Magister Scientiae - MSc / The aim of the study was to determine the prevalence of and risk factors contributing to work-related musculoskeletal injuries amongst underground mine workers in Kitwe, Zambia.

L'analyse ergonomique des postes de travail reste le point de départ de toute politique de prévention des risques de maladies professionnelles. De nombreux travaux scientifiques s'attachent à quantifier les déterminants à risque pour aboutir le plus souvent à un score de pénibilité. La difficulté actuelle des méthodes de cotation ergonomique se situe au niveau de la capture de ces déterminants. La majorité des systèmes se limitent à une collecte de données souvent subjective et très influencé par la personne effectuant la cotation. La volonté de l'entreprise par le biais de ce stage est d'objectiver l'analyse ergonomique des postes de travail par une capture du mouvement de l'opérateur. Le principale défi est le passage d'outil et de méthode scientifique à une utilisation de terrain avec toutes les contraintes qu'elle induit.L'apport des avancées technologiques et scientifiques encourage ce passage par des outils utilisable dans le contexte industriel. Les deux principaux objectif de ce stage se sont situer premièrement sur la limitation des biais de capture pour amener un précision et un standardisation de la mesure de terrain, ainsi que sur l'accès à de nouvelles données notamment l'aspect temporel de la tâche effectuée. Le matériel utilisé est le capteur de profondeur Kinect développé par Microsoft. Cet appareil fait l'objet d’études scientifique dans différents domaines et plus particulièrement dans son utilisation pour de la capture de mouvements.Lors de ce stage, nous nous somme attaché à traiter le signal émis par la Kinect, pour obtenir des données permettant le remplissage automatique de grille de cotation. Le bruit de mesure fût travailler à l'aide d'un filtre récursif passe bas utilisé fréquemment en laboratoire d'analyse du mouvement. Le traitement des données spatiales brut des articulations de l'opérateur pour obtenir des angles fit l'objet d'un grande partie du travail, car ne nombreux paramètre entre en jeu comme la position du capteur.La réussite du stage à permis de limiter la subjectivité de la mesure mais à également donnée l'accès à de nouveaux indices comme les pourcentage de temps de cycle passé à des angulations dangereuses pour l'opérateur. Le passage d'outil de laboratoire au terrain mérite encore d'être travaillé notamment dans la robustesse des systèmes développés et doit s'appuyer sur des expérimentations de laboratoire. / Evaluation of potential risks of musculoskeletal disorders in real workstations is challenging as the environment is cluttered, which makes it difficult to correctly and accurately assess the pose of a worker. Most of the traditional motion capture systems cannot deal with these workplace constraints. Being marker-free and calibration-free, Microsoft Kinect is a promising device to assess these poses, but the validity of the delivered kinematic data under work conditions is still unknown. In this thesis we first propose an extensive validation of the Kinect system in an ergonomic assessment context with sub-optimal capture condition. As most of the large inaccuracies come from occlusions, we propose a new example-based method to correct unreliable poses delivered by the Kinect in such a situation. We introduced the Filtered Pose Graph structure to make the method select the most relevant candidates before combination. In an ergonomics context, we computed RULA scores and compared them to those computed from an optoelectronic mocap system. We also propose to challenge our method in real workplace environment and compared its performance to experts' evaluation in the Faurecia company. Finally, we evaluated the relevance of the proposed method to estimate internal joint torques thanks to inverse dynamics, even if occlusions occur. Our method opens new perspectives to define new fatigue or solicitation indexes based on continuous measurement contrary to classical static images generally used in ergonomics. The computation time enables real-time feedback and interaction with the operator.

In this thesis, we summarize our empirical research as well as findings towards an implementation and perception of a live feedback posture correction tool. Our goal is to develop a tool that could help a sedentary user to maintain correct posture without having to evaluate by themselves if their sitting position is ergonomical. The focus of the thesis lies in the identification of a posture recognizing tool, how to make use of the posture recognizing tool to evaluate posture status, and how the user interface should be presented towards the user. We also, based on user experience, focus on the usability in terms of effectiveness, efficiency, satisfaction and user friendliness of said posture correction tool.We chose to evaluate how well 3 different posture detection algorithms would fit our implementation based upon a certain number of criteria. We used the algorithm to get joint position data and drew out vectors between every joint. With our vectors we could calculate the angles between limbs in the human body and by doing so, evaluate if the user has good or bad posture. We conducted experiments on 7 participants towards our system, 3 of them are UX experts and 4 of them had no previous experience in UX design, after each experiment we provided the participant with a survey to share their experiences. The survey was focused on usability and user experiences. We then drew an analysis from our empirical research to form a conclusion.We managed to create a fully functional prototype which accurately could determine the participants posture. Out of our 3 different posture detection algorithms, we selected Openpose. We used their unity plugin and were able to calculate angles between limbs with unity’s built in functions towards vectors. From our testing, we got a lot of useful critique towards how the tool waspresented and explained towards the user, most of the feedback was towards the guidelines of the camera setup and its lack of guidance in that phase. We also received very positive feedback towards the tool and functionality itself, how responsive and accurate the system was for example.We have concluded that even though the tool we developed has some faults from a user perspective, we have come a long way to create something innovative and interesting. If there would be more time and resources to be spent towards the tool, this tool could definitely become big in the ergonomic world.

Norden Machinery AB i Kalmar är idag en ledande leverantör inom högpresterande tubfyllingssystem. Dessa är mestadels automatiska, men när det gäller förpackning finns det några arbetsmoment som utförs manuellt. Detta gör att de ergonomiska aspekterna kring dessa arbetsmoment måste prioriteras högt. I den nuvarande situationen utgör panelarmen som håller fast maskinens kontrollpanel ett ergonomiskt problem då den varken går att höja eller sänka. Syftet med projektet är att tillsammans med Norden utveckla en ergonomisk och användarvänlig lösning gällande panelarmen vid tubfyllningsmaskinerna. Frågeställningen behandlar hur detta görs genom att integrera design för ergonomi, flexibilitet och moduläritet i designprocessen. För att uppfylla syftet och frågeställningen med arbetet användes den grundläggande produktutvecklingsprocessen som Ulrich och Eppinger (2012) har tagit fram. Processen utgår från en förstudie där kraven på produkten sammanställs i en kravspecifikation och att designproblemet delas upp i mindre delproblem. Med detta som grund genereras koncept som därefter utvärderas mot kravspecifikationen vilket slutligen resulterar i att ett koncept väljs ut för vidareutveckling. Till dessa steg har teori och verktyg kring ergonomi, flexibilitet och moduläritet implementerats. Den slutgiltiga lösningen utgörs av modulära komponenter och är betydligt mer ergonomisk och användarvänlig än Nordens nuvarande konstruktion. Lyftanordningen består av en parallellogram och en gasfjäder omslutna av ett par balkar. Detta ger den lyftfunktion som krävs för att konstruktionen ska kunna hålla skärmen på plats och dessutom erbjuda höj- och sänkbarhet. Båda fästena gjordes i princip identiska och baserades på fästena hos Nordens nuvarande lösning. På så sätt behöver inga nya fästpunkter konstrueras och kostnaden kan hållas nere. Överlag förväntas konstruktionen uppnå de förväntningar och mål som både vi och Norden har. Den ergonomiska designaspekten passade bäst in vid förstudien, vilket beror mycket på att teorin kring ergonomi har sin grund i de regler, riktlinjer och mål som berör slutprodukten. Moduläriteten bidrog till att mer detaljerade koncept kunde skapas tack vare problem-uppdelningen. Flexibiliteten var inte fullt lika användbar men gav bra understöd till moduläriteten under processens gång. Huvudsaken är att vid en implementering likt denna ta hänsyn till eventuella kompromisser som kan behöva göras, och att alltid ha slutmålet med projektet i åtanke. / Norden Machinery AB in Kalmar is today a leading supplier of high performance tubing systems. These are mostly automated, but in the case of packaging, there are some operations that are performed manually. This means that the ergonomic aspects of these operations must be given high priority. In the present situation, the panel arm that holds the machine's control panel constitutes an ergonomic problem as it cannot be raised or lowered. The purpose of the project is to develop an ergonomic and user-friendly solution for the panel arm at the tube filling machines together with Norden. The thesis question addresses how this is done by integrating design for ergonomics, flexibility and modularity in the design process. In order to fulfil the thesis question and the purpose of the work, the generic product development process developed by Ulrich and Eppinger (2012) was used. The process is based on a preliminary study where the needs and requirements of the product are compiled in a requirement specification, and where the design problem is divided into sub-problems. With this in mind, it is possible to generate concepts. These are then evaluated against the specification which results in a concept being chosen for further development. During this process, theory regarding ergonomics, flexibility and modularity have been implemented. The final solution consists of modular components and is considerably more ergonomic and user-friendly than Norden’s current design. The lifting device consists of a parallelogram and a gas spring enclosed by a pair of beams. This provides the lifting function required for the design to keep the screen in place and offer raising and lowering possibilities. The screen- and machine attachment were based on Norden’s current design. This means that there is no need to construct new attachment points and the cost can be kept down. Overall, the design is expected to achieve the expectations and goals that both we and Norden have. Design for ergonomics were best suited for implementation at the preliminary study, since it is based on the rules, guidelines and goals that concern the final product. Modularity contributed to the creation of more detailed concepts due to the sub-problems. Flexibility was not quite as useful but gave good support to modularity during the process. The main thing is to consider any compromises that may need to be made in an implementation like this, and to always have the final goal of the project in mind.

Although the level of automation in the automotive industry is currently high, real humans are still required for assembly tasks, for example, during overhead tasks. This type of work can cause injuries in workers in this sector, especially musculoskeletal disorders (MSDs), being a cause for the inability to work in developed countries and, in turn, becoming a significant health problem. There is an aim to reduce the risk for these type of injuries during the development processes of this type of assembly operations. Various options are currently being considered where technology and the human factor can be combined. Among them, we find the object of study for this project, an exoskeleton.The aim of this project is to study the biomechanical effects as well as the ergonomics of a passive exoskeleton called Paexo Shoulder, developed by the company Ottobock, with the aim of relieving tensions in the shoulder joints and upper part of the shoulders, during its use in assembly tasks. For this purpose, an experiment will be designed in which several participants will carry out a series of tasks both with and without the exoskeleton, in such a way that the effects of its use and how they affect the users of the product can be observed. For this purpose, an experiment was designed to evaluate the effects of the use or non-use of this exoskeleton on 10 participants when performing a task similar to an overhead task in an assembly line. For the evaluation of the product, the Xsens motion capture system, in particular the Awinda model, was used together with the ScaleFit software to evaluate the results obtained through the motion capture recordings. In addition, in order to improve Digital Human Modelling (DHM) tools, the same task was simulated with the IPS-IMMA software, where the results were later analysed and compared with the motion capture results through ScaleFit.The results showed relatively large improvements in the respective moment reduction at the shoulder joint when using the exoskeleton. However, it was also observed that due to the upward force exerted by the exoskeleton on the arms, participants spent less time in low-risk areas evaluated by ScaleFit and therefore, this effect needs to be studied further.

July 2010. "Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Occupational Therapy, Occupational Therapy Department, College of Allied Health and Nursing, Nova Southeastern University, Fort Lauderdale, Florida" Objective. The following research questions were posed: (1) Does participatory ergonomic education and programming influence occupational performance among cosmetologists? (2) Does ergonomic education and programming influence quality of life among cosmetologists? (3) Does ergonomic education and programming influence pain among cosmetologists? (4) Does ergonomic education and programming influence numbness and tingling in the upper extremities of cosmetologists? The purpose of this study was to: (1) implement a participatory ergonomic program for cosmetologists and (2) to examine the effectiveness of the implemented program in decreasing signs and symptoms associated with work-related musculoskeletal disorders. Method. A multiple baseline, single subject design was used. Data were collected from seven subjects for a total of 12 weeks. The intervention was introduced to subjects at different times throughout the study and consisted of general ergonomic education, a participatory ergonomic interview session, and basic range of motion stretches. Outcome measures included the QuickDASH, a 10-point pain scale, and a 10-point numbness and tingling scale. Data were analyzed using visual analysis techniques including the two-standard deviation band method and the binomial test method. Data trends were assessed to further support the results. Results. The results of this study indicate that ergonomic programming improved occupational performance, improved quality of life, decreased upper extremity pain, and decreased upper extremity numbness and tingling for several of the participants. The results of this study also produced statistically significant changes in QuickDASH scores indicating improved quality of life and improved occupational performance. Statistically significant change in pain scores and numbness/tingling scores indicated that several participants experienced decreased pain, numbness, and tingling in the upper extremity. Conclusion. The results of this study support the assumption that cosmetologists experience symptoms consistent with work-related musculoskeletal disorders and respond to participatory ergonomic programming similar to other working groups. The results of this study support the main principles of the participatory ergonomic approach which focus on involvement of the worker. The participatory ergonomic approach used in this study aligns with the client-centered principles found in the practice of occupational therapy and therefore provides evidence of effective occupational therapy intervention.

The use of Extended Reality(XR) technologies for training is gaining popularity, and flight training is one field that has begun experimenting with the best implementation for their needs. Both Virtual Reality (VR) and Mixed Reality (MR) have been used in flight simulators, but it is unclear which is the better fit. The research question is: Which implementation (VR, MR) fits better regarding psychological and ergonomic fidelity for flight training simulation? A fidelity/validity framework is used to measure and compare VR and MR in a prototype flight training simulation. Participants from the Swedish Air Force Combat Simulation Center (FLSC) with experience in extended reality (XR) and flight training simulations took part in the study. The results showed that participants performed better and reported a preference for mixed reality (MR) over virtual reality (VR), citing factors such as ease of adaptation, movements, and concentration. The thematic analysis identified three themes: naturalness, intuitiveness, and precision. Based on these findings, MR is deemed a better fit for flight training, offering a higher level of psychological and ergonomic fidelity than VR. This study can inform future research on XR and flight training simulations and inform the incorporation of XR technologies in the design of training simulations.

No description available.

<p>A model to predict carpal tunnel syndrome (CTS) risk would improve ergonomic assessments and help reduce the incidence of occupational CTS and its associated costs. Research spanning over sixty years has shown that deviated wrist, forearm, and hand posture has on the hydrostatic pressure within the carpal tunnel (also known as carpal tunnel pressure, CTP). Elevated CTP is a mechanism of the development, or aggravation of CTS symptoms. The purpose of this thesis was to develop a model to predict CTS risk, based on CTP, and incorporate the model into an ergonomic tool for use by ergonomists. An extensive literature review identified additional studies that investigated the effects of pronation/supination, finger posture, and fingertip loading on CTP. The effect of wrist, forearm, and hand posture was then incorporated into the model via a series of regression equations developed for each plane of movement. The effect of fingertip loading (independent to the posture effects) was included using a multiplier based on the hand posture and load magnitude. To provide a user-friendly tool for ergonomists, a graphical-user-interface was developed to predict CTS risk based on the developed model. Input variables were wrist, hand, and forearm posture, and fingertip loading. CTP program estimated CTP, and compared the predicted pressure to a known threshold beyond which median nerve function has been shown to degrade. The tool was then evaluated by comparing the output of the tool (CTS risk) to the incidence of CTS in a large automotive manufacturing environment. There was no significant difference between the two groups (workers completing jobs with an incidence of CTS and workers completing jobs with no incidence of CTS). The tool marks an important first step v towards providing ergonomists with a much-needed tool to predict CTS risk based on posture, frequency, and fingertip force.</p> / Master of Science (MSc)

Eine Digitalisierung des EAWS-Verfahrens kann bei der Identifikation ergonomischer Probleme und der Ableitung darauf aufbauender Maßnahmen unterstützen. Aktuelle EAWS-Digitalisierungen beschränken sich mehrheitlich auf die Darstellung von EAWS-Punkten und Belastungen. Um EAWS-Auswertungen bedarfsgerecht weiterzuent-wickeln, wurden mit Hilfe einer Online-Befragung der Bedarf und die Anforderungen an EAWS-Auswertungsfunktionen und Gestaltungs-elemente ermittelt. Hierzu wurden auch der EAWS-Nutzungskontext sowie die eingesetzten EAWS-Auswertungssysteme und deren Bewertung erhoben. Insgesamt nahmen 61 Personen u. a. aus den Bereichen Arbeits-planung, IE, Ergonomie, Gesundheitswesen und Management teil. Die Ergebnisse zeigen, für was das EAWS-Verfahren eingesetzt wird, welche Personen daran beteiligt sind, welche Systeme genutzt und welchen Auswertungsfunktionen ein besonderer Bedarf zugeordnet wird. Daraus lassen sich Schwerpunkte für die Weiterentwicklung von EAWS-Auswertungen ableiten.