Errors Using Observational Methods for Ergonomics Assessment in Real Practice

[EN] Objective: The degree in which practitioners use the observational methods for musculoskeletal disorder risks assessment correctly was evaluated. Background: Ergonomics assessment is a key issue for the prevention and reduction of work-related musculoskeletal disorders in workplaces. Observational assessment methods appear to be better matched to the needs of practitioners than direct measurement methods, and for this reason, they are the most widely used techniques in real work situations. Despite the simplicity of observational methods, those responsible for assessing risks using these techniques should have some experience and know-how in order to be able to use them correctly. Method: We analyzed 442 risk assessments of actual jobs carried out by 290 professionals from 20 countries to determine their reliability. Results: The results show that approximately 30% of the assessments performed by practitioners had errors. In 13% of the assessments, the errors were severe and completely invalidated the results of the evaluation. Conclusion: Despite the simplicity of observational method, approximately 1 out of 3 assessments conducted by practitioners in actual work situations do not adequately evaluate the level of potential musculoskeletal disorder risks. Application: This study reveals a problem that suggests greater effort is needed to ensure that practitioners possess better knowledge of the techniques used to assess work-related musculoskeletal disorder risks and that laws and regulations should be stricter as regards qualifications and skills required by professionals.This work was supported by the Programa estatal de investigacion, desarrollo e innovacion orientada a los retos de la sociedad of the government of Spain under Grant DPI2016-79042-R.Diego-Mas, JA.; Alcaide Marzal, J.; Poveda Bautista, R. (2017). Errors Using Observational Methods for Ergonomics Assessment in Real Practice. Human Factors The Journal of the Human Factors and Ergonomics Society. 59(8):1173-1187. https://doi.org/10.1177/00187208177234961173118759

An Overview of REBA Method Applications in the World

The objective of this work is to review literature, worldwide, in which the Rapid Entire Body Assessment (REBA) ergonomic assessment method was applied and count the number of times that REBA was applied together with other methods and subsequent incidence. The database used was the “Web of Science—Core Collection”. Only scientific articles and bibliographic reviews were included, analysing a total of 314 documents and selecting only 91. The use of the REBA method is indicated in terms of knowledge, country, year and journal sectors. It was most used in the knowledge areas of “Manufacturing” (24.18%), “Agriculture, forestry and fishing” (21.98%) and in “Other activities” (19.78%). One of the benefits of REBA is that it evaluates different body parts: upper limbs (arm, forearm and wrist), lower extremities, trunk and neck. It is a useful method to identify the forced postures adopted by workers to thus develop improvement measures if necessary. It is concluded that REBA method use has increased over the last decade, probably due to the digitization of knowledge. It is almost always applied in combination with other methods, and its use can be a positive indicator of company sustainability

Métodos ergonómicos observacionales para la evaluación del riesgo biomecánico asociado a desordenes musculoesqueléticos de miembros superiores en trabajadores 2014-2019

Introduction: Due to technological advances and the concern to improve the working conditions of the workers, observational evaluation methods (OEMs) have been used in studies during the years 2014 to 2019 for biomechanical risk assessment (BRA) associated witch musculoskeletal disorders (MSDs). However, the existence of new methods, as well as the frequency and form of used of those already recognized, is disseminated information and it is not easily accessible to professionals interested in this topic. This research seeks to compile what is reported on this topic, in order to facilitate what the reader wants and highlight the trends and gaps around the OEMs.Objective: To carry out a bibliographic review of scientific literature published between 2014 and 2019 where the use of OEMs for BRA from MSDs in upper limbs (UL) evidenced in workers.Methods: A search of articles was made in order to find the use of OEM, published in English in Medline, Science direct, and SCOPUS from 08/03/19 until 15/06/19.Results: Applying the exclusion and inclusion criteria, 41 articles were found in which ere, the use of eight OEMs associated with MSDs from UL with an increasing trend in publications during 2015 and 2018 were identified.Conclusion: OEMs continue to be highly reported, with few new methods found. The need for more publications in Colombia and Latin America is evident.Introducción: Debido a los avances en tecnología y a la preocupación por mejorar las condiciones laborales de los trabajadores, se han desarrollado métodos de evaluación observacionales (MEO) para la evaluación del riesgo biomecánico (ERB) asociado a desordenes musculoesqueléticos (DME), que han sido empleados en investigaciones publicadas durante los años 2014 - 2019. Sin embargo, la existencia de nuevos métodos, así como la frecuencia y forma de uso de los ya reconocidos, es una información que está diseminada y no es de fácil acceso para los profesionales interesados en el tema. Esta investigación busca compilar lo reportado sobre esta temática para facilitar su consulta y evidenciar las tendencias y vacíos en torno a los MEO.Objetivo: Realizar una revisión bibliográfica de la literatura científica publicada entre 2014-2019, donde se evidencie el uso de los MEO para ERB de DME en miembros superiores (MMSS) en trabajadores.Métodos: Se realizó una búsqueda de artículos que evidenciaran el uso de MEO, publicados en idioma inglés en Medline, ScienceDirect y Scopus desde el 08/03/19 hasta el 15/06/19.Resultados: Aplicados los criterios de inclusión y exclusión, se encontró el uso de ocho MEO para el estudio de DME de MMSS, de los cuales RULA, STRAIN INDEX, TLV for HAL y Check list OCRA, fueron los más reportados.Conclusión: Los MEO continúan siendo altamente reportados siendo pocos los nuevos métodos encontrados. Se evidencia la necesidad de mayores publicaciones en Colombia y América latina

Development of electromyography biofeedback device

Magistritöö Ergonoomika õppekavalElektromüograafia (EMG) on valdkond, mis on spetsialiseerunud elektrooniliste seadmete kasutamisele lihaste bioelektrilise aktiivsuse mõõtmiseks ja analüüsimiseks. Ergonoomikas kasutatakse lihasaktiivsuse mõõtmiseks mitteinvasiivset meetodit – pinnaelektromüograafiat (sEMG).Magistritöös uuriti Eesi maaülikoolis arendatava EMG tagasisideseadme edasiarenduse võimalusi, milleks viidi läbi mitmeetapiline patendiuuring ning uuriti seadme kasutusmugavust valjult mõtlemise meetodil. Patendiuuringust selgus, et EMG seadmete puhul kasutatakse peamiselt visuaalset, akustilist, taktiilset ning ka elektrilist tagasisidet. Arendatava seadme puhul kaaluti akustilise tagasiside lisamist. Samuti võib järeldada, et EMG-seadmetele on antud mitmeid patente, kuid ainult vähesed on saavutanud kommertsedu. Seega innovatsioon, mis võiks viia patenteerimiseni, seisneb pigem konstruktsioonielementide arendamises. Kasutajakogemuse uuringus tuvastati mitmed võimalikud seadme kasutamisest tulenevad vead ning esitati need parendusettepanekutena uue prototüübi disainimiseks.Electromyography (EMG) is a study specializing in the use of electronic devices to measure and analyse the bioelectric activity of muscles. In ergonomics a noninvasive method to measure muscle activity - surface electromyography (sEMG) is used. The Master's thesis examined the further development of the EMG feedback device developed at Estonian University of Life Sciences, for which a multi-stage patent study was carried out and the usability of the device was studied by means of Think Aloud Protocol. The patent study showed that in EMG devices mainly visual, acoustic, tactile and electrical feedback types are used. In the case of the device being developed, the addition of acoustic feedback was considered. It can also be concluded that numerous patents regarding EMG devices have been granted, but only few have been commercialised. and the innovative patentable solutions lie in developing particulate parts of the device. In the user experience study, several possible errors in the use of the device were identified and presented as suggestions for improvement to design a new prototype

Comparison of methods for ergonomic assessment of assembly operations

Magistritöö Ergonoomika õppekavalUurimistöö eesmärk oli koostada ajasäästlik ja koostetööde hindamiseks sobiv ülekoormuse riski hindamise protseduur, mille abil järjestada koostetööde ergonoomikaliste sekkumiste vajadus. Valdaval enamusel (94%) uuritava ettevõtte koosteoperaatoritel esines luu- ja lihaskonna vaevusi. Keha piirkonniti tõusis esile parem ülajäse, kuhu koondus ligikaudu viiendik kaebuste põhjal arvutatud valuskooride summast. Kuna vaevuste kaardistamine viitas täiendavat uurimist vajavale füüsilisele ülekoormusele ülajäsemes, siis valiti edasisteks hindamisteks meetodid, mis keskendusid ainult ülajäsemetele: HAL, Revised Strain Index, ART ja OCRA Checklist. Koostetööde hindamiseks filmiti kokku 10 töötajate poolt füüsiliselt raskeks või kergeks hinnatud koostetööd ning neid hinnati videosalvestiste põhjal eeltoodud meetoditega. Tulemuste analüüsist selgus, et kõige paremini ühtisid töötajate subjektiivsete hinnangutega meetodite HAL ja OCRA Checklist hindamistulemused. Meetodite omavahelises võrdluses vaadeldi koostetööde järjestust riskihinnete alusel. Ilmnes, et kõige tugevama seose (ρ = 0,90…0,93) ülejäänud meetoditega andis meetod HAL. Uurimistöö tulemustele tuginedes koostati uuritava ettevõtte jaoks füüsilise ülekoormuse riski hindamise protseduur, mis hõlmas esmalt töötajate subjektiivset hinnangut koostetöö raskusastmele, töötajate poolt füüsiliselt raskeks märgitud koostetööde esmast hindamist meetodiga HAL ning edasist hindamist vajavate toodete hindamine OCRA Checklistiga.The aim of this study was to develop a time-saving and suitable risk assessment procedure for assembly works by means of which the need for ergonomic intervention of assembly works could be ranked. The majority (94%) of the assembly operators of the studied company had musculoskeletal disorders. By body region, the upper limb accounted for about one-fifth of the sum of pain scores calculated from complaints. As the mapping of the disorders indicated physical overload in the upper limb, methods focusing only on the upper limbs were selected for further evaluations: HAL, Revised Strain Index, ART and OCRA Checklist. In order to evaluate the assembly works, a total of 10 assembly works assessed by the employees as physically difficult or light were video recorded and they were assessed on the basis of recordings using the above mentioned methods. The analysis of the results showed that the evaluation results of the HAL and OCRA Checklist methods matched the best with subjective evaluations of the employees. For the comparison of the methods the order of assembly works on the basis of risk evaluation scores were observed. It turned out that the strongest correlation (ρ = 0,90…0,93) with the other methods was given by the HAL method. Based on the results of the study, a procedure for assessing the risk of physical overload was developed for the company involved, which first included employees subjective assessment of the severity of the assembly work, an initial assessment of the assembly by the HAL method for the assembly works rated as physically difficult and further evaluation with OCRA Checklist if needed

The development of fully automated RULA assessment system based on Computer Vision

The purpose of this study was to develop an automated, RULA-based posture assessment system using a deep learning algorithm to estimate RULA scores, including scores for wrist posture, based on images of workplace postures. The proposed posture estimation system reported a mean absolute error (MAE) of 2.86 on the validation dataset obtained by randomly splitting 20% of the original training dataset before data augmentation. The results of the proposed system were compared with those of two experts’ manual evaluation by computing the Intraclass correlation coefficient (ICC), which yielded index values greater than 0.75, thereby confirming good agreement between manual raters and the proposed system. This system will reduce the time required for postural evaluation while producing highly reliable RULA scores that are consistent with those generated by manual approach. Thus, we expect that this study will aid ergonomic experts in conducting RULA-based surveys of occupational postures in workplace conditions

Madala maksumusega elektromüograafide rakendatavus ergonoomikalises hindamises

A thesis for applying for the degree of Doctor of Philosophy in Engineering Sciences.Every year a considerable amount of gross domestic product in several countries is lost due to work-related musculoskeletal disorders (WMSDs). Thus, one of the goals of ergonomics is to prevent WMSDs. A body of knowledge required to prevent WMSDs has existed for decades; however, the exploitation of this knowledge is hindered by the shortcomings in the risk assessment methods. As a rule, objective methods should be preferred to subjective methods, though often access to objective methods is restricted by the cost of the apparatus. The potential to make one of such devices more accessible by reducing the costs was investigated in the thesis. The thesis focused on the electromyograph – a device to study and monitor the electrical activity produced by skeletal muscles. Nowadays one can assemble an electromyograph from low-cost semi-universal components; however, the functionality and usability of such a device is unknown. At first the technical characteristics of components that can be used to assemble an electromyograph were evaluated. Then the electromyographs were assembled and tested in the laboratory and in the field. The results showed that the low-cost electromyographs may be partially utilised in ergonomic risk assessment; however, the use of such equipment in comparison to commercial high-cost apparatus increases the demands on user knowledge, skills and time expenditure. On the other hand, the functionality of the do-it-yourself electromyograph may exceed the commercial device.Tööga seotud luu- ja lihaskonna ülekoormushaiguste tõttu kaotavad riigid igal aastal märkimisväärse osa sisemajanduse kogutoodangust. Seetõttu on üheks ergonoomika eesmärgiks luu- ja lihaskonna ülekoormushaiguste ennetamine. Teadmised töötaja ülekoormuse ennetamiseks on olemas juba aastakümneid. Paraku takistavad teadmiste tõhusat rakendamist puudused riskihindamise meetodites. Riskide hindamisel tuleb subjektiivsetele meetoditele eelistada objektiivseid meetodeid, kuid sageli piirab objektiivsete meetodite kasutamist mõõteseadmete maksumus. Doktoritöös uuriti ühe sellist liiki mõõteseadme, lihaste elektrilise aktiivsuse uurimiseks mõeldud seireseadme ehk elektrimüograafi kättesaadavuse ja rakendamise suurendamise võimalust seadme maksumuse vähendamisega. Nüüdisajal on võimalus elektromüograafe kokku panna madala maksumusega ja pool-universaalsetest komponentidest. Samas pole selge, milline on sellisel viisil valmistatud elektromüograafi funktsionaalsus ja kasutatavus. Doktoritöös hinnati esmalt elektromüograafi madala maksumusega komponentide tehnilisi omadusi ning seejärel katsetati koostatud elektromüograafe laboris ja töökeskkonnas. Doktoritöö andis kinnitust, et madala maksumusega elektromüograafe on võimalik riskihindamisel osaliselt rakendada, kuid selliste seadmete kasutamine eeldab riskihindajalt põhjalikumaid teadmisi ja oskusi ning suuremat ajakulu kui kallite kommertsseadmete kasutamine. Samas võib spetsialisti kokkupandud elektromüograafi funktsionaalsus kommertsseadmeid ületada.Publication of this thesis is supported by the Estonian University of Life Sciences. This research was supported by European Regional Development Fund’s Doctoral Studies and Internationalisation Programme DoR

Aplicación del método REBA para mejorar la productividad laboral en el área de ventas de la empresa Atento, Ate 2021

En la presente investigación que lleva como título: “Aplicación del Método Reba para mejorar la productividad laboral en el área de ventas de la empresa Atento S.A.C., Ate 2021” el cual se tiene como objetivo: Determinar como la aplicación del método Reba mejora la productividad laboral en el área de ventas de la empresa Atento, Ate 2021. En el trabajo realizado se formulo una pregunta en base a la problemática que es ¿Cómo la aplicación del método Reba mejorará la productividad laboral en el área de ventas de la empresa Atento, Ate 2021? Esta investigación tiene como metodología utilizada es de diseño experimental: pre experimental de tipo aplicado, ya que esto determinará la mejora de la productividad laboral mediante la aplicación de aportes teóricos como lo es la utilización del Método Reba, para ello se utilizaron técnicas de recolección como el análisis documental e instrumentos como fichas de registros, se utilizó una de muestra de 10 trabajadores en un período de 26 días laborales. Con respecto a los resultados, estos muestran un incremento de 83.51% en la productividad laboral de los empleados del área de ventas del antes de aplicar la propuesta con un 42.56% y después de aplicar la propuesta de mejora con un 78.70%. Finalmente, se llego a la conclusión que el haber implementado el Método Reba para la mejora de la productividad laboral en el área de ventas de la empresa, obteniéndose así la relación de la eficacia y eficiencia, logrando una mejora significativa para el área de ventas en la empresa Atento S.A.C

XIII magistrantide teaduskonverents „Inimene ja tehnoloogiad“ : artiklite kogumik 

KonverentsikogumikEesti Maaülikooli Tehnikainstituudi XIII magistrantide teaduskonverentsi „Inimene ja tehnoloogiad“ [18. aprillil 2019] artiklite kogumik