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oai:recercat.cat:2117/1664452025-07-22T15:43:54Zcom_2072_1033col_2072_452951

Functional biomechanical evaluation of industrial lower limb exoskeletons based on electromyography Danús Jaume, Joan Universitat Politècnica de Catalunya. Departament d'Enginyeria Mecànica Font Llagunes, Josep Maria Àrees temàtiques de la UPC::Economia i organització d'empreses::Gestió i direcció::Ergonomia Human engineering Ergonomics Ergonomia The problem of bad ergonomic conditions in the day-to-day workplace has been always present and source of controversy in automotive industry, with matters such as musculoskeletal injuries and absenteeism that have been concerning companies from this sector. Nevertheless, in recent years exoskeletons have emerged as one of the most promising solutions. Hence, the aim of this project is to evaluate, in terms of electromyography (EMG), how the introduction of exoskeletons can affect to automotive industry workers labor. This means extracting muscular activity information when operating with and without the exoskeleton and find out if there exist any important differences. In order to better understand the context of this project, other approaches are presented and information about electromyography detection is introduced as well. In particular, a worker from company Meleghy Automotive Barcelona S.A.U. has been the one studied and tests have been performed at her normal workplace. Moreover, exoskeleton used for the project is the prototype LegX from SuitX, and most important muscles that have been explored are semitendinosus, biceps femoris, vastus medialis, vastus lateralis, rectus femoris, gastrocnemius medialis, tibialis anterior and erector spinae lumbar, with other complementary muscles from the upper body. As part of the protocol, maximum voluntary contraction (MVC) exercises were performed to the worker in order to extract valuable variables such as maximum 50% of the EMG signal (Percent50) and maximum 10% of the signal (Percent10). Those exercises implied displaying the maximum force capable to perform for each muscle studied, so then results for EMG signal can be normalized with respect to that maximum for an easier comprehension. In addition, EMG root mean square (RMS) has been another important metric for obtaining absolute values. Finally, a frequential analysis was performed, extracting the mean power frequency (MPF) of the signal which gives information about muscle fatigue. Regarding obtained results, promising values have been obtained for hamstrings (biceps femoris and semitendinosus), gastrocnemius, tibialis anterior and upper body muscles, reaching in some cases activations up to 20-30% lower when wearing the exoskeleton. However, some limitations have been found to the tests, being the poor training with the exo the most important one. Finally, as a conclusion from answers given to a questionnaire performed by the worker, improvements in the exoskeleton prototype should be studied in order to make it more comfortable, lighter and adapted to the user requirements. 2019-07-10 Master thesis https://hdl.handle.net/2117/166445 ETSEIB-240.145387 eng Restricted access - author's decision application/pdf Universitat Politècnica de Catalunya