184 research outputs found

    Evaluation of muscle energy in isometric maintenance as an index of muscle fatigue in roller speed skating

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    Roller speed skating is a discipline in which muscle fatigue plays an important role in athletes; in this work, we wanted to evaluate whether a methodological approach based on the energy required to maintain an isometric muscle contraction for one minute, indexed on the MVIC (maximum voluntary isometric contraction), i.e. % RMS/MVIC can give results similar to the frequency decay analysis/time in terms of usability for athlete training and injury prevention. Right and left gluteus maximus and vastus lateralis muscles (involved in the propulsive phase of skating ) were examined separately by surface electromyography in three competitive athletes in short-track speed skating on asphalt. The results showed an asymmetry between the right (less resistant) and left (more resistant) lower limb, in all three athletes, from the point of view of fatigue, in both investigated muscles. Furthermore, a trend in terms of fatigue resistance was found that was directly proportional to skill in both muscles studied. This can be of help in better planning the training of street speed skaters (which although similar to the discipline on ice is not completely superimposable) with the dual purpose of improving their performance and preventing injuries, often linked to the degree of right-left muscle asymmetry

    Roller Speed Skating Kinematics and Electromyographic Analysis: A Methodological Approach

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    Roller speed skating is a discipline similar to hockey and ice skating from a biomechanical point of view, but there are no specific functional protocols for rehabilitation and performance improvement for these athletes. The aim of the study is to create a dedicated functional, kinematic and electromyographic protocol to be used as a tool for future studies on the subject. The protocol was created, starting from a correct and repeatable movement as a case study, on a world speed skating champion, using an inertial sensor positioned at the level of the first sacral vertebra, eight electromyographic probes positioned on one or the other lower limb, and a high-definition camera at 50 Hz. The results show the electromyographic activity of the muscles investigated, the degree of absolute muscle activation and compared to their maximum voluntary isometric contraction (MVIC), the level of co-activation of the agonist/antagonist muscles, and the accelerations of the body on the three axes of space. The results will represent the basis for physiotherapy and specific training use. Future developments will include the analysis of a sample of elite athletes to be able to build a normal range on the parameters investigated, and the possibility of treating in the most appropriate way possible muscle injuries (which mostly occur in the groin in such athletes) once they have occurred, even with oriented MVIC or co-activation oriented exercises

    Pulsed radiofrequency on peripheral nerve as a rehabilitation aid

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    The work described below explores the field of the effects of pulsed radiofrequency for pain relief purposes. While the effects of this technique on pain modulation (A-delta and C fibers) are relatively well-known, little has been written yet about the potential of pulsed radiofrequency interactions with other fibers. The proposed algorithm, specifically elaborated, investigates the effect of this technique on neuromuscular fatigue, through a surface electromyographic study of the femoral nerve of a patient with residual pain after knee arthroplasty surgery, before and after the treatment. This work yields a preliminary result that is encouraging for subsequent large-scale studies

    Climate scenario analysis:An illustration of potential long-term economic & financial market impacts

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    This paper illustrates the potential impacts of climate change on financial markets, focusing on their long-term significance. It uses a top-down modelling tool developed by Ortec Finance in partnership with Cambridge Econometrics that combines climate science with macro-economic and financial effects to examine the possible impacts of three plausible (not extreme) climate pathways. The paper first considers the impact on gross domestic product (GDP), finding that GDP is lower in all three pathways, with the most severe reduction in the Failed Transition Pathway where the Paris Agreement climate targets are not met. The model then translates these GDP impacts into financial market effects. In the Failed Transition Pathway, cumulative global equity returns are approximately 50% lower over the period 2020–2060 than in the climate-uninformed base case. For the other two pathways where the Paris Agreement targets are met, the corresponding figures are 15% and 25% lower returns than in the base case. Results are provided for other asset classes too. These demonstrate that climate change represents a significant market risk, with implications for financial planning, modelling and regulation

    Climate Scenario analysis for pension schemes:a UK case study

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    This paper demonstrates how climate scenario analysis can be used for forward-looking assessment of the risks and opportunities for financial institutions, using a case study for a UK defined benefit pension scheme. It uses a top-down modelling tool developed by Ortec Finance in partnership with Cambridge Econometrics to explore the possible impacts of three plausible (not extreme) climate pathways of the scheme’s assets and liabilities. It finds that the funding risks are greater under all three climate pathways than under the climate-uninformed base scenario. In the absence of changes to the investment strategy or recovery plan, the time taken to reach full funding is increased by three to nine years. Given that most models currently used by actuaries do not make explicit adjustments for climate change, these modelled results suggest it is quite likely that pension schemes are systematically underestimating the funding risks they face
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