The document describes a sample calculation of recommended weight limits and lifting indices using the NIOSH lifting equation. Key details include: - Task variables such as load weight, heights, distances, frequency, duration and coupling are input to calculate multipliers. - Multipliers are used to calculate the recommended weight limit (RWL) at the origin and destination points. - The lifting index (LI) is then determined by comparing the load weight to the RWL. - Initial results show an LI over 1, indicating risk of back pain. The layout is revised by adjusting task variables like shorter distances and lower frequency. - Revised calculations yield safer results with LI values closer to 1. The

1. SAMPLE CALCULATION

2. SAMPLE CALCULATION
The measured task variables when the worker is lifting:-
Load to be lifted= 20Kg
H1(origin)= 40cm V1(origin)= 50cm A1(origin)=0
H2(dest.) = 43cm V2(dest.) =0 A2(dest.) =0
D(dist.)= 50cm F (freq.) = 4 Duration (hrs) =1-2
C(coupl.) = Poor

3. FOLOWING ARE THE
MULTIPIERS:-
AT ORIGIN
HM= 25/H=0.63
VM= 1-(0.003|V-75|)=092
DM=0.82(4.5/D)=0.91
AM=1-(0.0032A)=1
FM (from table)=0.72 CM(from table)=0.9

4. AT DESTINATION
HM= 25/H=0.58
VM= 1-(0.003|V-75|)=0.78
DM=0.82(4.5/D)=0.91
AM=1-(0.0032A)=1
FM (from table)=0.72 CM(from table)=0.9

5. RESULTS
RWL=LC * HM *VM * DM * AM *FM * CM
RWL(origin)=7.8Kg
RWL(dest.) = 6.1Kg
LI(origin)= Load/RWL=2.6
LI(dest.) =Load/RWL =3.3
As the Lifting Index is more than one which indicates
that the worker must be having problem of Low Back
Pain, thus the layout is to be redesigned by redesigning
the task variables

6. REVISION OF THE UNSAFE
RESULTS
THE RESULTS OBTAINED FOR THE
ABOVE SAMPLE ARE UNSAFE. THUS
WORKING LAYOUT IS REVISED BY
REVISING THE TASK VARIABLES IN
ORDER TO HAVE THE SAFER RESULTS
i.e SAFE LOADING CONDITIONS OF THE
WORKER.

7. SAMPLE CALCULATION
The revised task variables when the worker is lifting:-
AT ORIGIN
Load to be lifted= 20Kg
H1(origin)=30cm V1(origin)=50cm A1(origin)= 0
H2(dest.) = 30 cm V2(dest.) =40 cm A2(dest.) =0
D(dist.)=10 F(freq.) =3 Duration(hrs)=1-2
C(coupl.)=Poor

8. AT DESTINATION
HM= 25/H=0.58
VM= 1-(0.003|V-75|)=0.9
DM=0.82(4.5/D)=1
AM=1-(0.0032A)=1
FM (from table)=0.79 CM(from table)=0.9

9. REVISED RESULTS
RWL=LC * HM *VM * DM * AM *FM * CM
RWL(origin)=12.6Kg
RWL(dest.) =12.2Kg
LI(origin)=Load/RWL=1.5
LI(dest.) = Load/RWL=1.6
As the Lifting Index is not less than one ,but the
layout of work has been revised so as to reduce the LI
to maximum possible extent. Thus summarising the
revisions made as mentioned:

10. CHANGES DONE IN THE TASK
VARIABLES
 The worker is advised to be closer to the Origin and
destination points in order to increase the HM
 Raising the height of the Destination Point in order to
increase VM
 Reducing the lifting frequency in order to increase the FM
 Further the LI can also be reduced by reducing the Load to
be lifted

11. SOFTWARE DEVELOPED
FEATURES
 The software has been made in C++ Programming
Language.
 It is used to calculate the RWL & LI using NIOSH
Lifting Equation.
 The input given to the software are the values of Task
Variables.
 The output comprises of the Multipliers along with
RWL & LI.

12. 12

13. Start
Define variables
involved
Initialize desired
variables
Define various functions
A
Read input
data i.e task
variables
Call functions for task
multipliers
B

14. B
NO
NO
If Dur==1 If Dur==2 If Dur==3
YES
YES
YES
Call function for freq.
multiplier for V1
NO
NO
If Dur==1 If Dur==2 If Dur==3
YES
YES
YES
Call function for freq.
multiplier for V2
C

15. C
NO
A Display all the
multipliers
Compute RWL and LI
Display RWL and LI
NO
End
YES
Stop

16. THE RESULTS
ALONG WITH THE
EXECUTION OF THE
PROGRAMME
16

17. Enter the following data
Load to be lifted---
15
Horizontal Distance at origin---
50
Horizontal Distance at Destination---
45
Vertical Distance at Origin---
114
Vertical Distance at Destination---
0

18. Frequency i.e, Lifts per Minute---
3
Asymmetric Angle at Origin---
15
Asymmetric Angle at Destination---
20
What is the type of Coupling
PRESS
1 for Good
2 for Fair
3 for Poor
2

19. What is the Duration of Service
PRESS
1 for <=1 hour
2 for 1 to 2 hours
8 for 2 to 8 hours
2
---------------------------------------------
The Recommended Weight Limit(RWL1) at origin is
6.563798
----------------------------------------------
The Recommended Weight Limit(RWL2) at Destination is
5.97883

20. ---------------------------------------------
The lifting Index at origin is 2.285262
----------------------------------------------
----------------------------------------------
The lifting Index at Destination is 2.508852
----------------------------------------------
MULTIPLIERS ARE AS UNDER
HM VM DM AM FM CM
0.50.8830.8594740.9520.791
0.555556 0.775 0.859474 0.9360.79 0.95

21. THANKS
21