rwl: Recommended Weight Limit and Lifting Index

In dwnadler/rEHS: A set of tools for EHS management

Description

The primary product of the NIOSH equation is the recommended weight limit (RWL), which defines the maximum acceptable weight (load) that nearly all healthy employees could lift over the course of an 8-hour shift without increasing the risk of musculoskeletal disorders (MSD) to the lower back.

Usage

rwl(horizontal.dist, vertical.dist, distance, angle, seconds.between.lifts,
    grasp, object.weight)

Arguments

horizontal.dist	horizontal location of the object relative to the body (cm)
vertical.dist	vertical location of the object relative to the floor (cm)
distance	distance the object is moved vertically (cm)
angle	the asymmetric angle is the amount (in degrees) of trunk and shoulder rotation required by the lifting task. Angle must be input as 90, 60, 45, 30, or 0
seconds.between.lifts	time between lifts in seconds (s). Time must be entered as 300, 60, 30, 15, 10, or 6
grasp	quality of the workers grip on the object (1 = good, 2 = fair, 3 = poor)
object.weight	weight of the object in kilograms (kg)

Examples

## rwl(45, 25, 40, 0, 15, 1, 20)
## a worker is 45 cm from an object horizontally,
## object is 25 cm above the floor
## and must be lifted 40 cm up.
## worker is positioned 0 degrees relative to the object
## and has a good (1) grip.
## object weighs 20 kg.
## variable LI (lifting index) is created (5.328).
## variable weight.limit is created (3.75).

## LI interpretations:
## <=1: very low risk
## 1.01 - 1.50: low risk
## 1.51 - 2.00: moderate risk
## 2.01 - 3.00: high risk
## >3.01: very high risk

## weight.limit interpretation:
## the acceptable maximum weight (kg) that is safe under the
## horizontal, vertical, and distance data input in the rwl() function,
## including the angle, seconds between lifts, and grasp.

dwnadler/rEHS documentation built on Dec. 20, 2021, 2:16 a.m.