The Effects of a Sloped Ground Surface on Trunk Kinematics and L5/S1 Moment During Lifting

Details

• Personal Author:
  Mirka G ; Shin G
• Description:
  There are many work environments that require workers to perform manual materials handling tasks on ground surfaces that are not perfectly flat (e.g. in agriculture, construction, and maritime workplaces). These sloped ground surfaces may have an impact on the lifting strategy/technique employed by the lifter, which may, in turn, alter the biomechanical loading of the spine. Describing the changes in kinematics and kinetics of the torso is the first step in assessing the impact of these changes and is the focus of the current research. Subjects' whole-body motions were recorded as they lifted a 10 kg box while standing on two inclined surfaces (facing an upward slope: 10 degrees and 20 degrees), two declined surfaces (facing a downward slope: -10 degrees and -20 degrees), and a flat surface (0 degrees) using three lifting techniques (leg lift, back lift and freestyle lift). These data were then used in a two-dimensional, five-segment dynamic biomechanical model (top-down) to evaluate the effect of these slopes on the net moment about the L5/S1 joint. The results of this study showed an interesting interaction effect wherein the net L5/S1 moment was relatively insensitive to changes in slope angle under the back lift condition, but showed a significant effect during the leg lift and freestyle lifting conditions. The results show that under the freestyle lifting condition the peak L5/S1 moment was significantly higher for the inclined surfaces as compared to the flat surfaces (6.8% greater) or declined surfaces (10.0% greater). Subsequent component analysis revealed that both trunk flexion angle and angular trunk acceleration were driving this response. Collectively, the results of this study indicate that ground slope angle does influence the lifting kinematics and kinetics and therefore needs to be considered when evaluating risk of low back injury in these working conditions. [Description provided by NIOSH]
• Subjects:
  Biomechanical Phenomena Environmental Exposure Environmental Health Environmental Monitoring Environmental Pollution Epidemiology Musculoskeletal Diseases Nervous System Occupational Health Safety Safety Management Stress, Psychological Workload Workplace

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• Keywords:
  Author Keywords: Lifting Technique Back-injuries Biomechanical-engineering Biomechanical-modeling Biomechanical Model Biomechanics Biomedical-engineering Environmental-control Environmental-factors Environmental-hazards Environmental-stress Ground-stability Kinetic-energy Kinetics L5/S1 Joint Moment Manual-controls Manual-lifting Manual-materials-handling Safety-belts Safety-climate Safety-education Safety-equipment Safety-monitoring Safety-personnel Safety-practices Safety-programs Slope Spinal-cord Spinal-cord-disorders Spinal-shock Spinning-machines Work-analysis Work-capability Work-capacity Work-environment Work-practices Worker-health Workers

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• ISSN:
  0014-0139
• Document Type:
  Text
• Funding:
  Cooperative Agreement
• Genre:
  Journal Article
• Place as Subject:
  North Carolina ; OSHA Region 4
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  47
• Issue:
  6
• NIOSHTIC Number:
  nn:20037222
• Citation:
  Ergonomics 2004 May; 47(6):646-659
• Contact Point Address:
  The Ergonomics Laboratory, Department of Industrial Engineering, North Carolina State University, Raleigh 27695-7906
• Email:
  gsshin@unity.ncsu.edu
• Federal Fiscal Year:
  2004
• Performing Organization:
  East Carolina University
• Peer Reviewed:
  True
• Start Date:
  20010930
• Source Full Name:
  Ergonomics
• End Date:
  20080929
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:bc59dae7d200f440424ce115d5be12f6b75e59c7375d0b521bcf4c54b4294d301ea383260fcb52ffe800c673ee016c1fc0c427425b1909a5831a2cac6d1258bc
• Download URL:
  https://stacks.cdc.gov/view/cdc/188351/cdc_188351_DS1.pdf
• File Type:
  [PDF - 354.49 KB ]