Systematic Comparison of OWAS, RULA, and REBA Based on a Literature Review

This study aimed to systematically compare three representative observational methods for assessing musculoskeletal loadings and their association with musculoskeletal disorders (MSDs): Ovako Working Posture Analysis System (OWAS), Rapid Upper Limb Assessment (RULA), and Rapid Entire Body Assessment (REBA). The comparison was based on a literature review without time limitations and was conducted on various factors related to observational methods. The comparisons showed that although it has a significant limitation of comprising only two classifications for the leg postures, (1) the RULA is the most frequently used method among the three techniques; (2) many studies adopted the RULA even in evaluation of unstable lower limb postures; (3) the RULA assessed postural loads as higher risk levels in most studies reviewed in this research; (4) the intra- and inter-reliabilities for the RULA were not low; and (5) the risk levels assessed by the RULA were more significantly associated with postural load criteria such as discomfort, MHTs and % capable at the trunk, and MSDs.

APPLICATION OF HOUSE OF QUALITY IN THE CONCEPTUAL DESIGN OF BATIK WAX EXTRUDER AND PRINTER

Malaysian batik production is dominated by two techniques known as hand-drawn batik, or batik tjanting, and stamp batik, or batik block. In comparison to batik block, the more popular batik tjanting takes a longer time to produce. A Standardized Nordic Questionnaire (SNQ) for musculoskeletal symptom examination involving batik artisans in Kelantan and Terengganu identified high rates of musculoskeletal disorders in respondents due to their working posture during the batik tjanting process. It was also observed that the number of workers and artisans willing to participate in the traditional batik industry is on the decline. These problems have led to a systematic Quality Functional Deployment approach to facilitate the decision-making process for the conceptual design of an automatic batik printer. In this study, house of quality (HOQ) was applied to identify the critical features for a batik printer based on the voice of the customer (VOC). A survey done to rate the importance of VOC using an 8-point Likert scale revealed that the batik practitioners topmost priority for the batik printer feature is the 'ability to adjust and maintain the temperature of wax' (17.54%) while the non-batik practitioners chose 'ability to deliver a variety of complex designs' (15.94%). The least required feature for the batik printer was related to the size of the batik printer. The mapping between customer requirements (VOC) and technical requirements identified that the extruder design (21.3%), the heating element (18%), and nozzle diameter (17.8%) were the most critical components for the batik printer. Several conceptual designs of the extrusion unit, cartesian-based batik printer, and 2D image conversion using open-sourced software were proposed at the end of this work. ABSTRAK: Pengeluaran batik Malaysia telah didominasi oleh dua teknik yang dikenali sebagai batik lukisan-tangan (batik canting) dan batik cap (batik blok). Sebagai perbandingan, batik canting yang popular mengambil masa lebih lama bagi dihasilkan. Soal Selidik Nordic Standad (SNQ) bagi meneliti gejala muskuloskeletal melibatkan tukang batik di Kelantan dan Terengganu telah menunjukkan persamaan kadar muskuloskeletal yang tinggi pada postur badan semasa bekerja canting batik. Bilangan pekerja yang terlibat dalam industri tradisional batik ini turut terjejas. Masalah-masalah ini telah mengarah kepada kaedah Pengerahan Fungsi Kualiti bagi membantu proses membuat keputusan dalam rekaan konsep pencetak batik automatik. Kajian ini telah mengadaptasi Kualiti Rumah (HOQ) bagi mengesan ciri-ciri kritikal pada pencetak batik berdasarkan suara pelanggan (VOC). Kaji selidik telah dilakukan bagi menilai kepentingan VOC menggunakan skala Likert 8-poin. Didapati keutamaan yang diperlukan oleh 17.54% ahli batik adalah; ciri pencetak batik ini perlu mempunyai ‘keupayaan dalam menyelaras dan menetapkan suhu lilin’, manakala sebanyak 15.94% bukan ahli batik memilih ‘keupayaan pencetak ini harus berjaya menghasilkan pelbagai rekaan yang kompleks’. Ciri yang kurang diberi tumpuan adalah berkaitan saiz pencetak batik. Persamaan antara kehendak pelanggan (VOC) dan kehendak teknikal dalam mengenal pasti komponen-komponen penting bagi pencetak batik adalah rekaan penyemperit (21.3%), elemen pemanas (18%), dan diameter nozel (17.8%). Pelbagai rekaan konsep bagi unit penyemperit, pencetak batik canting, dan imej konversi 2D menggunakan perisian sumber terbuka telah dicadangkan di bahagian akhir kajian ini.

Methods of ensuring comfort and quality in the design of ecological and safe school furniture

Main problem: The functional state at the physiological, psychological and behavioral levels depends on the student's working posture and affects the fatigue and performance of schoolchildren. Each new development of school furniture will undergo several test cycles. None of these cycles can give a final version of the comfort and safety of the equipment. The evaluation of school furniture takes place in several directions: compliance with building regulations and standards in accordance with age and other physiological parameters, secondly, the quality, durability and strength of modern materials, as well as the design of the form of which will provide aesthetic needs and provide a number of functions that contribute to the development and correction of children during classes in various disciplines.That is why the main context of this article is the work on identifying an increase in the period of productive working capacity in children engaged in a new model of a school desk that meets the basic ergonomic requirements. Purpose: The purpose of this article is a hygienic assessment of the impact of the ergonomic parameters of the workplace, namely furniture, on the physiological, psychological and behavioral levels of the functional state of schoolchildren and the state of the musculoskeletal system. Methods:To achieve the scientific results of this study, the methods of information and analytical, professional graphic, ergonomic methods, modeling method, questionnaire and experiment were used. Results and their significance: In the process of analyzing the information, the material of scientific research was studied and classified, which substantiates the methods of analyzing the functional feasibility, environmental safety and constitutional justification of school furniture created on the basis of innovative technologies including special technical achievements that contribute to the improvement of students' performance, interest, passion and self-development. The author's classes and tables are proposed in which the data of questionnaires and typologies of various principles of artistic design are presented, contributing to the creation of unique and at the same time ergonomic and ecological and safe furniture for schools.

Peculiarities of the educational activity of higher education students in physical culture and sports during the use of distance forms of learning

In order to improve the educational process in the conditions of quarantine restrictions, it is important to assess the characteristics of students' reaction, depending on the specialty in which they receive education, to certain pedagogical methods and techniques characteristic of distance learning. The purpose of the work is to investigate the dynamics of students' attitude to distance learning and to identify the features of the educational process in the information and educational environment of higher education institutions depending on the field of study. The study from 2020 to 2021 involved 134 students of Kyiv National Economic University Vadym Hetman and 256 students of the National University of Physical Education and Sports of Ukraine. During the research such methods as analysis and generalization of literature sources, questionnaires, statistical analysis were used. Results. It was found that regardless of the direction of study, a decrease in motor activity in 2020 was noted by a statistically significant (p <0.05) larger share of freelance students than in 2021, which indicates the adaptation of participants in the educational process to distance learning and stabilization of their motor mode . It was found that students of economic education have a statistically significant (p <0.05) more time on the PC compared to those seeking higher education in physical education. In contrast to students of the Economic Free Economic Zone, the share of students of NUFVSU who mastered the theoretical knowledge of health at work at the computer, statistically significant (p <0.05) increased by 15.4%. In 2020, the shares of students who control the working posture of a PC user and perform mini-sets of exercises when working on a PC depending on the direction of study statistically significant (p> 0.05) did not differ, and in 2021 statistically significant (p <0.05) most students of NUFVSU remembered the need to maintain the ergonomically optimal posture of the PC user and performed such sets of physical exercises than among KNEU students. It was found that among the students of NUFVSU statistically significant (p <0.05) a larger proportion is systematically engaged in health-improving motor activity and cares about health while working on the PC compared to students of KNEU. Also statistically significant (p <0.05), a higher percentage of NUFVSU students indicate the absence of discomfort in the spine after prolonged work on the PC.

Recognition of Manual Welding Positions from Depth Hole Image Remotely Sensed by RGB-D Camera

The proportion of welding work in total man-hours required for shipbuilding processes has been perceived to be significant, and welding man-hours are greatly affected by working posture. Continuous research has been conducted to identify the posture in welding by utilizing the relationship between man-hours and working posture. However, the results that reflect the effect of the welding posture on man-hours are not available. Although studies on posture recognition based on depth image analysis are being positively reviewed, welding operation has difficulties in image interpretation because an external obstacle caused by arcs exists. Therefore, any obstacle element must be removed in advance. This study proposes a method to acquire work postures using a low-cost RGB-D camera and recognize the welding position through image analysis. It removes obstacles that appear as depth holes in the depth image and restores the removed part to the desired state. The welder’s body joints are extracted, and a convolution neural network is used to determine the corresponding welding position. The restored image showed significantly improved recognition accuracy. The proposed method acquires, analyzes, and automates the recognition of welding positions in real-time. It can be applied to all areas where image interpretation is difficult due to obstacles.

Physical Welding Factors for Reclassified Welding Positions in Shipbuilding Assembly Process Based on Muscle Activity Measured by Surface Electromyography

Welding, a key technology in the shipbuilding industry, is mostly performed by hand, owing to the complex structure and shape of production blocks. This manual welding requires a variety of working postures, which have become an important determinant of the worker’s workload and, consequently, assembly man-hours. Currently, major shipyards calculate welding man-hours by reflecting the welding factor, which is defined as the working time consumed in the welding process. A set of welding factors is known to be based on the accumulated experience in shipyards, whereas the verification or derivation process for these factors is not disclosed or available. This study proposed a method for quantitatively calculating work difficulty for welding positions based on the working posture in a process where the posture acts as an important variable. Standard welding positions reflecting the actual welding work at shipyards were established. A physiological assessment method was used to propose the physical welding factor by analyzing the measured muscle activity. The validity of the proposed method was verified by comparing the results of a musculoskeletal simulation package and shipyard welding factors. The proposed method can be readily applied to other fields in which workers’ physical activities are involved.

Perbaikan Tingkat Risiko Musculoskeletal Disorders Berdasarkan Pendekatan Nordic Body Map dan Rapid Upper Limb Assessment Pada Hasil Rancang Bangun Mesin Roasting Kopi Digital Otomatis

The roasting process of coffee beans in West Kalimantan, especially Pontianak city, is still done traditionally. The coffee roasting process is done manually by using a fire stove as a heater. Workers with standing posture stir the coffee beans continuously, and it can take 4 hours for 20 kilos of coffee beans. Standing work posture is required for stirring the coffee beans but can cause fatigue in workers due to long-standing times and high heating temperatures. This situation causes the roasting process to be less efficient and can cause the roasting process to be uneven. The purpose of this study was to identify musculoskeletal complaints of standing work posture in the manual coffee roasting process and provide an evaluation of corrective work posture when using the design results of an automatic digital roasting machine. The methods used in this study were the Nordic Body Map (NBM) and the Rapid Upper Limb Assessment (RULA) to assess the level of risk of posture for musculoskeletal complaints. The results of the identification of body points that experience fatigue were carried out by distributing NBM questionnaires and evaluating the worker's posture using RULA on CATIA V5R20. Based on the existing NBM, the risk score is 78, and the final RULA score is 6, which means that immediate corrective action is needed because the work posture is categorized as dangerous and does not meet ergonomic principles. Improvement of working posture is made by designing a roasting machine that is digital and automatic. So the workers do not need to mix the coffee beans manually. Based on roasting machine implementation results, there was a significant change in the NBM score and the final RULA score. The NBM results obtained a score of 55 which means that the risk is moderate with the risk of fatigue in the neck, right leg and, left leg. Meanwhile, evaluation of work posture based on RULA on CATIA obtained a final score of 3, which means that the work posture is not dangerous and does not require immediate improvement.

Ergonomic Comparison of Four Dental Workplace Concepts Using Inertial Motion Capture for Dentists and Dental Assistants

When the inventory is arranged in a dental practice, a distinction can be made between four different dental workplace concepts (DWCs). Since the prevalence of musculoskeletal diseases in dental professionals is very high, preventive solution need to be investigated. As the conventionally used DWCs have, to date, never been studied in terms of their ergonomics, this study aims to investigate the ergonomic risk when working at the four different DWCs. In total, 75 dentists (37 m/38 f) and 75 dental assistants (16 m/59 f) volunteered to take part in this study. Standardized cooperative working procedures were carried out in a laboratory setting and kinematic data were recorded using an inertial motion capture system. The data were applied to an automated version of the Rapid Upper Limb Assessment (RULA). Comparisons between the DWCs and between the dentists and dental assistants were calculated. In all four DWCs, both dentists and dental assistants spent 95–97% of their working time in the worst possible RULA score. In the trunk, DWCs 1 and 2 were slightly favorable for both dentists and dental assistants, while for the neck, DWC 4 showed a lower risk score for dentists. The ergonomic risk was extremely high in all four DWCs, while only slight advantages for distinct body parts were found. The working posture seemed to be determined by the task itself rather than by the different inventory arrangements.

PENGURANGAN RISIKO MUSCULOSKELETAL DISORDERS PADA AREA MESIN LASER PERFORATOR DI PERUSAHAAN ROKOK MENGGUNAKAN OWAS DAN QFD

Di dalam perusahaan produksi rokok ini terdapat sebuah mesin laser perforator. Setelah pemasangan mesin laser perforator 50 timbul masalah yang berhubungan dengan gangguan muskuloskeletal. Saat dilakukan wawancara, operator mengeluhkan adanya nyeri punggung bawah karena penanganan material dilakukan secara manual. Setelah dilakukan analisis dengan metode OWAS pada dua kegiatan bongkar muat ditemukan masalah yang berhubungan dengan gangguan muskuloskeletal. Dari hasil analisis ditemukan bahwa aktivitas pemuatan (loading) dikategorikan sebagai tindakan korektif 3 artinya postur tubuh berpengaruh sangat merugikan pada sistem muskuloskeletal, sedangkan kegiatan pembongkaran (unloading) termasuk tindakan korektif 2 yang tidak berpengaruh nyata terhadap sistem muskuloskeletal. Selain itu, analisis gaya tekan dilakukan hanya untuk aktivitas pembebanan terhadap gaya tekan total yang bekerja pada L5/ S1. Gaya tekan untuk aktivitas pembebanan adalah 7.186,22 Newton atau lebih dari dua kali lipat dari batas aman maksimum 3.400 Newton. Perbaikan dilakukan dengan menggunakan metode QFD. Sebagai solusinya adalah dibuat troli. Troli tersebut mampu mereduksi gaya tekan total pada aktivitas pembebanan menjadi 3.180,52 Newton dan berhasil mengubah menjadi kategori tindakan korektif 1. Abstract[REDUCTION OF MUSCULOSCELETAL DISORDERS RISK ON LASER PERFORATOR MACHINES AREA IN CIGARETTE COMPANIES USING QFD AND OWAS] Inside this cigarette production company, there is a laser perforator machine. After the installation of the laser perforator machine 50, problems related to musculoskeletal disorders arise. During the interview, the operator complained about low back pain due to manual handling of the material. After analyzing the OWAS method on two loading and unloading activities, problems were found related to musculoskeletal disorders. It was found that the loading activity was categorized as 3 meaning that posture had a very detrimental effect on the musculoskeletal system. Meanwhile, unloading activities included category 2 which had no significant effect on the musculoskeletal system. In addition, the biomechanical analysis was carried out only for the loading activity against the total compressive force acting on L5 / S1. The compressive force for loading activity is 7,186.22 Newton or more than twice the maximum safe limit of 3,400 Newton. Repairs were made using the QFD method. The solution is to make the moving trolley. The moving trolley is able to reduce the total compressive force on the loading activity to 3,180.52 Newton and also, reduce the level to category 1.Keywords: biomechanics; musculoskeletal disorders; Ovako Working Posture Analysis System; OWAS; Quality Function Deployment; QFD; Trolley

KESAN MENGOKOK KEPADA POSTUR ERGONOMICS: KAJIAN KES PENGOKOK ETAK WARISAN DI KELANTAN, MALAYSIA

AbstrakKajian ini membincangkan tentang kesan aktiviti mengokok dalam kalangan pengokok etak yang terdapat di Kelantan. Masalah gangguan otot Muscular telah dikenalpasti wujud dalam kalangan responden yang dikenali sebagai Musculoskeletal disorder (MSD), kesan daripada menggunakan peralatan “mengokok” yang diwarisi turun-temurun. Masalah seperti kelenguhan, kesakitan dan ketidakselesaan pada bahagian otot responden semasa aktiviti “mengokok” etak menjadi permasalahan utama bagi kajian ini. Kajian ini melibatkan tiga responden yang merupakan antara pengokok etak yang masih bergiat aktif di Kelantan. Kajian menggunakan metod temubual, pemerhatian dan thematic analysis untuk menganalisis dapatan kajian. Dapatan kajian menunjukkan bahagian badan yang terjejas secara langsung akibat aktiviti “mengokok” dalam jangka masa yang panjang ialah pada bahagian tulang belakang (back spine) dan pergelangan tangan. Antara faktor-faktor yang menyumbangkan hazard adalah peralatan “mengokok” yang digunakan oleh responden. Hasil temubual menunjukkan, faktor postur memainkan peranan penting dalam hubungkait antara MSD dan masalah-masalah kesihatan yang dialami oleh responden. AbstractThis study discusses the effects of etak harvesting activities among etak harvester found in Kelantan. Muscular Muscle Disorders is identified to exist among respondents as the effects of using harvester equipment for a prolonged time. Few difficulties have been identified such as lethargy, pain and discomfort in the muscles of the respondents during the activity of harvesting etak. This study involved three respondents who are among the etak harvester that are still active in Kelantan. The study adopted ethnographic approaches which are interviewmethods, observations, and Nordic Body Map analysis to analyze the findings of the study. The findings of the study show that the parts of the body that are affected by the prolonged harvesting activities are the back spine and wrists. Among the factors that contributed to the hazard was the harvesting equipment used by the respondents. The results of the interviews showed that working posture plays an important role in probing the relationship between MSD and health problems experienced by the respondents.