In Vivo Dynamic Lumbar Vertebral Motion and Disc Deformation During Lifting

Details

• Personal Author:
  Aiyanger A ; Anderst W ; Tashman S ; Zhang X ; Zheng L
• Description:
  Low back disorders (LBDs) remain one of most prevalent, debilitating, and costly occupational health problems in the United States. Mechanical loading on the lumbar spine is a central factor in the causation and prevention of occupational LBDs. The existing knowledge and methodological bases for evaluating mechanical forces on the lumbo-sacral (L5-S1) intervertebral disc were largely developed from static and/or in vitro cadaveric studies, or from in vivo dynamic studies that did not determine the internal vertebral movement or disc deformation. They are limited in their applicability in assessing the low back disorder or injury risks associated with dynamic work activities such as manual load lifting. The objective of this exploratory study was to characterize the relationships between dynamic responses of the lumbar spine and lifting dynamics defined by the load and lifting kinematics (i.e., dynamic postures), and begin to develop an improved model for evaluating the low back mechanical stress associated with manual tasks. Our overarching hypothesis was that more accurate understanding of the dynamic responses of lumbar spine during load-lifting will lead to more effective prevention and control of LBDs. This R21 project has taken advantage of a recently developed technique to acquire true 3D lumbar vertebral kinematics, in vivo, during a functional load-lifting task. The technique uses a state-of-art dynamic stereo-radiography (DSX) system coupled with a volumetric model-based bone tracking procedure, offering unprecedented accuracy in lumbar kinematics measurement. Twelve asymptomatic participants (7 male, 5 female) with no self-reported history of low back pain performed weight-lifting tasks, while the DSX system imaged their lumbar motions. A model-based tracking procedure then determined the 3D lumbar kinematics, followed by kinematic and statistical analysis/modeling procedures to explore the hypothesized effects and gender differences. Results revealed motions occurring simultaneously in all the intervertebral joints as functional units of the lumbar, including substantial translations, and largely equitable contributions to overall lumbar motion from individual segments or joints. We identified significant gender differences and some effects of the magnitude of load handled on various aspects of the lumbar intervertebral motions. We also discovered that the there is substantial migration of the instantaneous centers of rotation (ICR) for the segmental motions. This study achieved a milestone technical success by demonstrating the feasibility of capturing continuous 3D in vivo lumbar intervertebral kinematics during functional tasks. The data acquired from this exploratory study, though preliminary in nature, provide updated knowledge regarding lumbar spine function and related influencing factors, and challenge some of the existing assumptions or understanding and tools and methods thus derived. The technical ability established in this study, and the kind of data and knowledge it can generate, will allow more accurate assessment of the mechanical stresses experienced by the low back and more effective recognition and intervention of the risks, thus leading to potentially a profound long-term impact on low back injury prevention and control. [Description provided by NIOSH]
• Subjects:
  Biomechanical Phenomena Musculoskeletal System Nervous System Occupational Health Safety
• Keywords:
  Biomechanics Injuries Injury Prevention Kinetics Low Back Disorders Low Back Pain Manual Lifting Spinal Cord
• Series:
  Grant Final Reports
• Publisher:
  National Institute for Occupational Safety and Health
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Final Grant Report
• Place as Subject:
  OSHA Region 3 ; Pennsylvania
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  OEP - Office of Extramural Programs
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-30
• NIOSHTIC Number:
  nn:20055095
• NTIS Accession Number:
  PB2019-100823
• Citation:
  Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, R21-OH-009960, 2014 Sep; :1-30
• Contact Point Address:
  Xudong Zhang, Ph.D., 3820 South Water Street, Orthopaedic Research Laboratories, University of Pittsburgh, PA 15203
• Federal Fiscal Year:
  2014
• Performing Organization:
  University of Pittsburgh at Pittsburgh
• Peer Reviewed:
  False
• Start Date:
  20110901
• Source Full Name:
  National Institute for Occupational Safety and Health
• End Date:
  20140831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:00c423922c1f9cace463ec46ae45c9ec1b8d9bae1821173b73403d440ae88ebb2afae3c5a50f309d5e4f6c05c71b44e16c876d50bbfd3047e8d59b5fe11d3f8d
• Download URL:
  https://stacks.cdc.gov/view/cdc/218833/cdc_218833_DS1.pdf
• File Type:
  [PDF - 890.96 KB ]