Revised NIOSH Lifting Equation - Fundamentals and Assessment Tools for Occupational Ergonomics - page 869

46
Revised NIOSH Lifting
Equation

46.1 Introduction . ............................ 46-1

46.2 Definition of Terms . . ..................... 46-2

Recommended Weight Limit † Measurement
Requirements † Lifting Index † Miscellaneous Terms
46.3 Limitations of Equation .................... 46-5

46.4 Obtaining and Using the Data . . ............. 46-6

Horizontal Component † Vertical Component † Distance
Component † Asymmetry Component † Frequency
Component † Coupling Component
46.5 Procedures . . ............................ 46-15
Step 1: Collect Data † Step 2: Single- and Multi-Task
Procedures
46.6 Applying the Equations .................... 46-19
Using the RWL and LI to Guide Ergonomics
Design † Rationale and Limitations for LI † Job-Related
Intervention Strategy
46.7 Example Problems . . . ..................... 46-20
Loading Supply Rolls, Example 1 † Dish-Washing Machine
Unloading, Example 2
46.8 Validation of the Revised NIOSH
Lifting Equation .......................... 46-25

Thomas R. Waters
National Institute for
Occupational Safety and
Health

46.1 Introduction

This chapter provides information about a revised equation developed by the National Institute for
Occupational Safety and Health (NIOSH) for assessing the physical demands of certain two-handed
manual lifting tasks, which was described by Waters et al. (1993). The chapter contains sections describ-
ing what factors need to be measured, how they should be measured, what procedures should be used,
and how the results can be used to ergonomically design new jobs or make decisions about redesigning
existing jobs that may be hazardous. The chapter defines all pertinent terms and presents the mathematical
formulae and procedures needed to properly apply the NIOSH lifting equation. Several example problems
are also provided to demonstrate how the equations should be used. An expanded, more detailed
version of this chapter is contained in a NIOSH report entitled Applications Manual for the Revised
NIOSH Lifting Equation (Waters et al., 1994).
Historically, the NIOSH has recognized the problem of work-related back injuries, and published the
Work Practices Guide for Manual Lifting (WPG) in 1981 (NIOSH, 1981). The NIOSH WPG contained a
summary of the lifting-related literature before 1981; analytical procedures and a lifting equation for

46-1