Muscular Activity of the Posterior Deltoid During Swimming vs. Resistance Exercises on Water and Dry Land

The purpose of this study was to compare muscular activity of the posterior deltoid muscle during three typical aquatic physical conditioning activities. This interpretative case study involved a 23 year old elite swimmer and athlete. Muscular activity was measured with surface electromyography during swimming crawl at maximum speed, and also while performing horizontal shoulder abduction using elastic band and Hydro-Tone Bells resistance. During the maximum voluntary contraction, we observed what appeared to be meaningful differences between the percentage of muscular activation during the swimming activity and that observed during the elastic band and aquatic resistance exercises (18.72% vs. 74.84% and 65.46%, respectively). No meaningful differences were observed between the percentage of muscular activation for the elastic band and aquatic resistance exercises. Resistance exercises, both in and out of the water, produce more muscle activation and may be more efficient for improving muscular strength than sprint crawl swimming

Effects of an incremental maximal endurance exercise stress-induced cortisol on cognitive performance

Objectives: It can be hypothesized that cognitive performance decreases after fatigue protocol when it coincides with the maximum peak of cortisol. The first aim of this study was to elucidate the effects of a single bout of high intensity exercise on behavioural (i.e., attention and memory) and physiological (i.e., salivary cortisol) responses. The second objective was to evaluate the effect of the performance of the cognitive tasks on cortisol levels. Methods: Thirty-four physically active men (at least 5 days/week of physical activity practice) 38.11 (1.57) years old completed a maximal incremental protocol on a treadmill by running until they reached a state of stress. Salivary cortisol and cognitive functions were evaluated in counterbalanced order prior and following exercise-induced stress. Results: Results showed lower cortisol levels before exercise and higher cortisol values before the cognitive task. Indeed, exercise-induced stress had only a detrimental effect on attention without any impact on declarative memory and finding improvements on working memory performance. Conclusion: The effects of stress on cognitive performance depending on the main brain areas responsible of cognitive functions (i.e., prefrontal cortex and hippocampus) and time elapsed between the cessation of exercise and the evaluation of these

New strategies in proprioception’s analysis for newer theories about sensorimotor control

[EN] Human’s motion and its mechanisms had become interesting in the last years, where the medecine’s field search for rehabilitation methods for handicapped persons. Other fields, like sport sciences, professional or military world, search to distinguish profiles and ways to train them with specific purposes. Besides, recent findings in neuroscience try to describe these mechanisms from an organic point of view. Until now, different researchs had given a model about control motor that describes how the union between the senses’s information allows adaptable movements. One of this sense is the proprioception, the sense which has a quite big factor in the orientation and position of the body, its members and joints. For this reason, research for new strategies to explore proprioception and improve the theories of human motion could be done by three different vias. At first, the sense is analysed in a case-study where three groups of persons are compared in a controlled enviroment with three experimental tasks. The subjects belong to each group by the kind of sport they do: sedentary, normal sportsmen (e.g. athletics, swimming) and martial sportmen (e.g. karate, judo). They are compared thinking about the following hypothesis: “Martial Sportmen have a better proprioception than of the other groups’s subjects: It could be due to the type of exercises they do in their sports as empirically, a contact sportsman shows significantly superior motor skills to the members of the other two groups. The second via are records from encephalogram (EEG) while the experimental tasks are doing. These records are analised a posteriori with a set of processing algorithms to extract characteristics about brain’s activity of the proprioception and motion control. Finally , the study tries to integrate graphic tools to make easy to understand final scientific results which allow us to explore the brain activity of the subjects through easy interfaces (e.g. space-time events, activity intensity, connectivity, specific neural netwoks or anormal activity). In the future, this application could be a complement to assist doctors, researchers, sports center specialists and anyone who must improve the health and movements of handicapped persons.[ES] Existe un creciente interés sobre la motricidad humana y sus mecanismos en los últimos años, donde el campo de la medicina investiga métodos de rehabilitación para personas con movilidad reducida. Otros campos, como las ciencias del deporte, el mundo profesional o el militar, buscan discriminar entre perfiles y entrenarlos con fines específico. Además, recientes hallazgos en neurociencia intentan analizar estos mecanismos desde un punto de vista orgánico. Hasta ahora, diferentes investigaciones han conducido a un modelo del control sensorimotor, que describe cómo la interacción entre las diferentes vías sensoriales permite la motricidad adaptativa. En este campo, la propiocepción, que se define como el sentido de la orientación y posición del cuerpo, de sus partes y de las articulaciones que las unen, ha adquirido un papel relevante. Por esta razón, la búsqueda de nuevas estrategias para explorar la propiocepción y mejorar las teorías de la moción humana es abordada por tres vías distintas. La primera de ellas analiza la propiocepción en un caso estudio, en el que tres grupos de participantes son comparados en un entorno controlado de tres protocolos experimentales. Los tres grupos se distinguen por su entrenamiento deportivo: sedentarios, deportistas de carácter general (e.g. atletismo, natación) y deportistas marciales (e.g. karate, judo). La hipótesis de la comparación es “Los deportistas marciales tienen una mejor propiocepción que los otros dos grupos, lo cual se debe al tipo de deporte que practican, o porque la gente con mejores habilidades terminan practicando dichos deportes”. La segunda aproximación son capturas de señales de electroencefalograma (EEG) mientras los sujetos ejecutan las tareas experimentales. Los resultados obtenidos son analizados a posteriori con diferentes algoritmos de procesado para extraer parámetros de la actividad nerviosa asociada a la propiocepción y al control motor. Por último, el estudio intenta integrar herramientas gráficas que faciliten entender los resultados científicos y explorar la actividad cerebral a través de interfaces intuitivas (e.g. eventos espacio-temporales, intensidad de la actividad, conectividad, rutas neuronales específicas o actividad anormal). En el futuro, está aplicación podría ser un complemento para médicos, investigadores, asesores en centros deportivos de alto rendimiento o cualquier otro profesional que deba mejorar la salud y la movilidad para personas discapacitadas.Muñoz Rodriguez, D.; Santiago Praderas, VM.; Garcia Casado, FJ.; Garcia Masso, X.; González García, E.; Dunai Dunai, L. (2017). New strategies in proprioception’s analysis for newer theories about sensorimotor control. En Systems & Design: From Theory to Product. Editorial Universitat Politècnica de València. 99-120. https://doi.org/10.4995/SD2017.2017.6903OCS9912

Neural Network for Estimating Energy Expenditure in Paraplegics from Heart Rate

The aim of the present study is to obtain models for estimating energy expenditure based on the heart rates of people with spinal cord injury without requiring individual calibration. A cohort of 20 persons with spinal cord injury performed a routine of 10 activities while their breath-by-breath oxygen consumption and heart rates were monitored. The minute-by-minute oxygen consumption collected from minute 4 to minute 7 was used as the dependent variable. A total of 7 features extracted from the heart rate signals were used as independent variables. 2 mathematical models were used to estimate the oxygen consumption using the heart rate: a multiple linear model and artificial neural networks. We determined that the artificial neural network model provided a better estimation (r = 0.88, MSE = 4.4 ml.kg(-1).min(-1)) than the multiple linear model (r = 0.78; MSE = 7.63 ml.kg(-1).min(-1)). The goodness of fit with the artificial neural network was similar to previous reported linear models involving individual calibration. In conclusion, we have validated the use of the heart rate to estimate oxygen consumption in paraplegic persons without individual calibration and, under this constraint, we have shown that the artificial neural network is the mathematical tool that provides the better estimation.L. M. Garcia-Raffi and E. A. Sanchez-Perez gratefully acknowledge the support of the Ministerio de Economia y Competitividad under project #MTM2012-36740-c02-02. X. Garcia-Masso is a Vali + D researcher in training with support from the Generalitat Valenciana.Garcia Masso, X.; Serra Añó, P.; García-Raffi, LM.; Sánchez Pérez, EA.; Giner-Pascual, M.; González, L. (2014). Neural Network for Estimating Energy Expenditure in Paraplegics from Heart Rate. International Journal of Sports Medicine. 35(12):1037-1043. doi:10.1055/s-0034-1368722S10371043351

First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data

International audienceSpinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signal-to-noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of 11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far