Athletes who wish to resume high-level activities after an injury to the anterior cruciate ligament (ACL) are often advised to undergo surgical reconstruction. Nevertheless, ACL reconstruction (ACLR) does not equate to normal function of the knee or reduced risk of subsequent injuries. In fact, recent evidence has shown that only around half of post-ACLR patients can expect to return to competitive level of sports. A rising concern is the high rate of second ACL injuries, particularly in young athletes, with up to 20% of those returning to sport in the first year from surgery experiencing a second ACL rupture. Aside from the increased risk of second injury, patients after ACLR have an increased risk of developing early onset of osteoarthritis. Given the recent findings, it is imperative that rehabilitation after ACLR is scrutinized so the second injury preventative strategies can be optimized. Unfortunately, current ACLR rehabilitation programs may not be optimally effective in addressing deficits related to the initial injury and the subsequent surgical intervention. Motor learning to (re-)acquire motor skills and neuroplastic capacities are not sufficiently incorporated during traditional rehabilitation, attesting to the high re-injury rates. The purpose of this article is to present novel clinically integrated motor learning principles to support neuroplasticity that can improve patient functional performance and reduce the risk of second ACL injury. The following key concepts to enhance rehabilitation and prepare the patient for re-integration to sports after an ACL injury that is as safe as possible are presented: (1) external focus of attention, (2) implicit learning, (3) differential learning, (4) self-controlled learning and contextual interference. The novel motor learning principles presented in this manuscript may optimize future rehabilitation programs to reduce second ACL injury risk and early development of osteoarthritis by targeting changes in neural networks.
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When the pressure is on and anxiety levels increase it is not easy to perform well. In search of mechanisms explaining the anxiety-performance relationship, we revisit the integrated model of anxiety and perceptual-motor performance (Nieuwenhuys and Oudejans, 2012) and provide a critical review of contemporary literature. While there is increasing evidence that changes in attentional control affect the execution of goal-directed action, based on our model and emerging evidence from different scientific disciplines, we argue for a more integrated, process-based approach. That is, anxiety can affect performance on different levels of operational control (i.e., attentional, interpretational, physical) and - moving beyond the execution of action - have implications for different aspects of perceptual-motor behavior, including situational awareness and decision making.
Objective : The first aim of this study was to determine whether adolescents with asymptomatic Generalized Joint Hypermobility (GJH) have a lower level of physical functioning (physical activity level, muscle strength and performance) compared to non-hypermobile controls. Secondly, to evaluate whether the negative impact of perceived harmfulness on physical functioning was more pronounced in adolescents with asymptomatic GJH. Methods : Cross-sectional study. Sixty-two healthy adolescents (mean age 16.8, range 12-21) participated. Hypermobility (Beighton score), perceived harmfulness (PHODA-youth) and muscle strength (dynamometry), motor performance (Single-Leg-Hop-for-Distance) and physical activity level (PAL) (accelerometry) were measured. Hierarchical regression analyses were used to study differences in physical functioning and perceived harmfulness between asymptomatic GJH and non-hypermobile controls. Results : Asymptomatic GJH was associated with increased knee extensor muscle strength (peak torque/body weight; PT/BW), controlled for age and gender (dominant leg; ß = 0.29; p = .02). No other associations between asymptomatic GJH and muscle strength, motor performance and PAL were found. Perceived harmfulness was not more pronounced in adolescents with asymptomatic GJH. Conclusions : Adolescents with asymptomatic GJH had increased knee extensor muscle strength compared to non-hypermobile controls. No other differences in the level of physical functioning was found and the negative impact of perceived harmfulness was not more pronounced in adolescents with asymptomatic GJH.
Paper sludge contains papermaking mineral additives and fibers, which could be reused or recycled, thus enhancing the circularity. One of the promising technologies is the fast pyrolysis of paper sludge, which is capable of recovering > 99 wt.% of the fine minerals in the paper sludge and also affording a bio-liquid. The fine minerals (e.g., ‘circular’ CaCO3) can be reused as filler in consumer products thereby reducing the required primary resources. However, the bio-liquid has a lower quality compared to fossil fuels, and only a limited application, e.g., for heat generation, has been applied. This could be significantly improved by catalytic upgrading of the fast pyrolysis vapor, known as an ex-situ catalytic pyrolysis approach. We have recently found that a high-quality bio-oil (mainly ‘bio-based’ paraffins and low-molecular-weight aromatics, carbon yield of 21%, and HHV of 41.1 MJ kg-1) was produced (Chem. Eng. J., 420 (2021), 129714). Nevertheless, catalyst deactivation occurred after a few hours’ of reaction. As such, catalyst stability and regenerability are of research interest and also of high relevance for industrial implementation. This project aims to study the potential of the add-on catalytic upgrading step to the industrial fast pyrolysis of paper sludge process. One important performance metric for sustainable catalysis in the industry is the level of catalyst consumption (kgcat tprod-1) for catalytic pyrolysis of paper sludge. Another important research topic is to establish the correlation between yield and selectivity of the bio-chemicals and the catalyst characteristics. For this, different types of catalysts (e.g., FCC-type E-Cat) will be tested and several reaction-regeneration cycles will be performed. These studies will determine under which conditions catalytic fast pyrolysis of paper sludge is technically and economically viable.
expressiveness, performance, musicians, skills, educationUsing the genre of Improvisational theatre as a basis, my research aims to design and develop instructional strategies that would help students enhance their expressive skills and achieve the flexibility to adapt their motor behavior to the musical piece. Embodying diverse characters and physicalities, as well as affective states or fictional realities through improv theatre exercises should enable them to expand their expressive range and, therefore, better convey their interpretation to their audience. Through this process, this study also seeks to gain an understanding of the effect this type of training may have on musicians' performance experience, as well as its implications in other areas of their development.
Europa wil in 2050 volledig klimaatneutraal zijn, en zet in op waterstof als energiedrager die een hoofdrol zal spelen in die transitie. Nederlandse bedrijven die dieselaggregaten produceren zetten voor de volledige reductie van de CO2-emissie van hun producten nu voornamelijk in op het vervangen van fossiele door zogenaamde groene diesel. Recent zijn diverse studies verschenen die aantonen dat de ontwikkeling en inzet van waterstofmotoren, zeker voor toepassingen in wegtransport, zowel technisch als economisch zinvol is. Dergelijk productontwikkeling zou ook bij generatorsets een versnelling van de energietransitie mogelijk maken en bovendien kunnen functioneren als een brugtechnologie tot het ogenblik dat brandstofcellen voldoende goedkoop en duurzaam zijn geworden. Doel van dit project is om de economische en technische haalbaarheid van een dergelijke productontwikkeling in kaart te brengen. Bijzonder is daarbij dat het hierbij gaat om een retrofit van bestaande motoren die massaal geproduceerd worden voor automotive doeleinden. Omdat voorlopig gebruik zal worden gemaakt van componenten die ontwikkeld zijn voor de huidige aardgasmotoren voorziet het project ook in versneld duurproefonderzoek van deze componenten. In dit project wordt samengewerkt tussen Fontys Hogeschool Engineering, NPS Diesel B.V., H2Trac B.V., Prins Autogassystemen B.V. en TNO.
