Redesign of Ergonomic Worktables in Reinforced Concrete Sheet

Works Reduce Ergonomic Risk Level

M. Yusuf

, Lilik Sudiajeng, Kadek Adi Suryawan and I Made Sudana

Politeknik Negeri Bali, Jln Kampus Bukit Jimbaran, Badung, Bali, Indonesia

Keywords: Ergonomic Redesign, Tetrapod, RULA, Ergonomic Risk Factor.

Abstract: Iron work in the implementation of reinforced concrete work has ergonomic hazards or high potential hazards,

including unnatural work posture (squatting, bending, turning the body repeatedly) in a relatively long time.

The accumulation of unnatural work postures for a long time can cause premature fatigue, decreased work

speed, level of accuracy, level of alertness, and the degree of health of workers which leads to a decrease in

work productivity. Previous research showed that the analysis of work posture in reinforced concrete using

the RULA method resulted in a RULA score of 7 (seven) and the Ergonomic Risk Factor measurement was

9 (nine), which means that these working conditions have a very high potential hazard that can cause skeletal

muscle complaints. Musculoskeletal Disorders – MSDs) and require immediate improvement of working

conditions. For this reason, research is carried out in the form of controlling potential hazards by redesigning

existing tetrapods so as to reduce the score of potential ergonomic hazards and the tetrapod can be used not

only for beam work but for all types of reinforced concrete work. The measurement of the potential hazard

score was carried out in two ways, namely using RULA and using ergonomic risk factor assessment SNI

9011: 2021. The results showed that there was a decrease in the RULA score from 7 to 5 and a decrease in

ergonomic potential hazard from a score of 9 to 4. It was concluded that the redesign of the work desk

Ergonomics reduces the level of ergonomic risks factor.

1 INTRODUCTION

Industry in the field of Civil Engineering and

Mechanical Engineering, including the construction

world, still contributes the most to the number of fatal

work accidents, not only in developing countries, but

also in developed countries such as Europe. Eurostat

(Jones, 2019) reported that the construction industry

contributed the highest fatal accidents reaching more

than 20%. Meanwhile, the ILO (ILO, 2015) also

reported that construction work accidents were partly

caused by a lack of training and experience on OSH.

In Nairoby-County Kenya, 74% of workers injured or

killed when accidents occur are under the age of 40,

occurring during the busiest hours (10-11am, and 3-

4pm). Falls from heights and being hit by falling

objects account for about 64% of all construction site

accidents. Referring to BPJS Employment data, the

number of work accidents in the construction sector

in Indonesia has always been in the range of 32%

(Manuaba, 2006; Ministry of Manpower of the

https://orcid.org/0000-0002-8238-5543

Republic of Indonesia, 2018). The ILO reports that

work-related fatalities are much higher than fatal

occupational accidents (ILO, 2015). Fatal work-

related illnesses account for about 86% while fatal

work accidents are only around 14%. The type of

occupational disease with the largest cost

compensation is muscle complaints or injuries

(Musculoskeletal Disorders – MSDs). Previous

research on ergonomic studies for reinforced concrete

work shows that the work posture of reinforced

concrete iron shows a RULA score of 7 which means

it has a very high potential for MSDs hazards and

requires immediate improvement of working

conditions (Sudiajeng et al., 2018).

Based on the results of this research, ergonomics

innovation has been carried out in stages to improve

the working conditions of reinforced concrete work.

Reinforced concrete work consists of iron work,

concrete molds and casting. Ergonomics innovation

begins with designing work aids for beam iron work,

namely in the form of a tetrapod designed based on

370

Yusuf, M., Sudiajeng, L., Suryawan, K. and Sudana, I.

Redesign of Ergonomic Worktables in Reinforced Concrete Sheet Works Reduce Ergonomic Risk Level.

DOI: 10.5220/0011806000003575

In Proceedings of the 5th International Conference on Applied Science and Technology on Engineering Science (iCAST-ES 2022), pages 370-374

ISBN: 978-989-758-619-4; ISSN: 2975-8246

worker anthropometry. The tool is used as a

workbench for reinforcing reinforced concrete beams

and has been proven to improve static sitting work

postures to dynamic standing work postures, reducing

the risk of MSDs from the high category (Rula score

7) to the medium category (Rula score 4) and

reducing the need for the number of workers from 7

(seven) people to only 2 (two) people)/beam. Iron

work in building construction is very diverse, starting

from beam and column work as well as foundation

and floor plate work.

every worker problem needs to be intervened.

Ergonomics intervention will provide an effective

solution for workers as well as for company

management (Bridger, 2008; International

Ergonomics Association, 2020; Kroemer &

Grandjean, 2009). The problem of workers is not only

in work posture but also in occupational health, it is

also necessary to provide a solution to the problem

(Edem, Akpan, & Pepple, 2017; NIOSH, 2015;

Stanford, 2016).

This research is a continuation of previous

research with a focus on ergonomics innovation for

plate iron work which has different characteristics

from beam/column work, in terms of design, level of

difficulty, and dimensions. Through this research, it

is hoped that an ergonomic workbench can be created

in the form of a portable, flexible, inexpensive work

table, and can be used not only for beam/column

work, but for all types of reinforced concrete work.

One of the characteristics in the application of total

ergonomics is solving multidisciplinary problems, so

it requires disciplines from mechanical engineering to

redesign ergonomic workbenches and civil

engineering to construction work.

2 METHOD

This research was carried out with an experimental

design using the Control Group Design method.

Subjects consisted of 2 (two) groups, namely the

control group who carried out the foundation plate

ironing work with old working conditions before the

ergonomic intervention was carried out (P1) and the

treatment group (P2) which carried out the foundation

plate ironing work with new working conditions after

the intervention. ergonomics.

The ergonomic intervention carried out was to

redesign the work table according to student

anthropometry so that it could be used for reinforced

concrete work or foundation plate reinforcement. The

research sample is a student of the Department of

Civil Engineering at the Bali State Polytechnic who

is taking reinforced concrete reinforcement practice.

The number of samples was 50 people, the P1 group

was 25 students and the P2 group was 25 students.

Ergonomic hazard level measurement is carried out in

two ways, namely using the Rapid Upper Limb

Assessment (RULA) and using the Ergonomic Risk

Factor (ERF) Assessment SNI 9011 in 2021. Data

analysis was carried out in a quantitative descriptive

manner by comparing the RULA and ERF scores

before and after repairs.

3 RESULTS AND DISCUSSION

3.1 Subject Anthropometric Analysis

The research subjects were Civil Engineering

students who practiced reinforced concrete work as

many as 50 students. Anthropometry of the student

body is measured as the basis for redesigning the

workbench on reinforced iron work. The results of

student anthropometric measurements are as follows.

Table 1: Anthropometric Data of Research Subjects.

measured

component

Mean SD

percentile

5 50 95

Standing height 168,07 6,20 162,20 165,30 177,00

Standing elbow

heigh

105,82 6,70 95,10 104,65 116,50

Sitting height 87,85 2,99 84,00 86,95 93,00

Sitting elbow

heigh

24,38 2,70 19,70 24,65 28,20

Buttock-knee

length

56,71 2,31 54,00 56,35 59,70

Popliteal buttock

length

46,96 1,97 44,30 47,20 49,20

Knee height,

sitting position

49,66 2,23 46,80 49,60 52,90

Popliteal height,

sitting position

42,48 1,57 40,30 42,35 44,20

Shoulder-elbow

length

35,37 2,60 31,70 35,80 38,70

Elbow to fingertip

length

45,75 2,00 43,20 45,40 48,50

hand length 17,31 0,41 16,70 17,30 18,00

hand width 10,46 0,39 9,90 10,45 11,20

Reach ahead 72,06 2,36 68,50 72,65 74,30

SD: Standard Deviation

Worker anthropometry data is very important to

design the tools used in work, so that the tools can be

used optimally by workers if they are adjusted to the

user's anthropometry (Budiyanto, Adiputra, Sutjana,

& Tirtayasa, 2019; Kamat, Md Zula, Rayme,

Shamsuddin, & Husain, 2017)

Redesign of Ergonomic Worktables in Reinforced Concrete Sheet Works Reduce Ergonomic Risk Level

371

3.2 Work Tool Redesign

The redesign of the ergonomic workbench on the

reinforced concrete slab iron work is a redesign of the

previous workbench which is not in accordance with

the user's anthropometric size. Redesign of work aids

in the form of a tetrapod that is portable, flexible,

adjustable and multi-functional, namely as a

workbench for the assembly of structural beams and

columns. The height of the tetrapod can be adjusted

according to the user's comfort level. Aside from

being a beam and column assembly workbench, in a

reclining position it can also be used as a plate

assembly workbench by adding a work board on it.

The redesigned image of the tetrapod workbench is as

follows.

Figure 1: Tetrapod workbench design.

In accordance with the user's anthropometry, the

height of the table can be adjusted between 60 - 90

cm, while the width of the table according to the reach

is 60 cm and the length is 103.9 cm.

3.3 RULA Analysis

Analysis of upper body posture in workers can be

measured using the RULA method. The evaluation of

the RULA method is as follows.

Table 2: RULA Grand Grand Score Evaluation.

Grand

Score

Score = 1 - 2

Posture Acceptable if not

maintained or repeated for

long periods

Score = 3 – 4

Further investigation is need

and changes may be required

Score = 5 – 6

Investigation and changes are

required soon

Score = 7

Investigation and changes are

required immediately

The results of the calculation of the RULA score are

as follows.

Figure 2: Calculation of RULA Score.

Based on the results of the RULA calculation, it was

obtained that before the RULA score was corrected,

a grand score of 5 was obtained, this indicates that a

score of 5-6 means that investigation and change are

required soon, after using the redesign of the tetrapod

table, the grand score decreased to 3, which means

that the grand score is 3-4 further investigation is

needed and change may be required.

Measurement using RULA analysis is one way to

determine the level of ergonomics hazard so that it

can be used in providing interventions on changes in

work posture, both before and after the intervention

given to workers (Yadi, Kurniawidjaja, & Susilowati,

2018; Yusuf, Adiputra, Dewa, Sutjana, & Tirtayasa,

2016).

3.4 Ergonomic Risk Factor (ERF)

Analysis

Ergonomics risk level assessment is carried out using

Ergonomic Risk Factor SNI 9011 Year 2021 (BSNI,

iCAST-ES 2022 - International Conference on Applied Science and Technology on Engineering Science

372

2021). Risk level assessment before redesign is as

follows.

Table 3: Ergonomic Risk Factor assessment results.

Potential Hazard

Assessment Results

Score

Total

Assessment

Results

Result

Interpretation

Upper

Body

Back

and

Lower

Manual

Weight

Lifting

Before

Repair

7 0 2 9

Score more

than 7

(dangerous)

After

Repair

2 0 2 4

Score between

3-6 (needs

further

observation)

Based on Table 3, the ergonomic risk factor score is

9 which indicates that there is a potential hazard in

reinforced concrete work, and it needs to be

controlled immediately. Control is done by using a

redesigned tetrapod table.

Ergonomics intervention is very necessary in

order to suppress worker problems, both problems

related to muscle complaints, fatigue, and increasing

worker productivity (Budiyanto & Yusuf, 2020;

Deouskar N, 2017; Kasper, 2014). Ergonomics

approach needs to be done both in small industries

and in large companies to increase work productivity

(Manuaba, 2006; Sudiajeng, Adiputra, & Leibbrandt,

2012).

4 CONCLUSIONS

a. The results of the redesign of work aids in the form

of a tetrapod that is protable, flexible, adjustable

and multi-functional, namely as a workbench for

assembling beams and structural columns. The

height of the tetrapod can be adjusted according

to the user's comfort level. Aside from being a

beam and column assembly workbench, in a

reclining position it can also be used as a plate

assembly workbench by adding a workboard on it.

b. The result of measuring the RULA score before

repair is 7 (Investigation and changes are

ruquaired immediatelly) and after repair is 4

(Further investigation is need)

c. The result of measuring the level of ergonomic

hazard risk using SNI 9011 in 2021 is that before

the repair, a score of 9 (Dangerous) was obtained,

while after the improvement, a score of 5 was

obtained (Need further observation).

ACKNOWLEDGEMENTS

The authors would like to thank P3M Politeknik

Negeri Bali and the Indonesian Government's

Ministry of Education, culture, research and

technology for funding this research.

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