Cyclic Load Magnitude Is a Risk Factor for a Cumulative Lower Back Disorder

Details

• Personal Author:
  Le P ; Lu Y ; Patel V ; Solomonow M ; Zhou BH
• Description:
  OBJECTIVE: Epidemiological data suggest that high loads lifted by workers engaged in static and cyclic daily activities may be a risk factor for low back disorder. Our previous research provided physiological and biomechanical validation of the epidemiological data for static load conditions. The objective of this report was to provide physiological and biomechanical experimental validation to the epidemiological data in cyclic (repetitive) load conditions. METHODS: Three groups of in vivo feline models were subjected to 3 cyclic load levels in a series of 6 periods of 10 minutes of work spaced by 10 minutes of rest followed by 7 hours of rest. Multifidus electromyography (EMG) and lumbar displacement were statistically analyzed after processing. RESULTS: Delayed muscular hyperexcitability was observed only in moderate (40 N) and high (60 N) loads (P<0.0001) but was absent in low (20 N) loads. The magnitude of the delayed hyperexcitability was found to be higher (P<0.0001) in the high (60 N) loads compared with the moderate (40 N) loads. CONCLUSIONS: Exposure to moderate and high loads in cyclic (repetitive) work results in an acute neuromuscular disorder indicative of soft tissue inflammation that may become chronic with further exposure. [Description provided by NIOSH]
• Subjects:
  Animals Cumulative Trauma Disorders Epidemiology Musculoskeletal Diseases Musculoskeletal System Nervous System Nervous System Diseases Occupational Health Risk Assessment Risk Factors Safety

  More +
• Keywords:
  Animal-studies Back-injuries Cumulative-trauma-disorders In-vivo-studies Mathematical-models Muscles Muscular-disorders Musculoskeletal-system Musculoskeletal-system-disorders Neuromotor-system-disorders Neuromuscular-system-disorders Risk-factors Statistical-analysis

  More +
• ISSN:
  1076-2752
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Colorado ; Louisiana ; OSHA Region 6 ; OSHA Region 8
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  375-387
• Volume:
  49
• Issue:
  4
• NIOSHTIC Number:
  nn:20032196
• Citation:
  J Occup Environ Med 2007 Apr; 49(4):375-387
• Contact Point Address:
  Moshe Solomonow, PhD, MD (Hon), Musculoskeletal Disorders Research Laboratory, University of Colorado Health Sciences Center, 12800 East 19th Avenue, RC-1, North Tower, Mail Stop 8343, Box 6511, Aurora, CO 80045
• Email:
  Moshe.Solomonow@UCHSC.edu
• Federal Fiscal Year:
  2007
• Performing Organization:
  Louisiana State University, Health Sciences Center, New Orleans, Louisiana
• Peer Reviewed:
  True
• Start Date:
  20000501
• Source Full Name:
  Journal of Occupational and Environmental Medicine
• End Date:
  20031030
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:d905c040b1f46b7bdc14997dba97f5e67b5494e841cdc97761756aa8ec7b6a0b39ab78a2cfad4fd591acb33146ceae52f50f8bd42ef47e94cb09b114cf351fe1
• Download URL:
  https://stacks.cdc.gov/view/cdc/186235/cdc_186235_DS1.pdf
• File Type:
  [PDF - 899.61 KB ]