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NIOSH Program Portfolio

 

Manufacturing

NORA Manufacturing Sector Strategic Goals

R013970 - 021H: Force-repetition Interaction in a Rat Injury Model (3970)

Start Date: 8/1/2006
End Date: 7/31/2011

Principal Investigator (PI)
Name: Linda Frederick
Organization: NIOSH
Sub-Unit: OEP
Funded By: NIOSH

Primary Goal Addressed
3.0

Secondary Goal Addressed
None


Attributed to Manufacturing
50%

Project Description

Short Summary

In our previous grant, we explored the short-term effects (3-12 weeks) of such tasks on inflammation and motor behavior, and found that higher demand tasks lead to a cyclical inflammation response with motor declines. Our goal in this competitive renewal is to use our highly innovative and unique animal model of WMSD to identify and characterize cellular mechanisms underlying inflammatory tissue changes associated with long-term performance (18 and 24 weeks) of repetitive and/or forceful reaching. SPECIFIC AIM 1) To determine the extent to which long-term exposure to 2 task regimens, low repetition-low force (LRLF), and high repetition-low force (HRLF) causes tissue changes indicative of inflammation. Specific Aim 2) To determine the extent to which long-term exposure to 2 task regimens (LRLF and HRLF) causes motor behavior changes indicative of inflammation. These proposed experiments are vital for full understanding of the effects of long-term exposure to combinations of risk factors on tissue and motor function, as well as immune cellular mechanisms underlying the inflammatory tissue responses. The data generated by these studies will ultimately contribute to the development of new strategies for effective prevention and management of WMSD.



Description

Work-related musculoskeletal disorders (WMSD) account for 1 in 3 lost work time illnesses. In spite of epidemiological evidence for a positive relationship between exposures to repetitive and/or forceful motion and the prevalence and incidence of WMSD, the mechanisms of pathophysiology are incompletely understood. In our previous grant, we explored the short-term effects (3-12 weeks) of such tasks on injury/inflammation and motor behavior, and found that higher demand tasks lead to a cylical injury inflammation response with motor declines. We also uncovered evidence of adaptive tissue remodeling and pathological reorganization/degeneration, and are expanding our focus to include those tissue responses. Our goal in this competitive renewal is to use our highly innovative and unique animal model of WMSD to identify and characterize cellular mechanisms underlying tissue changes associated with long-term performance (18-30 weeks) of repetitive and/or forceful reaching. SPECIFIC AIM 1) To determine the extent to which long-term exposure to four task regimens, low repetition-low force (LRLF), low repetition-high force (LRHF), high repetition-low force (HRLF), and high repetition-high force (HRHF) causes tissue changes indicative of adaptation, inflammation, or degeneration. Specific Aim 2) To determine the extent to which long-term exposure to four task regimens (LRLF, LRHF, HRLF, and HRHF) causes motor behavior changes indicative of adaptation, inflammation, or degeneration. SPECIFIC AIM 3) To determine if there is a direct relationship between tissue changes and sensorimotor function. These proposed experiments are vital for full understanding of the effects of long-term exposure to combinations of risk factors on tissue and motor function, as well as cellular mechanisms (cell growth, immune, catabolic or cell death) underlying the tissue responses (adaptation, inflammation, or degeneration, respectively). We HYPOTHESIZE that tissue tolerance declines over time if task exposures are sufficient to overload tissues and stimulate repeated inflammation or degeneration. The data generated by these studies will ultimately contribute to the development of new strategies for effective prevention and management of WMSD.



Objectives

Specific Aim 1) To determine the extent to which long-term exposure to 2 task regimens, low repetition-low force (LRLF), and high repetition-low force (HRLF) causes tissue changes indicative of inflammation.



Specific Aim 2) To determine the extent to which long-term exposure to 2 task regimens (LRLF and HRLF) causes motor behavior changes indicative of inflammation.



Page last updated: June 3, 2011
Page last reviewed: May 23, 2011
Content Source: National Institute for Occupational Safety and Health (NIOSH) Office of the Director

 

NIOSH Program:

Manufacturing