High Force Reaching Task Induces Widespread Inflammation, Increased Spinal Cord Neurochemicals and Neuropathic Pain

Details

• Personal Author:
  Amin M ; Amin S ; Barbe MF ; Barr AE ; Clark BD ; Elliott MB
• Description:
  Repetitive strain injuries (RSI), which include several musculoskeletal disorders and nerve compression injuries, are associated with performance of repetitive and forceful tasks. In this study, we examined in young, adult Sprague-Dawley rats, the effects of performing a voluntary, moderate repetition, high force (MRHF; nine reaches/min; 60% maximum pulling force) task for 12 weeks on motor behavior and nerve function, inflammatory responses in forearm musculoskeletal and nerve tissues and serum, and neurochemical immunoexpression in cervical spinal cord dorsal horns. We observed no change in reach rate, but reduced voluntary participation and grip strength in week 12, and increased cutaneous sensitivity in weeks 6 and 12, the latter indicative of mechanical allodynia. Nerve conduction velocity (NCV) decreased 15% in the median nerve in week 12, indicative of low-grade nerve compression. ED-1 cells increased in distal radius and ulna in week 12, and in the median nerve and forearm muscles and tendons in weeks 6 and 12. Cytokines IL-1a, IL-1β, TNF-a, and IL-10 increased in distal forearm bones in week 12, while IL-6 increased in tendon in week 12. However, serum analysis revealed only increased TNF-a in week 6 and macrophage inflammatory protein 3a (MIP3a) in weeks 6 and 12. Lastly, Substance P and neurokinin-1 were both increased in weeks 6 and 12 in the dorsal horns of cervical spinal cord segments. These results show that a high force, but moderate repetition task, induced declines in motor and nerve function as well as peripheral and systemic inflammatory responses (albeit the latter was mild). The peripheral inflammatory responses were associated with signs of central sensitization (mechanical allodynia and increased neurochemicals in spinal cord dorsal horns). [Description provided by NIOSH]
• Subjects:
  Animals Biomechanical Phenomena Chemistry Epidemiology Ergonomics Immune System Laboratories Musculoskeletal Diseases Musculoskeletal System Nervous System Nervous System Diseases Occupational Health Safety Sense Organs Skin

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• Keywords:
  Animal-studies Author Keywords: Spinal Cord Biological-effects Biological-monitoring Biomechanics Chemical-reactions Cytokines Diseases Immune-system-disorders Immunology Injuries Laboratory-animals Laboratory-testing Macrophages Mechanics Motion-studies Muscle-function Muscle-tissue Muscular-disorders Musculoskeletal-system-disorders Musculoskeletal Disorder Nerve-function Nerve Injury Nervous-fatigue Nervous-system-disorders Neurological-diseases Neuromotor-disorders Neuromotor-function Neuromotor-system Neuromotor-system-disorders Neuromuscular-system-disorders Repetitive-workSensory-motor-system Repetitive Strain Injury Sensory-disorders Skin-sensitivity Spinal-cord Spinal-cord-disorders

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• ISSN:
  0306-4522
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 3 ; Pennsylvania
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  158
• Issue:
  2
• NIOSHTIC Number:
  nn:20035280
• Citation:
  Neuroscience 2009 Jan; 158(2):922-931
• Contact Point Address:
  Melanie Elliott, Department of Physical Therapy, Temple University, 3307 North Broad Street, Philadelphia, PA 19140
• Email:
  melanie.elliott@jefferson.edu
• Federal Fiscal Year:
  2009
• NORA Priority Area:
  Manufacturing ; Construction
• Performing Organization:
  Temple University
• Peer Reviewed:
  True
• Start Date:
  20000601
• Source Full Name:
  Neuroscience
• End Date:
  20120731
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:f30180c8e8adeb4c827752e132ce2daeb91958b87efa0567f0d08c389ec223f404a0de260c641073f7a386fdfe3fe5b953f140ac390019abdbbad6b65d2dbf71
• Download URL:
  https://stacks.cdc.gov/view/cdc/187191/cdc_187191_DS1.pdf
• File Type:
  [PDF - 892.31 KB ]