more unstable inclinations would result in great muscle coactivation and spine loads during the handling of materials. However, little is known about the impact of inclined surfaces on spine loading. Furthermore, there is limited understanding of the potential mechanism between postural stability at the base of support and the corresponding impact on the low back system, which may be loaded at elevated levels, ultimately increasing the risk for low back injuries. This study will examine three novel hypotheses: 1) surface inclines will increase muscle coactivation and corresponding spine loading, 2) surface inclines will increase postural instability as determined by the COP moving closer to the BOS boundary, and 3) a strong relationship exists between postural stability and spine loads. These hypotheses will be tested by repeated measures within subject experimental design. The specific aims will be to: 1) determine the impact of different work surfaces (flat versus inclined at 14 degrees and 26 degrees respectively) on spine loading during routine roofing activities involving manual materials handling, 2) measure deviations of the body's COP from the BOS associated with changes in the different work surfaces, and 3) compute the relationship between postural stability indices and spine loading variables from the different work surfaces. These aims will allow for independent evaluation of the three dimensional spine loads from peak normalized electromyography (EMG) activity of the 10 major trunk muscles and 8 major postural stability muscles, three dimensional trunk kinematics and kinetics, and the path lengths (PL) and sway area or elliptical area (EA) while working on these inclined surfaces. It is expected that the study outcomes will provide beneficial information on the link between postural stability and dynamic spinal loading, which will positively impact the reduction of low back musculoskeletal disorders and potential fall related incidents resulting from inclined working surfaces. This will also potentially result in significant reduction in overall workers compensation costs across affected industries including the current healthcare costs of over $90 billion spent annually on low back injuries/disorders in the United States. This study aligns with the National Occupational Research Agenda (NORA)'s mission of stimulating innovative research and improving workplace practices including musculoskeletal disorders and construction. [Description provided by NIOSH]
• Subjects:
  Biomechanical Phenomena Ergonomics Manufacturing And Industrial Facilities Musculoskeletal System Occupational Health Safety
• Keywords:
  Biomechanics Kinesiology Materials Handling Musculoskeletal System Posture Walking Surfaces
• Publisher:
  University of Cincinnati
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Abstract or Summary
• Place as Subject:
  Ohio ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1
• NIOSHTIC Number:
  nn:20052448
• Citation:
  17th Annual Pilot Research Project Symposium, University of Cincinnati Education and Research Center, October 13-14, 2016, Cincinnati, Ohio. Cincinnati, OH: University of Cincinnati, 2016 Oct; :1
• Email:
  agbonina@mail.uc.edu
• Federal Fiscal Year:
  2017
• Performing Organization:
  University of Cincinnati
• Peer Reviewed:
  True
• Start Date:
  20050701
• Source Full Name:
  17th Annual Pilot Research Project Symposium, University of Cincinnati Education and Research Center, October 13-14, 2016, Cincinnati, Ohio
• End Date:
  20260630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:4625d77e96cb00239d30c90be55d3865edcbbf2fd293d63bd979c9ae6799c215c2088a57b9f07ba2ec5093ef94d8093fc04b5c42641190d2ca90c37c6fe12d83
• Download URL:
  https://stacks.cdc.gov/view/cdc/211974/cdc_211974_DS1.pdf
• File Type:
  [PDF - 158.20 KB ]