1. Ergonomics Evaluation of Biomechanical Overloading among Fresh Fruit Bunch (FFB) Harvesters and Loaders in Oil Palm Plantation
1Sukadarin, E.H., 1Deros, B.M., 1Mokhtar, M.M., 1Nawi, N.S.M., 2Tamrin, S.B.M., 3Bakar, S.A. and 4Rambely, A.S.
1Department of Mechanical and Materials Engineering, Faculty of Engineering and Built Environment , Universiti Kebangsaan Malaysia
2Department of Community Health, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia
3 School of Mechatronic Engineering, Universiti Malaysia Perlis
4Department of Mathematical Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia
INTRODUCTION
The core manual activities of oil palm workers are to cut the fresh fruit bunches (FFB) and pruning fronds, collect the loose oil palm fruits and loading/ carrying FFB from ground to wheelbarrow as shown in Figure 1. For short palms (< 3m height), to harvest the FFB and to cut fronds, chisel is used by aiming the sickle at bunch stalk or frond base. To ensure that bunches or fronds is fully cut, force coming from very high speed chisel is required. After cutting the FBB from palm tree, any dropped bunches and loose fruits should be collected. Loose fruits normally are collected by hand picking or racking. If hand picking, stooping and squatting are usually practiced. The weight of matured FFB normally around kg each. More than a bunch of FBB need to be lifted and managed. In total, more than 1000kg of FFB need to be managed daily. Therefore the objective of this study is to evaluate the biomechanical overloading of each core working activities among oil palm harvesters and loaders using OCRA checklist.
RESULT & DISCUSSION
Subjective Evaluation
Fifty six oil palm harvesters and loaders had participated in the study. Their average age is 28 years old. Based on the self-report survey, large majority (94%) of them are facing and experiencing musculoskeletal problems. However, only 21.4% of them have their musculoskeletal problem been diagnosed and verified by the medical officer.
Harvesters and loaders complaints towards musculoskeletal symptoms
Figure 2 shows the highest percentage of discomfort complaints were reported at the knee area (59%). It is followed by the lower back and upper back area with 50% and 47% respectively. Meanwhile, the other body areas have recorded less than 40% discomfort complaints.
Figure 1 Daily work activities of oil palm harvesters and loaders
Cutting FFB and frond
Collecting loose fruits
Loading FFB
Figure 2 The percentage of discomfort of body area experienced by workers
OCRA checklist (evaluation of the final checklist for the work )
(recovery score + frequency score + force score + posture score) x multiplier for the total duration of repetitive tasks
Table 1 OCRA checklist of works activities
Activities
FREQUENCY
POSTURE
FORCE
ADDITIONAL
OCRA CHECKLIST
RISK LEVEL
CONSE-QUENCES
Right
Left
BOTH
Cutting FFB
/ frond
4.5
2.5 6
3.5 32 8 3 2
43.23
15.20
High Risk
Presence of Risk
Re-design the tasks
Collecting loose fruits 11 1
18.53
14.25
Loading /
carrying FFB
46.08
METHOD
Study design
A cross-sectional study was conducted at oil palm plantation located at Negeri Sembilan. Face-to-face interviews, video recording and direct observation were performed.
Subjective Evaluation
Harvesters’ and loaders’ information were gathered using pre-screening questionnaire. Workers’ complaint towards Musculoskeletal symptoms also accounted in the survey.
OCRA Checklist
OCRA checklist analysis was conducted by examining the recorded video of oil palm workers activities. It is important to carefully analyze the frequency, stereotypic nature and posture in the analysis. The analysis is based on normal working hours, 26 days, 8hours working including 1 official break (30 minutes) and 1 additional break (15 minutes).
The biomechanical overloading risk was calculated precisely by using the OCRA checklist. Based on the harvesters’ and loaders’ complaints, more than half of respondents have reported experiencing discomfort at the knee area. However, further investigation using OCRA checklist cannot be done because the focus of the OCRA checklist is towards upper limbs exposures. The frequency, posture, force and the additional factor (e.g. contact stress) scores for both right and left upper limbs of oil palm harvesters and loader have been obtained and calculated separately. The final OCRA scores indicate that a high risk level for musculoskeletal disorders for the selected activities. Therefore, re-design the tasks is required.
CONCLUSION
Reference
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2. Colombini, D., Occhipinti, E., Montomoli, L., Cerbai, M., Fanti, M., Ruschioni, A., … Alvarez, E. (2007). Repetitive movements of upper limbs in agriculture : set up of annual exposure level assessment models starting from OCRA checklist via simple and practical tools . In International Conference on Agriculture Ergonomics in Developing Countries, AEDeC.
3. Madia, H., Elena-Ana, P., Florina, G., & Delia, C. (2006). The OCRA Score and The Risk Evaluation of Musculoskeletal Disorders in a Group of Textile Industry Workers. Cercetãri Experimentale & Medico-Chirurgicale, (3), 212–215.
Contact :
Ezrin Hani Sukadarin