31. Passive shoulder exoskeletons : more effective in the lab than in the field?Sander De Bock, Jo Ghillebert, Renée Govaerts, Shirley A. Elprama, Uroš Marušič, Ben Serrien, An Jacobs, Joost Geeroms, Romain Meeusen, Kevin De Pauw, 2021, izvirni znanstveni članek Povzetek: Shoulder exoskeletons potentially reduce overuse injuries in industrial settings including overhead work or lifting tasks. Previous studies evaluated these devices primarily in laboratory setting, but evidence of their effectiveness outside the lab is lacking. The present study aimed to evaluate the effectiveness of two passive shoulder exoskeletons and explore the transfer of laboratory-based results to the field. Four industrial workers performed controlled and in-field evaluations without and with two exoskeletons, ShoulderX and Skelex in a randomized order. The exoskeletons decreased upper trapezius activity (up to 46%) and heart rate in isolated tasks. In the field, the effects of both exoskeletons were less prominent (up to 26% upper trapezius activity reduction) while lifting windscreens weighing 13.1 and 17.0 kg. ShoulderX received high discomfort scores in the shoulder region and usability of both exoskeletons was moderate. Overall, both exoskeletons positively affected the isolated tasks, but in the field the support of both exoskeletons was limited. Skelex, which performed worse in the isolated tasks compared to ShoulderX, seemed to provide the most support during the in-field situations. Exoskeleton interface improvements are required to improve comfort and usability. Laboratory-based evaluations of exoskeletons should be interpreted with caution, since the effect of an exoskeleton is task specific and not all infield situations with high-level lifting will equally benefit from the use of an exoskeleton. Before considering passive exoskeleton implementation, we recommend analyzing joint angles in the field, because the support is inherently dependent on these angles, and to perform in-field pilot tests. This paper is the first thorough evaluation of two shoulder exoskeletons in a controlled and infield situation.
Ključne besede: assistive devices, exoskeletons, ergonomics, industrial plants, system validation
Objavljeno v DiRROS: 28.02.2022; Ogledov: 781; Prenosov: 563
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32. Lower-limb muscle contractile properties, explosive power and the subjective response of elite soccer players to the Covid-19 lockdownArmin Paravlić, Boštjan Šimunič, Saša Pišot, Matej Kleva, Kaja Teraž, Matjaž Vogrin, Uroš Marušič, Rado Pišot, 2022, izvirni znanstveni članek Povzetek: The present study examined the effects of the lockdown period on basic anthropometric measures, countermovement jumping performance, skeletal muscle contractile properties derived from tensiomyography (TMG), injury incidence, and self-assessed general well-being in elite soccer players. A total of 266 players were assessed before (PRE) and 32 players were reassessed 11 days after (POST) the COVID-19 period. Significant changes in the TMG parameters were observed POST compared to PRE: contraction time (Tc) increased from 6% to 50% in vastus lateralis [VL] (p = 0.009) and biceps femoris [BF] (p < 0.001), respectively; whereas radial displacement (Dm) increased for 19% in BF (p = 0.036) and 17% in VL (p < 0.001), respectively. Jumping performance remained unchanged from PRE to POST In addition, athletes rated the lockdown period as a positive event and felt psychologically better during the lockdown, primarily because they spent more time with family members and friends. Although there were no differences in any of the variables describing lower limb muscle power following the two-month lockdown, the altered contractile properties of the assessed muscles suggest suboptimal conditioning of the football players.
Ključne besede: football, male football, power, explosive power, tensiomyography, coronavirus, covid-19, pandemics, lockdown
Objavljeno v DiRROS: 06.01.2022; Ogledov: 912; Prenosov: 545
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34. Možganski marker senzomotorične učinkovitosti za optimizacijo športnih dosežkov pri igrah z loparji : končno poročilo o rezultatih raziskaveLuka Šlosar, Uroš Marušič, Boštjan Šimunič, Rado Pišot, 2021, končno poročilo o rezultatih raziskav Ključne besede: šport, športne igre, tenis, namizni tenis, badminton, športni dosežki, senzomotorična učinkovitost, možganski markerji
Objavljeno v DiRROS: 17.12.2021; Ogledov: 958; Prenosov: 297
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36. Stand up to excite the spine : neuromuscular, autonomic, and cardiometabolic responses during motor imagery in standing vs. sitting postureSidney Grosprêtre, Uroš Marušič, Philippe Gimenez, Gael Ennequin, Laurent Mourot, Laurie Isacco, 2021, izvirni znanstveni članek Povzetek: Motor imagery (MI) for health and performance strategies has gained interest in recent decades. Nevertheless, there are still no studies that have comprehensively investigated the physiological responses during MI, and no one questions the influence of low-level contraction on these responses. Thus, the aim of the present study was to investigate the neuromuscular, autonomic nervous system (ANS), and cardiometabolic changes associated with an acute bout of MI practice in sitting and standing condition. Twelve young healthy males (26.3 % 4.4 years) participated in two experimental sessions (control vs. MI) consisting of two postural conditions (sitting vs. standing). ANS, hemodynamic and respiratory parameters, body sway parameters, and electromyography activity were continuously recorded, while neuromuscular parameters were recorded on the right triceps surae muscles before and after performing the postural conditions. While MI showed no effect on ANS, the standing posture increased the indices of sympathetic system activity and decreased those of the parasympathetic system (p < 0.05). Moreover, MI during standing induced greater spinal excitability compared to sitting posture (p < 0.05), which was accompanied with greater oxygen consumption, energy expenditure, ventilation, and lower cardiac output (p < 0.05). Asking individuals to perform MI of an isometric contraction while standing allows them to mentally focus on the motor command, not challenge balance, and produce specific cardiometabolic responses. Therefore, these results provide further evidence of posture and MI-related modulation of spinal excitability with additional autonomic and cardiometabolic responses in healthy young men.
Ključne besede: heart rate, oxygen uptake, VO2, H-reflex, elektromyography
Objavljeno v DiRROS: 29.11.2021; Ogledov: 906; Prenosov: 867
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37. Dual-task performance in hearing-impaired older adults : study protocol for a cross-sectional mobile brain/body imaging studyAnna Wunderlich, Oliver Vogel, Maja Maša Šömen, Manca Peskar, Madeleine Fricke, Klaus Gramann, Janna Protzak, Uroš Marušič, Bettina Wollesen, 2021, izvirni znanstveni članek Povzetek: Background: Hearing impairments are associated with reduced walking performance under Dual-task (DT) conditions. Little is known about the neural representation of DT performance while walking in this target group compared to healthy controls or younger adults. Therefore, utilizing the Mobile Brain/Body Imaging approach (MoBI), we aim at gaining deeper insights into the brain dynamics underlying the interaction of cognitive and motor processes during different DT conditions (visual and auditory) controlling for age and the potential performance decrements of older adults with hearing impairments. Methods: The cross-sectional study integrates a multifactorial mixed-measure design. Between-subject factors grouping the sample will be age (younger vs. older adults) and hearing impairment (mild vs. not hearing impaired). The within-subject factors will be the task complexity (single- vs. DT) and cognitive task modality (visual vs. auditory). Stimuli of the cognitive task will vary according to the stimulus modality (visual vs. auditory), presentation side (left vs. right), and presentation-response compatibility (ipsilateral vs. contralateral). Analyses of DT costs and underlying neuronal correlates focus either on gait or cognitive performance. Based on an a priori sample size calculation 96 (48 healthy and 48 mildly hearing impaired) community-dwelling older adults (50%70 years) and 48 younger adults (20%30 years) will be recruited. Gait parameters of speed and rhythm will be captured. EEG activity will be recorded using 64 active electrodes. Discussion: The study evaluates cognitive-motor interference (CMI) in groups of young and older adults as well as older adults with hearing impairment. The underlying processes of the interaction between motor and cognitive tasks will be identified at a behavioral and neurophysiological level comparing an auditory or a visual secondary task. We assume that performance differences are linked to different cognitive-motor processes, i.e., stimulus input, resource allocation, and movement execution. Moreover, for the different DT conditions (auditory vs. visual) we assume performance decrements within the auditory condition, especially for older, hearing-impaired adults. Findings will provide evidence of general mechanisms of CMI (ST vs. DT walking) as well as task-specific effects in dual-task performance while over ground walking.
Ključne besede: older adults, overground walking, dual-tasks, MoBi, hearing impairments
Objavljeno v DiRROS: 23.11.2021; Ogledov: 827; Prenosov: 863
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38. Reduced parasympathetic reactivation during recovery from exercise in myalgic encephalomyelitis/chronic fatigue syndromeJessica Van Oosterwijck, Uroš Marušič, Inge De Wandele, Mira Meeus, Lorna Paul, Luc Lambrecht, Greta Moorkens, Lieven Danneels, Jo Nijs, 2021, izvirni znanstveni članek Povzetek: Although autonomic nervous system (ANS) dysfunction in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) has been proposed, conflicting evidence makes it difficult to draw firm conclusions regarding ANS activity at rest in ME/CFS patients. Although severe exercise intolerance is one of the core features of ME/CFS, little attempts have been made to study ANS responses to physical exercise. Therefore, impairments in ANS activation at rest and following exercise were examined using a case-control study in 20 ME/CFS patients and 20 healthy people. Different autonomous variables, including cardiac, respiratory, and electrodermal responses were assessed at rest and following an acute exercise bout. At rest, parameters in the time-domain represented normal autonomic function in ME/CFS, while frequency-domain parameters indicated the possible presence of diminished (para)sympathetic activation. Reduced parasympathetic reactivation during recovery from exercise was observed in ME/CFS. This is the first study showing reduced parasympathetic reactivation during recovery from physical exercise in ME/CFS. Delayed HR recovery and/or a reduced HRV as seen in ME/CFS have been associated with poor disease prognosis, high risk for adverse cardiac events, and morbidity in other pathologies, implying that future studies should examine whether this is also the case in ME/CFS and how to safely improve HR recovery in this population.
Ključne besede: autonomic nervous system, autonomic function, electrodermal activity, electrocardiogram, heart rate, physical activity
Objavljeno v DiRROS: 20.10.2021; Ogledov: 979; Prenosov: 851
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39. Učinkovitost računalniškega kognitivnega treninga v domovih starejših občanovUroš Marušič, Zdenka Milič Žepič, Voyko Kavcic, 2021, izvirni znanstveni članek Povzetek: Ohranjanje in krepitev fi zičnega in kognitivnega zdravja je pri starejših osebah izziv, še posebej pri tistih, ki so podvržene pospešenim starostnim ali nevrodegenerativnim spremembam. Obstoječe nefarmakološke intervencije lahko stabilizirajo ali upočasnijo kognitivni upad, vendar se učinkovite preventivne tretmaje, ki bi zakasnili pojavnost simptomov, še raziskuje. Eden izmed nefarmakoloških tretmajev je kognitivni trening. Namen naše raziskave je bil oceniti izvedljivost in učinkovitost kognitivnega treninga z nalogo prostorske navigacije pri stanovalcih domov starejših občanov. Enaintrideset stanovalcev (povprečna starost 81,6 leta, razpon 69%94 let; povprečna ocena MoCA 22,8 točke, razpon 17%27; 7 moških) je bilo naključno razporejenih v kontrolno skupino ali intervencijsko skupino. Slednja je bila vključena v dvomesečni kognitivni trening (2-krat tedensko; skupaj 16 treningov), v katerem so udeleženci vadili učenje virtualnega labirinta. Vsi udeleženci raziskave so bili merjeni pred in po intervenciji na nevropsihološki ocenjevalni bateriji testov. Udeleženci kontrolne skupine niso prejeli nobene posebne obravnave in so tako sodelovali le na %pred in po% meritvah. Pomembne izboljšave so bile ugotovljene le pri Reyjevem testu slušno-besednega učenja (AVLT), kjer so udeleženci v intervencijski skupini značilno izboljšali svoj rezultat v primerjavi s kontrolno skupino. Kljub omejeni učinkovitosti kognitivnega treninga je bila naša intervencija izvedljiva in pozitivno sprejeta s strani večine udeležencev. Nadaljnje raziskave bi morale ovrednotiti dolgoročne učinke kognitivnega treninga na druge funkcionalne sposobnosti in aktivnosti vsakodnevnega življenja. Na splošno naša raziskava ponuja empirične dokaze, da je kognitivni trening sprejemljiv za stanovalce domov za starejše občane, in kar je najpomembneje, da lahko izboljša mnemonične kognitivne sposobnosti.
Ključne besede: staranje, kognitivni trening, prostorska navigacija, naloge, virtualni labirint, domovi za starejše občane
Objavljeno v DiRROS: 13.05.2021; Ogledov: 1229; Prenosov: 1031
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40. Higher neural demands on stimulus processing after prolonged hospitalization can be mitigated by a cognitively stimulating environmentUroš Marušič, Rado Pišot, Voyko Kavcic, 2021, izvirni znanstveni članek Povzetek: Prolonge d periods of complete physical inactivity or bed rest trigger various alterations in the functional and metabolic levels of the human body. However, bed rest-related adaptations of the central nervous system are less known and thoroughly studied. The aim of this study was to investigate brain electrophysiological changes using event-related potentials (ERPs) after 14 days of bed rest and 12 consecutive sessions of computerized cognitive training (CCT). Sixteen older (Mage= 60 years) healthy volunteers were randomly divided into a CCT treatment group and an active control group. All participants performed ERP measurements based on the foveal visual presentation of a circle on a black background before and after bed rest. After 14 days of bed rest, participants in the control group showed increased peak P1 amplitude (p = .012), decreased P1 latency (p = .024), and increased P2 amplitude (p = .036), while the CCT group also showed decreased P1 latency (p = .023) and decreased P2 latency (p = .049). Our results suggest that, even from a central adaptation perspective, prolonged periods of physical inactivity or bed rest trigger additional neural recruitment and should therefore be minimized, and that CCT may serve as a tool to mitigate this. Future research should focus on other aspects of central nervous system adaptation following periods of immobilization/hospitalization to improve our knowledge of infl uence of physical inactivity and its eff ects on cortical activity and to develop appropriate countermeasures to mitigate functional dysregulation.
Ključne besede: aging, physical inactivity, immobilization, electroencephalography, EEG, computerized cognitive training
Objavljeno v DiRROS: 13.05.2021; Ogledov: 1295; Prenosov: 926
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