Manual Material Handling Activities Research Articles

Ergonomic risks in manual material handling activities and musculoskeletal disorders complaints in the animal feed industry production area in East Java, Indonesia

Introduction: Manual lifting and load transfer processes that are not carried out properly will result in over exertion-lifting and carrying, i.e. body tissue damage caused by excessive lifting. One of the work-related diseases caused by this activity is Musculoskeletal Disorders (MSDs), a disorder that occurs in the muscles, nerves, tendons, ligaments, joints, cartilages, or the intervertebral discs. The study aims to find out the picture of ergonomic risk in manual material handling activity and musculoskeletal complaints. Methods: Data was obtained from two respondents through accidental sampling. The measurement of the lifting index is done with meters and calculated using the formula of the calculation of the lifting index. The instrument for measuring musculoskeletal disorders was the GOTRAK SNI 9011:2021 Questionnaire. Results: Lifting activities performed by the Hand Add section (LI: 3.054-3.228) and Bagging Off (LI: 3.073-3.470) have a Lifting Index value that is in category > 3 so the interpreted activity has a high risk of causing musculoskeletal complaints. Workers who perform manual material handling activities have high complaints of skeletal and muscle disorders in the upper limbs. Conclusion: Manual handling activities performed in the industry have a high risk of causing injury. Workers who perform manual material handling activities are known to have high complaints of muscle and muscle disorders in the upper limbs.

Manual Material Handling Training for Workers in The Furniture Industry

The work processes in the furniture industry starts from wood transportation, construction, sanding, assembling, and finishing. One of the potential hazards that always exist in every work process in the furniture industry is ergonomic hazards. The risks of Manual Material Handling (MMH) that includes lifting and lowering, pushing and pulling, rotating, carrying, and holding against an object adversely affect both the company and workers. This study aims to determine potential ergonomic hazards and control efforts to reduce risk of ergonomic hazards and injuries to furniture industry workers by providing training Occupational Safety and Health and proposed work system during Manual Material Handling activities. The method used to identify is the Hazard Identification Risk Assessment Control (HIRAC) technique. HIRAC used to help provide an understanding of the hazards that exist in each work process to minimize the occurrence of adverse Occupational Diseases. This research is qualitative research with observation and interview data collection techniques. Analysis techniques in this research included data reduction, data presentation, conclusions, and verification. Results of the evaluation showed that the identification of ergonomic hazards in the furniture industry was found in all furniture work processes from wood cutting to finishing.

ANALISIS PENGUKURAN POSTUR KERJA PADA AKTIVITAS MANUAL MATERIAL HANDLING DI PT JMS BATAM

This study aims to analyze the risk level of Musculoskeletal Disorders (MSDs) in workers who carry out Manual Material Handling (MMH) activities at PT JMS Batam. MMH is a manual transportation and material transfer activity using human labor. This study was conducted because MMH activities carried out repetitively often cause health complaints, especially in the skeletal muscles. The primary data collection method is carried out through observation, direct interviews with employees, documentation using mobile phone cameras, and the distribution of Nordic Body Map (NBM) questionnaires to identify complaints on workers' body parts. The Rapid Entire Body Assessment (REBA) method is used to assess the posture of workers during MMH activities. The results showed that Nordic Body Map analysis showed that all stevedoring workers had the potential to experience musculoskeletal disorder complaints, especially on the left shoulder, right shoulder, back, waist, and buttocks. Workers with scores above 70 are at high risk and need immediate improvement. Workers scoring 55-70 are at moderate risk and require consideration of future improvements. Analysis using the REBA method showed that material transfer has a high risk of trunk and upper arm posture, increasing the risk of injury and health problems.

Biomechanical investigation of tasks concerning manual materials handling using response surface methodology

In typical manual material handling, the variations in walking pattern are decided by various factors, such as load being handled, frequency of handling, walking surface, etc. Traditional gait analysis protocols commonly evaluate individual factor within specified ranges associated with particular activities or pathologies. However, existing literature underscores the concurrent impact of multiple factors on gait. This study identifies five pivotal factors—walking speed, surface slope, load carried, carrying method, and footwear—as contributors to gait alterations. To address risk factors in manual material handling activities, we propose a unique design-of-experiment-based approach for multi-task gait analysis. Unraveling the relationship between manual handling attributes and human gait holds paramount importance in formulating effective intervention strategies. We optimized the five input factors across a cohort of 15 healthy male participants by employing a face-centered central composite design experimentation. A total of 29 input factor combinations were tested, yielding a comprehensive dataset encompassing 18 kinematic gait parameters (such as cadence, step length etc., measured using inertial measurement system), the isolated impacts of factors, and the interplay of two-factor interactions with corresponding responses. The results illuminate the optimal scenarios of input factors that enhance individual gait performance—these include wearing appropriate footwear, employing a backpack for load carriage, and maintaining a moderate walking pace on a medium slope with minimal load. The study identifies walking speed and load magnitude as primary influencers of gait mechanics, followed by the chosen carrying method. In consequence, the insights gained advocate for the refinement of manual material handling tasks based on the outcomes, effectively mitigating the risk of musculoskeletal disorders by suggesting the interventions for posture correction.

A Feasibility Study on the Conversion from Manual to Semi-Automatic Material Handling in an Oil and Gas Service Company

In manufacturing companies, manual material handling (MMH) involves lifting, pushing, pulling, carrying, moving, and lowering objects, which can lead to musculoskeletal disorders (MSDs) among workers, resulting in high labor costs due to excessive overtime incurred for manual product preparation. The aim of this study was to show how ergonomic measures were used to reduce the risk of MSDs and to reduce operating costs in the warehouse department of an oil and gas service company. A preliminary study using the Nordic Body Map survey showed that the workers experienced pain in various parts of the body, indicating the presence of MSDs. The researchers then used methods such as the Rapid Upper Limb Assessment (RULA), Rapid Entire Body Assessment (REBA), and National Institute for Occupational Safety and Health (NIOSH) assessments to verify whether the MMH activities had an acceptable level of risk. The results revealed that certain manual material handling (MMH) activities were assessed as low–very high risk, with RULA scores ranging from 3 to 7 and REBA scores ranging from 4 to 11. An immediate solution was to replace the manual process with a semi-automatic process using a vacuum lifter. A feasibility study was conducted using the net present value (NPV), internal rate of return (IRR), and payback period to justify the economic viability of the solution. The analysis indicated that implementing the vacuum lifter not only mitigated the risk of MSDs but also reduced the operating costs, demonstrating its viability and profitability. Overall, this study suggests that implementing a vacuum lifter as an assistive device in the warehouse would be a beneficial investment for both the workers and the company, improving both well-being and finances.

Risk Analysis of Musculoskeletal Disorders Using RWL And LI Methods

Material handling is an activity that is often carried out by everyone in daily activities, especially in activities in a company. Material transfer or material handling without the use of tools, commonly referred to as "manual material handling," can affect a production process in the company. At PT. X, there is a manual material handling activity with a total load of 23 kg, namely taking water treatment analysis samples. This study's goal is to make a recommendation for changing how employees behave at work when taking samples for water treatment analysis. In completing this study, the methods used were the Recommende Weight Limit (RWL) and Lifting Index (Li) methods. according to the results of the recommended weight limit method's calculations, the recommended load weight was obtained with an average weight of 8 kg and was known. And based on Li's calculations, the value of Li > 1 was obtained, It indicates that there is a potential of spinal injury during the activity. So it is necessary to make improvements using manual tools or layout improvements to make it more effective and efficient.

Virtual modelling and analysis of manual material handling activities among warehouse workers in the construction industry.

Musculoskeletal risks (MSRs) are a major concern among construction warehouse workers due to the lifting, carrying and lowering of heavy loads. The objective of this study was to reduce MSRs among warehouse workers in the construction industry using virtual modelling and analysis of activities. A preliminary study was carried out using the Standard Nordic Questionnaire. Biomechanical analysis, Ovako Working posture Assessment System (OWAS) and Rapid Upper Limb Assessment (RULA) were used to analyse the material handling activities. Virtual modelling was used develop the manikins with autoclaved aerated concrete (AAC) blocks at different carriage modes and stacking heights for the analysis. The preliminary study results revealed a higher prevalence of risk at their lower back (73.24%) among the construction warehouse workers. Biomechanical analysis showed a higher risk at L4-L5 joint of lumbar spine during overhead and bending postures for stacking the blocks. Posture analysis results of OWAS indicated a lower risk in overhead carriage mode. Detailed analysis with RULA confirms this result. Mean compressive force values at stacking heights were showed a significant difference (p < 0.05) in 8, 13, 18 and 21 kg AAC blocks. However, stacking height with a range of 120-140 cm was found as safer to the workers by considering all block sizes. An ergonomic intervention based on safer stacking heights was developed to reduce MSRs to an acceptable range. It improves productivity of handling the AAC blocks by reducing the cycle time. The intervention can be adapted for handling of similar materials in the construction industry.

The Effect of Work Posture on Work Fatigue in the Metal Moulding Department of XYZ Company

One of the things that can cause a work accident is manual material handling (MMH). Manual material handling activities are still often found in modern industries because MMH activities are easy to apply, cheap, and very flexible to do. The poor manual activity of material handling can lead to musculoskeletal complaints, spinal cord injuries, and work fatigue. If the worker does his job with a work posture that is not ergonomic then the worker will be vulnerable to work fatigue. Work posture problems and work fatigue are also experienced in XYZ Company which is one of the companies engaged in the metal casting industry. Therefore, the study aimed to examine the effect of work posture on the level of work fatigue in the metal moulding department of XYZ Company using NBM questionnaires, SOFI questionnaires, and REBA methods. The results showed that the segment of the body most felt pain by the operator was the left leg. Wherefrom the results of identification of working posture there is one operator who gets a REBA score of 10 and three operators who get a REBA score of 12. Then, the level of work fatigue from the four operators, namely, amounted to 3.46; 3.21; 2.7; and 3.02. The four values have a value that is in the SOFI score range of 1.13-4.87 which means all four operators experience moderate work fatigue. Then a regression test was conducted to determine the effect of both variables and obtained a correlation coefficient (r) value of 0.754; and a coefficient of determination (R Square) of 0.569. These values show the effect of work posture on work fatigue has a strong relationship and an effect of 56.9%.

Centre of pressure parameters for the assessment of biomechanical risk in fatiguing frequency-dependent lifting activities

Lifting tasks, among manual material handling activities, are those mainly associated with low back pain. In recent years, several instrumental-based tools were developed to quantitatively assess the biomechanical risk during lifting activities. In this study, parameters related to balance and extracted from the Centre of Pressure (CoP) data series are studied in fatiguing frequency-dependent lifting activities to: i) explore the possibility of classifying people with LBP and asymptomatic people during the execution of task; ii) examine the assessment of the risk levels associated with repetitive lifting activities, iii) enhance current understanding of postural control strategies during lifting tasks. Data were recorded from 14 asymptomatic participants and 7 participants with low back pain. The participants performed lifting tasks in three different lifting conditions (with increasing lifting frequency and risk levels) and kinetic and surface electromyography (sEMG) data were acquired. Kinetic data were used to calculated the CoP and parameters extracted from the latter show a discriminant capacity for the groups and the risk levels. Furthermore, sEMG parameters show a trend compatible with myoelectric manifestations of muscular fatigue. Correlation results between sEMG and CoP velocity parameters revealed a positive correlation between amplitude sEMG parameters and CoP velocity in both groups and a negative correlation between frequency sEMG parameters and CoP velocity. The current findings suggest that it is possible to quantitatively assess the risk level when monitoring fatiguing lifting tasks by using CoP parameters as well as identify different motor strategies between people with and without LBP.

Work Facilities Improvement Using Systematic Layout Planning to Reduce the Risk of Manual Handling

Manual material handling (MMH) activity is considered a major ergonomic risk factor in Indonesian Small and Medium Enterprises (SMEs) that leads to the onset or development of musculoskeletal pain, particularly in the low back. It may exaggerate the risk of injury or disorders. This study evaluates the recommended weight limit (RWL) at UD Fatikh Sport, a SMES sports shoe manufacturer. In addition, we also propose a facility layout redesign to reduce the ergonomic risks of manual material handling activities. The NIOSH lifting equation was used to determine the RWL at four departments and during MMH activities. The Lifting Index (LI) of the MMH activity exceeded the recommended value, which might raise the ergonomic risks. The risks worsened because the operator carried the load manually to several departments, which were located separately on the second floor, without any aid tools. Two designs of facility layout improvement were developed using a systematic layout planning (SLP) approach. The first design was focused on minimizing the transportation distance, while the space requirement of each department or MMH activities was emphasized in the second design. It aims to improve working conditions and reduce workers' fatigue. Further research should calculate the productivity and estimate its cost-efficiency before and after implementing the proposed layout.

PERANCANGAN ALAT BANTU DENGAN METODE CONJOINT ANALYSIS DAN QUALITY FUNCTION DEPLOYMENT (QFD) BERDASARKAN PRINSIP ERGONOMI

&lt;p&gt;&lt;em&gt;The industrial sector in Indonesia has experienced rapid development in the last 10 years. The manufacturing industry is the sector that contributes the largest export value at USD 105.11 billion or Rp. 1,438 trillion (exchange rate of Rp. 13,686/USD) during January to October 2019. PT. PJM is a manufacturing company that produces electrical panels. In production activities, PT. PJM still does a lot of work manually or Manual Material Handling (MMH) and has poor work postures. MMH activities and wrong and inappropriate work postures are the main sources of worker complaints that can pose ergonomic risks to workers. Ergonomics intervention in the design of assistive devices is carried out to help prevent the risk of MSDs and ergonomics in the workplace. The purpose of this study was to improve work posture and reduce the risk of MSDs in workers. The results of this study indicate that the highest exposure level is at the welding station, namely 60.79%, which is included in the category that needs further research and changes are made. However, after implementing the design of assistive devices at the welding station, there was a decrease in the exposure level value of 33.59%, which was included in the safe category. The implementation of the design of the tool has succeeded in improving the work posture and the risk of MSDs of workers at the welding station.&lt;/em&gt;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;&lt;em&gt; &lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;

Ergonomic Risk Evaluation of Manual Material Handling in Brick Production

The manual material handling (MMH) activity of making bricks causes workers to use energy throughout their body to do work so that it can pose a potential ergonomic hazard. Ergonomics hazards caused are fatigue in the muscles due to repetitive movements, poor work posture, too heavy load, inadequate tools, unsupportive environmental conditions. Complaints of Musculoskeletal disorders (MSDs) that accumulate will have a major impact on bone structure disorders and muscle disorders.The purpose of this study was to evaluate the ergonomic risks and complaints of MSDs in MMH activities using a trolley. The research method used is the risk assessment of pushing and pulling (RAPP) tool and Nordic body map (NBM). The RAPP Tool consists of 9 assessments with a rating scale of good, reasonable, poor and unacceptable. Furthermore, using the NBM which mapped 28 body parts with a rating scale of no pain, moderately ill, sick and very sick.The results of the study contained 3 assessments of the RAPP Tool with the highest score, including floor surface, posture, and condition of the tool. The results of the NBM found that the body parts that often felt complaints were the back, waist, buttocks, left knee, right knee, left leg and right leg. The conclusion is that workers with high RAPP scores have an impact on high levels of muscle complaints so that improvements need to be made immediately to reduce ergonomic risks to workers.

Why multi-tier surgical instrument table matters? An ergonomic analysis from mento-physical demand perspectives

Using traditional back tables (BT) in operating rooms (OR) can lead to high physical/cognitive demand on nurses due to repetitive manual material handling activities. A multi-tier table (MTT) has been developed to relieve such stressors by providing extra working surfaces to avoid stacking the instrument trays and facilitate access to surgical tools. In this study, sixteen participants performed lifting/lowering and instrument findings tasks on each table, where kinematics, kinetics, subjective, and performance-related measures were recorded. Results indicated that MTT required lesser shoulder flexion (p-value<0.001), ∼14% lower shoulder loads (0.012), task completion time (<0.001), and cognitive/physical workloads (<0.004). Although peak low-back demands were ∼15% higher using MTT, the number of lifts to complete the same task was 60% lower, leading to lower cumulative demand on the low-back musculature. Utilizing MTT in OR could reduce demand and increase nurses' efficiency, leading to reduced risk of WMSDs and the total time of surgery.

Trunk Muscle Coactivation in People with and without Low Back Pain during Fatiguing Frequency-Dependent Lifting Activities

Lifting tasks are manual material-handling activities and are commonly associated with work-related low back disorders. Instrument-based assessment tools are used to quantitatively assess the biomechanical risk associated with lifting activities. This study aims at highlighting different motor strategies in people with and without low back pain (LBP) during fatiguing frequency-dependent lifting tasks by using parameters of muscle coactivation. A total of 15 healthy controls (HC) and eight people with LBP performed three lifting tasks with a progressively increasing lifting index (LI), each lasting 15 min. Bilaterally erector spinae longissimus (ESL) activity and rectus abdominis superior (RAS) were recorded using bipolar surface electromyography systems (sEMG), and the time-varying multi-muscle coactivation function (TMCf) was computed. The TMCf can significantly discriminate each pair of LI and it is higher in LBP than HC. Collectively, our findings suggest that it is possible to identify different motor strategies between people with and without LBP. The main finding shows that LBP, to counteract pain, coactivates the trunk muscles more than HC, thereby adopting a strategy that is stiffer and more fatiguing.

ANALISIS POSTUR KERJA MANUAL MATERIAL HANDLING (MMH) MENGGUNAKAN RAPID UPPER LIMB ASSESSMENT (RULA) DI PT.XYZ

The use of human labor in the industrial world in Indonesia is still very dominant, especially in Manual Material Handling (MMH) activities. The activity of bending and twisting in the workplace while doing MMH should be reduced or even if possible this activity should be eliminated because this attitude is prone to causing disorders of the musculoskeletal system. Considering that MMH activities have a vital role in the work carried out in the production process section, therefore the researcher will conduct an analysis of the Manual Material Handling (MMH) work posture using the Rapid Upper Limb Assessment (RULA). RULA is a work posture research method to investigate disorders of the upper limbs. The results of the work posture analysis based on the results of the assessment using the RULA method stated that all manual material handling activities assessed above required corrective action or efforts. In the shuttle area, the final score for the action category obtained is 7 with a high risk level and the action that must be taken is action now. In the Pirn Winder area, the final score for the action category obtained is 6 with a moderate risk level and the action that must be taken is action in the near future. In the vacuum heat setter area, the final score for the action category obtained is 7 with a high level of risk and the action that must be taken is action now.

Manufacturing Operator Ergonomics: A Conceptual Digital Twin Approach to Detect Biomechanical Fatigue

The primary sources of injuries in the workplace are improper manual material handling (MMH) motions, forklift collisions, slip, and fall. This research presents a Digital Twin (DT) framework to analyze fatigue in humans while performing lifting MMH activity in a laboratory environment for the purpose of reducing these types of injuries. The proposed methodology analyzes the worker’s body joints to detect biomechanical fatigue as a factor of change in back, elbow, and knee joint angles. Using the dynamic time warping (DTW) algorithm, the change in joint angles with time was analyzed. The variation in DTW parameters was evaluated using exponentially weighted moving average (EWMA) control charts for further analysis. A preliminary study considering two healthy male subjects performing seven experiments, each under an optical motion capture system was performed to test the model’s efficiency. Our contributions are twofold. First, we propose a model to detect biomechanical fatigue in the subjects performing MMH lifting activity as a change in joint angles. Secondly, the research also shows evidence that different individuals show signs of body fatigue via different body joints and showcases the need for a true personalized DT for an operator for fatigue assessment in an MMH environment.

Improved artificial neural networks for 3D body posture and lumbosacral moment predictions during manual material handling activities

Body posture measurement approaches, required in biomechanical models to assess risk of musculoskeletal injuries, are usually costly and/or impractical for use in real workplaces. Therefore, we recently developed three artificial neural networks (ANNs), based on measured posture data on several individuals, to predict whole body 3D posture (coordinates of 15 markers located on body’s main joints), segmental orientations (Euler angles of 14 body segments), and lumbosacral (L5-S1) moments during static manual material handling (MMH) activities (ANNPosture, ANNAngle, and ANNMoment, respectively). These ANNs require worker's body height, body weight (only for ANNMoment), hand-load 3D position, and its mass as inputs to accurately predict 3D marker coordinates (RMSE = 7.0 cm), segmental orientations (RMSE = 29.9°) and L5-S1 moments (RMSE = 16.5 N.m) for various static MMH activities. The current work aims to further improve the accuracy of these ANNs by performing outlier elimination and data normalization (as effective tools to improve the accuracy of ANNs) as well as by introducing participant’s knee flexion angle (i.e., lifting technique: stoop, semi-squat, and full-squat) and body weight as new inputs into these ANNs. Results indicate that the RMSE of the new ANNPosture, ANNAngle, and ANNMoment reduced by, respectively, ∼43%, 10%, and 29% (from 7.0 cm, 29.9°, and 16.5 Nm in the original ANNs to, respectively, 4.0 cm, 27.0°, and 11.8 Nm). Such significant improvements in the predictive power of our ANNs further confirm their effectiveness as alternative posture-prediction approaches requiring minimal in vivo data collection in real workplaces.

PENGARUH AKTIVITAS PENANGAN MATERIAL SECARA MANUAL PEKERJA TERHADAP KELUHAN MUSKULOSKELETAL : TINJAUAN SISTEMATIS

Manual material handling is an activity that provides easy load transfer in confined or irregular spaces. Based on the Global Burden of Disease (GBD) shows that around 1.71% billion people worldwide have musculoskeletal conditions. This study aims to analyze articles from journals in order to provide reliable information about the effect of manual material handling activities on workers' complaints of musculoskeletal disorders. This study uses a systematic review method by comparing the search results to the literature that has been obtained regarding manual material handling of workers for musculoskeletal complaints. The results obtained were 20 articles which were analyzed in a systematic review. Article published in Elsevier B.V, PubMed, Google Scholar. The inclusion criteria used were having full text, using English and Indonesian, having ISSN/ISBN, and being published in the last 7 years. While the exclusion criteria referred to are research articles that do not meet the sample, are irrelevant, do not comply with the provisions as a predetermined sample, the period of publication of the article before 2014, does not have the complete text, and does not have an ISSN or ISBN. All articles cover manual material handling activities that affect workers' musculoskeletal complaints. Manual material handling consists of pushing, pulling, lowering, lifting, and carrying objects. It can be concluded that proper manual material handling can improve the quality of life for workers.

Effects of Pause Design on the Decline in Pulling Effort and the Evaluation of Perceived Effort in Pulling Tasks

Pulling is one of the manual material handling activities that could lead to work-related musculoskeletal disorders. The objectives of this study were to explore the development of muscular fatigue when performing intermittent pulling tasks and to establish models to predict the pull strength decrease due to performing the tasks. A simulated truck pulling experiment was conducted. Eleven healthy male adults participated. The participants pulled a handle with a load of 40 kg, which resulted in a pulling force of approximately 123 N. The pulling tasks lasted for 9 or 12 min with one, two, or three pauses embedded. The total time period of the embedded pauses was 3 min. The pull strength after each pull and rest was measured. Ratings of the perceived exertion on body parts after each pull were also recorded. The results showed insignificant differences regarding the development of muscular fatigue related to rest frequency. We found that the development of muscular fatigue for pulling tasks with embedded pauses was significantly slower than that for continuous pulls. The forearm had a higher CR-10 score than the other body parts indicating that the forearm was the body part suffering early muscle fatigue. An exponential model was developed to predict the pull strength of the pulling tasks with embedded pauses. This model may be used to assess the developing of muscular fatigue for pulling tasks.

Keluhan Musculoskeletal Disorders dan Kelelahan Kerja pada Tenaga Kerja Bongkar Muat di Pelabuhan Tenau

Manual material handling activity is a job related to lifting, moving, pulling, and holding goods that rely on human labor, includes loading and unloading goods at the Labor of Tenau Kupang. This research aimed to know to determine the relationship between age, smoking habit, manual material handling activity, and temperature of the environment with complaints of musculoskeletal disorders and work fatigue of the labor at Tenau Kupang Harbour. The kind of research was a quantitative study with a cross-sectional approach. The Population of this research is 36 people. The taking of the sample was done by a total sampling method that is 36 people. The test used was the Chi-square test. The results of the research showed that 21 people (58,3%) suffer from musculoskeletal disorders and 19 people (52,8%) suffer from work fatigue. The results showed that as many as 29 people (80.6%) experienced MSDs complaints and as many as 25 people (69.4%) experienced work fatigue. The analysis showed that there was no relationship between age and smoking habits with MSDs complaints, while the risk level of MMH and ambient temperature had a relationship with MSDs complaints. There is no relationship between age, smoking habits, the level of risk of MMH with work fatigue, while ambient temperature has a significant relationship with work fatigue. Therefore, it is advisable for workers to stretch their muscles during breaks so as to reduce MSDs complaints. Meanwhile, the workers cooperative union needs to provide drinking water facilities in order to reduce worker dehydration.