ML. 10, NO. 15, AUGW2015 lSSN 1819-6608

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82006-M15&ian Renard PuWinO Nelvmrk (ARPN]. UI mhk mmd.

MUSCULOSKELETAL DISCOMFORT AMONG WORKERS IN MOULD MAKING MANUFACTURING INDUSTRY

MohdNasruIl Abdol Rahmanl, U loo Hui ', Reazul Haq Abdul Haql, Mohd F h l Hassan: Ahmad Mubarak Tajul ArifiuZ, Muhamad Zaini YunosZand Sharifah Adzil8

'Deparlment of M s n u ~ n g and Lndustrial Engineerin& Uaivmiti Tun Hussein Om Malaysia, Johor, Malaysia -mpartmentof Material and Desiw Enginaring, Facullyof Mechanical and Manufacturing Engineer@ Universiti Tun Hussein OM

Malaysia, Johor, Malaysia %Mail: ~ r u l l ~ t h m . e d a m y

ABSTRACT Mould making industry is a manufacturer and designer for various kinds of mould such as commodity mould,

packaging mould and furniture mould for other manufachuing processes. Due to the mould manufacMing process, a workers are exposed to the risks of upper limb disorders such as repetitive tasks, unmmfortable work poshlres and carry out work for long periods without break. Therefore, the main objective of this study was to identify the prevalence of work-related musculoskeletal disorders among the employee at mould making manufucturiog industry. Structured interview using ComeU Musculoskeletal Diseomfoa Questionnaires (m) were conducted over 35 workers in mould making industry in which the age range was h m 23 to 38 years (mean 28.54 + 4.22 years) while working experience ranges h m 1 to 11 years (mean 4.31 years + 3:09). The results shows that workers in the mould making industry were exposed to ergonomic risk of experiencing discomfort in the upper part of the body such as neck, back body, forearm and wrists that involves an iterative pmms on a regular basis and work in awkward postures. As a conclusion, this study can be a useful references to ergonomists, researchers, OSH practitioners and others concerned to identify the prevalence of work-related musculoskeletal disorders in the workplace, especially in the mould making indushy and other mannfacturing industries.

Keyrordn: musculoskeletsl disardcrn, diswmfaa, mould manufachlring industry.

1NTRODUCTM)N of work-related musculoskeletal disorders 0 s ) Mould making industry is a manufacturer and among the employee at mould making industry.

designer for various kinds of mould such as commodity mould, packaging mould and furniture mould for other MATERIALSAND METHODS manufacturing processes (Canis, 2012). Mould is a commonly term used to describe the equipment for QaestionnaireSurvey producing plastic parts in the mould (Taylan et a1. 2001). m e questionnaire is a "tool" used to gather and In addition, mould is indispensable tool in mass obtain i n f o d o n on knowledge, specific issues of production because it represents a vital link in the chain of impoaance by respond- (Bird, 2009). It should always production of discrete parts for various industries (Lyu et have a purpose related to the objectives (Hawkes & Rowe, nl. 2006). 2008). This study was using the Cornell Musculoskeletal

M d d manufa- by two main memods: DiscomforI Questionnaires (Hedge, 1999). It conventional machining and modem machining. consists of three parts, namely personal information, job Conventional machining processes is the procffs by using tasks and other information as well as the body discomfort several typx of machines such as lathe machine, milling checklist. Part 1 is about the personal information of machimes and grinding machines Modem machining respondents who participated in this study and it is a process refers to machining via Electrical Diharge general questions related to the age, sex, weight and Machine (DM) and Computer Numerical Control (CNC) height. (Arnorim & Weingaremer, 2009. In Part 2 discussed the common activities

Due to the mould manufacming pmcess, a perhned by workers involving qetitive pmcesses, the worker can expose to the risk of Upper Limb Disorders t y p of task being performed, breaks and other information (ULDs) (Pourmahabadian et al. 2006). It was found that such as awareness of health and safety rules as well as the risk of ULDs are associated with various risk ihors envimnmental factors. This section focuses on student such as repetitive tasks, uncomfortable work posblres and opinions and proposals in the workplace. The purpose of carry out work for long periods without breaks (Graves el this section is to suggest how to irnpmve performance in a[. 2004). Work that reqnim activities involved repetitive the workplace and it is an open-ended questions. Part 3 is movements of the uvver limbs such as shoulder. neck. and used to study the discomfort assessment of symotoms or arms is common in-& manufacturing sector (solid& et discomfort e&riencedhy workers. CMDQ -be usedto al. 20101. This m e of activitv involved the uooer limb is make assessments of musculoskeletal disorders. The

.A A.

called repetitive work or work cycles consisting of a purpose of this quehonnaire is to document whether there sequence of tasks @anuta et a!. 22004 Therefore, the is a trend in discomfort, pain and injury among workers in main objective of this study was to identie the prevalence mould making industries (Janson el al., 2010).

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Data collectton i 8.31 kg. Range for height was 163 to 173 and the weight Questionnaire were distributed to employees in was h m 53 to 78. Table1 shows the personal

the mould making industry during a site visit. Interviews information of respondents in the mould making industry were conducted with the respondents to obtain feedback involved in the survey. on the frequency of diswmfort following a liker scale from 0 (no) to 10 (several times a day) and the level of Table-1. Personal information of respondents in mould diswmfort 6nm 1 (little nnwmfortable) to 3 (veq making industry. uncomfortable). In addition, the level of discomfort affect the work fmm 1 (no interference) to 3 (significant interference with the work). Total score discomfort calculated using the formula: Score = fiquency of disenmfoa x level of discomfort caused d i i t i o n to the work (Jamen ef al., 2012). The format of the questionnaire for this studv was a combition of ooen-aded auestions (Reja ef al., 2003). Respondents would give their Job twks and others ioform.tion comments on both positive and negative aspects of their A total of 76.9% of rapondents doing the same works in wor@Lace. They are to give job for a long wbile 10.23% did not carry out work on the some recommendations to resolve any pmbl- long tam In addition, 100% of respondents said that the enwnnte* F i ~ l shows the flow chart of the wnrk done invnlves nn i-be nmcmq R4.6Z0/n of questionnaire survey.

. . - -- -- ..- -. . - - . -- -- .- .- .- . - r.. . ... . . . . - . . . . resmndents said that much of their work at the same lace a$ 15.38% of the respanden& are not. Four di&t tasks such as boring process, tapping process, grinding process and milling process were selected in this study (Figure-2).

Fipu-2. W i t tasks in moulding manufactuting industry; (a) boring process; (b) tapping process; (c)

grinding process and (d) milling process. figure-1. Flow chart of questionnaire survey.

The results obtained from this sbldy show that a Data analysis total of 13 (100%) of respondents would cany on the work

After collecting data through questionnaires, the intaminable threaded screws, 11 (84.62%) respondents results of CMDQ were analyzed using Statistical Package for grinding work, 8 (61.53%) to work bore and 3 for Social Sciences (SPSS) Version 16. Ikscriptive (23.08%) for grinding work TabIs2 shows the analysis of statistics were obtained and the frequency distribution, questionnaires for work assignments and others mean and standard deviation were also be calculnted. information.

RESULTS AND DISCUSSION

Persood information The sample of this study consisted of all men and

the age range was h m 23 to 38 years (mean 28.54 i 4.22 years) while working experience ranges h r n 1 to 11 years (mean 4.31 years i 3:09). Mean (I. Standard Deviation) height and weight of the study was 168.15 * 4.2 cm, 65.85

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Table-2. Job tasks and othen information. Musculnskeletal d i m f o r t survey for task 2 The sewnd task o h carried out in the mould

making industry known as a tapping pmcess. Tap is a type of hand tools used to create threads in a threaded screw holes drilled as an example nut (Hardik et a[., 2012). The total swle discomfort for Task 2 was shown in Figure-3, where about 19.55% of respondents feel mwmfortable or pain in the wrists and 13.67% on the forearm when canying out this pmcess. 12.42% of respondents felt mwmfortable at the lower back the rear and 8.71% in the neck. In addition, only 1.63% of respondents reported discomfort in the shoulder end 1.64% on the upper arm. Diswmfort in the lower part of the body is little where only 1.74% in the thigh, knee (0.06%) and lower leg (0.17%).

Masculoskeletat diswmfort survey for task 1 Task 1 known as a boring process. Boring

process is a reamer operations that have been drilled in advance. Based on the total swre of the diswmf& from CMDQ (Figure-2), it was found that workers in the mould making industry are exposed to discomfort in the upper pat of the body, especially in the wrist (21.22%), forearm (12.42%), upper arm (2.38%). neck (421%) and shoulder (3.06%). A total of 11.06% of respondents felt mwmfortable in the lower back and 2.67% on the upper back. Meanwhile, d y a tittle amount of diswmfort in the lower limbs such as the thigh (1.88%), knw (0.03%) and leg (0.03%).

Figu-2. Musculoskeletal discomfort survey for Task 1.

Figure-3. Musculoskeletal diiswmfort survey for Task 2.

Musculoskeletal discnmfort survey for task3 Task 3 known as a grinding pmcess. This pmcess

is often d e d out after machining or b o ~ g process to obtain a finishing or smooth surface. The scores of diswmfort from Task 3 (Figure-4) shows that 97.22% of respondents repoaed discomfoa in the upper part of the body such as the wrists (23.70%), f o m (1 1.80%), neck (7.98%) and Lower back (9.92 %). A small amount of discomfort reported in the shoulder (1.20%), upper back (2.01%) and upper arm (1.96%). In addition, respondents also felt a little discomfort in the thigh (OH%), knee (0.27%), leg (0.15%) and foot (0.12%) when performed the grinding pmcess.

Figure4 Musculoskeletal discomfoa survey for Task 3.

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m Musculoskeletal diswmfort survey for task 4 REFERENCES

Task 4 known as a milling process. Milling is the process in which various forms of metal machined to the [I] Amorim F. L. and Weingaertner W.L. 2004. Die desired shape a to get a flat surface (Memig & S i Electrical Diiharge M a c h i i of a High- Stoeckhert, 2013). From the Figures, about 30.8% of Seength Copper-Bared AUoy for Injection Molds. respondents felt uncomfortable at wrists and 9.35% on Joumal of the Brazilian Society of Mechanical lower back. In addition, a slight dismmfort in the neck Sciences and Engineeringi, Vol. 26, No. 2, pp. 137- (7.13%), f o m (3.37%), upper arm (1.23%) and 144. shoulder (1.19%) were reported for the milling process. A total of 8.62% discamfort reported at the lower part of the [2] Bird D. K 2009. The use of questionnaires for body such as thigh (3.37%), knee (0.88%), and leg nupiring information on public perception of natural (0.07%) dnring the milling process. hazards and risk mitigation - a review of cumnt

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[3] Canis B. 2012. The Tool and Die Industry: Conhibution to U. S. Man-g and Federal Policy Consideration. CRS Report for Congress.

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Figure-5. Musculoskeletal discomfort survey for Task 4.

Shldy limitatioms Since this study design was case study, the small

sample size among 35 workers in mould making manufacturing indusw have been conducted. This sample size is considered to be ade4nate according to Diem (2012) for such smvey. Therefore a larger sample size is needed for the cross sectional study and others that related to compare between industry sectors.

CONCLUSIONS These results shows that workers in the mould

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[61 Graves R I., Kissten W., Riley D., Lawton C. and Maris L. 2004. Development of risk filter and risk assessment worksheet for HSE guidance - "Upper L i b Disorders in the workplace" 2002. Applied Ergonomics, Vol. 35, pp. 475-284.

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ACKNOWLEDGEMENTS [10]Jansen K., Luik M., Reinvee M., Viljasw V., Ereline

This research is funded by Universiti Tun I., Gapeyeva H. and Paasuke M. 2012. Hussein Onn Malaysia 0 under Short Term Grant Musculoskeletal Discomfm in Production Assembly

(STG, Vot U122). Appreciation also express to the mold Workers. Acta Kinesiologiae Universitatic Tarturnsis,

maldne industw for their ~ o ~ e r a t i o n to conduct this Vol. 18, pp. 102-110.

research at theii.wmkplace.

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