An Exploratory Study of Loading and Morphometric Factors Associated with Specific Failure Modes in Fatigue Testing of Lumbar Motion Segments

Details

• Personal Author:
  Burr D ; Gallagher S ; Litsky AS ; Marras WS
• Description:
  There is currently little information regarding factors associated with specific modes of motion segment failure using a fatigue failure model. Thirty-six human lumbar motion segments were fatigue tested using spinal compressive and shear loads that simulated lifting a 9-kg weight in three torso flexion angles (0, 22.5, and 45 deg). Twenty-five segments failed via fatigue prior to the 10,000 cycle maximum. These specimens were visually inspected and dissected so that the mode(s) of failure could be determined. Failure modes included endplate fractures (classified into nine varieties), vertebral body fractures, and/or zygapophysial joint disruption. Logistic regression analyses were performed to determine whether certain morphometric variables, amount of motion segment flexion, disk degeneration scores, and/or loading characteristics were associated with the occurrence of specific failure modes. Results indicated that stellate endplate fractures were associated with increased posterior shear forces (P<0.05) and less degenerated discs (P<0.01). Fractures running laterally across the endplate were associated with motion segments having larger volumes (P<0.01). Endplate depression was more common in smaller specimens (P<0.01), as well as those experiencing increased posterior shear force (P<0.05). Zygapophysial joint damage was more likely to occur in a neutral posture (P<0.01). These results suggest that prediction of failure modes (e.g., specific endplate fracture patterns) may be possible (at least for older specimens) given knowledge of the spinal loads along with certain characteristics of the lumbar spine. [Description provided by NIOSH]
• Subjects:
  Age Factors Aging Biomechanical Phenomena Ergonomics Hazardous Substances Musculoskeletal Diseases Musculoskeletal System Occupational Health Safety
• Keywords:
  Age-factors Age-groups Back-injuries Biomechanics Fatigue-failure Health-hazards Injuries Injury-prevention Low-back-disorders Occupational-health Posture Torso-flexion

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• Series:
  Mining Publications
• ISSN:
  0268-0033
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  Florida ; Ohio ; OSHA Region 3 ; OSHA Region 4 ; OSHA Region 5 ; Pennsylvania
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  PRL - Pittsburgh Research Laboratory
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  228-234
• Volume:
  21
• Issue:
  3
• NIOSHTIC Number:
  nn:20029379
• Citation:
  Clin Biomech 2006 Mar; 21(3):228-234
• Contact Point Address:
  NIOSH Pittsburgh Research Laboratory, P.O. Box 18070, Pittsburgh, PA 15236
• Email:
  SGallagher@cdc.gov
• Federal Fiscal Year:
  2006
• NORA Priority Area:
  Disease and Injury: Musculoskeletal Disorders of the Upper Extremities
• Peer Reviewed:
  True
• Source Full Name:
  Clinical Biomechanics
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:b979bb1862d0624d15eca8df3a4768f403029a87cec6cf4fb298a1008430eb4f48eb52c061af891f7ffbb5f68ac33cfd57442f7194e34bd14ee75562aaf7338d
• Download URL:
  https://stacks.cdc.gov/view/cdc/221150/cdc_221150_DS1.pdf
• File Type:
  [PDF - 145.70 KB ]