El uso de la tecnología de captura de movimiento para el análisis del rendimiento deportivo

In sport performance, motion capture aims at tracking and recording athletes’ human motion in real time to analyze physical condition, athletic performance, technical expertise and injury mechanism, prevention and rehabilitation. The aim of this paper is to systematically review the latest developments of motion capture systems for the analysis of sport performance. To that end, selected keywords were searched on studies published in the last four years in the electronic databases ISI Web of Knowledge, Scopus, PubMed and SPORTDiscus, which resulted in 892 potential records. After duplicate removal and screening of the remaining records, 81 journal papers were retained for inclusion in this review, distributed as 53 records for optical systems, 15 records for non-optical systems and 13 records for markerless systems. Resultant records were screened to distribute them according to the following analysis categories: biomechanical motion analysis, validation of new systems and performance enhancement. Although optical systems are regarded as golden standard with accurate results, the cost of equipment and time needed to capture and postprocess data have led researchers to test other technologies. First, non-optical systems rely on attaching sensors to body parts to send their spatial information to computer wirelessly by means of different technologies, such as electromagnetic and inertial (accelerometry). Finally, markerless systems are adequate for free, unobstructive motion analysis since no attachment is carried by athletes. However, more sensors and sophisticated signal processing must be used to increase the expected level of accuracy.En el ámbito del rendimiento deportivo, el objetivo de la captura de movimiento es seguir y registrar el movimiento humano de deportistas para analizar su condición física, rendimiento, técnica y el origen, prevención y rehabilitación de lesiones. En este artículo, se realiza una revisión sistemática de los últimos avances en sistemas de captura de movimiento para el análisis del rendimiento deportivo. Para ello, se buscaron palabras clave en estudios publicados en los últimos cuatro años en las bases de datos electrónicas ISI Web of Knowledge, Scopus, PubMed y SPORTDiscus, dando lugar a 892 registros. Tras borrar duplicados y análisis del resto, se seleccionaron 81 artículos de revista, distribuidos en 53 registros para sistemas ópticos, 15 para sistemas no ópticos y 13 para sistemas sin marcadores. Los registros se clasificaron según las categorías: análisis biomecánico, validación de nuevos sistemas y mejora del rendimiento. Aunque los sistemas ópticos son los sistemas de referencia por su precisión, el coste del equipamiento y el tiempo invertido en la captura y postprocesado ha llevado a los investigadores a probar otras tecnologías. En primer lugar, los sistemas no ópticos se basan en adherir sensores a zonas corporales para mandar su información espacial a un ordenador mediante distintas tecnologías, tales como electromagnética y inercial (acelerometría). Finalmente, los sistemas sin marcadores permiten un análisis del movimiento sin restricciones ya que los deportistas no llevan adherido ningún elemento. Sin embargo, se necesitan más sensores y un procesado de señal avanzado para aumentar el nivel de precisión necesario

Concurrent Validity of the Inertial Measurement Unit Vmaxpro in Vertical Jump Estimation

The aim of this study was to evaluate if the inertial measurement unit (IMU) Vmaxpro is a valid device to estimate vertical jump height (VJH) when compared to a motion capture system (MoCAP). Thirteen highly trained female volleyball players participated in this study which consisted of three sessions. After a familiarization session, two sessions comprised a warm-up followed by ten countermovement jumps, resting two min between each attempt. Jump height was measured simultaneously by Vmaxpro using take-off velocity and MoCAP using center-of-mass vertical excursion. Results show significant differences in jump height between devices (10.52 cm; p < 0.001; ES = 0.9), a very strong Spearman’s correlation (rs = 0.84: p < 0.001), and a weak concordance correlation coefficient (CCC = 0.22; ρ = 0.861; Cb= 0.26). Regression analysis reveals very high correlations, high systematic error (8.46 cm), and a nonproportional random error (SEE = 1.67 cm). Bland–Altman plots show systematic error (10.6 cm) with 97.3 % of the data being within the LoA. In conclusion, Vmaxpro can be considered a valid device for the estimation of VJH, being a cheaper, portable, and manageable alternative to MoCAP. However, the magnitude of systematic error discourages its use where indistinguishable data from Vmaxpro and MoCAP are used unless the corresponding specific fitting equation is applied.This work was supported by Generalitat Valenciana (grant number GV/2021/098)

Reliability of My Jump 2 Derived from Crouching and Standing Observation Heights

The crouching or prone-on-the-ground observation heights suggested by the My Jump app are not practical in some settings, so users usually hold smartphones in a standing posture. This study aimed to analyze the reliability of My Jump 2 from the standardized and standing positions. Two identical smartphones recorded 195 countermovement jump executions from 39 active adult athletes at heights 30 and 90 cm, which were randomly assessed by three experienced observers. The between-observer reliability was high for both observation heights separately (ICC~0.99; SEM~0.6 cm; CV~1.3%) with low systematic (0.1 cm) and random (±1.7 cm) errors. The within-observer reliability for the three observers comparing the standardized and standing positions was high (ICC~0.99; SEM~0.7 cm; CV~1.4%), showing errors of 0.3 ± 1.9 cm. Observer 2 was the least accurate out of the three, although reliability remained similar to the levels of agreement found in the literature. The reliability of the mean observations in each height also revealed high reliability (ICC = 0.993; SEM = 0.51 cm; CV = 1.05%, error 0.32 ± 1.4 cm). Therefore, the reliability in the standing position did not change with respect to the standardized position, so it can be regarded as an alternative method to using My Jump 2 with practical added benefits.This research was funded by Generalitat Valenciana, grant number GV/2021/098

The enhancement of fresh produce antioxidant capacity by wounding stress and phytohormones

The use of postharvest abiotic stresses, wounding and plant hormones, can enhance the nutraceutical content of fresh produce. Wounding increased the phenolic content (TP) of carrots, lettuce, jicama, red onions, white onions and celery with a corresponding increase in antioxidant capacity (AOX). Similarly, phenylalanine ammonia lyase (PAL) activity increased with the corresponding increase in total phenolics. The diversity of antioxidant phenolic compounds present in each fresh produce provided specific antioxidant capacities which could be related to important biological activities. The combination of wounding and ethylene (ET) showed a higher increase in TP and AOX for these same tissues. The reason of the synergistic effect is not clear. However, we propose that both stresses may be sharing in part a common signaling molecule that amplifies the response. Studies with carrot tissue identified the individual phenolics responsible for the AOX of wounded and hormone wounded stressed carrots. ET treated carrot tissue showed accumulation of mainly chlorogenic acid (CHA) and dicaffeoylquinic acid (diCQA), but also a slight increase in the synthesis of the bitter compound isocoumarin. On the other hand, the use of methyl jasmonate (MJ) did not increase the levels of isocoumarins but did increase CHA and diCQA. Studies were performed to understand the mechanism by which wounding and hormone stress stimulated the phenylpropanoid metabolism. The blockers phenidone (PHE), diphenyleneiodonium (DPI), and 1-methylcyclopropene (1MCP) provided information relevant to signaling molecules including reactive oxygen species (ROS), MJ and ET, and their effect on the synthesis of TP. Results with DPI blocker suggest that ROS are greatly responsible for the accumulation of phenolics in wounded- and wounded-hormone stressed carrot tissue

Defensive systems during the Men’s European University Beach Volleyball Championship

The analysis of performance in beach volleyball should consider the development of the set or game systems in connection with successful completion. In this paper, we present a study of defensive system in university beach volleyball players in order to determine the evolution throughout the set and effectiveness in relation to the performance factors of the game. A total of n=937 blocking actions were analyzed by means of video recordings from 24 European men's teams from 16 different nationalities at the Ninth European Beach Volleyball Championship EUSA GAMES. The analysis of the videos was carried out using the free software program LongoMatch v.0.27 by an experienced observer. Reliability performed on the intra-observer analysis showed a margin of error lower than 5%. Both effectiveness of the game systems and frequency of winning and not winning points were annotated for each period of points. Statistical significance of the comparison of systems was calculated using the Z test to compare proportions. Results showed that the most widely used game system was 2:1 with 67.2% (n=630) with statistically significance (p<0.001). Regarding effectiveness, system 2:1 presented an efficiency of success of 30.8% (n=194), whereas system 1:2 presented a moderately low value of 25.7% (n=79). When comparing periods of points (F1:1 to 7, F2: 8 to 14, F3: 15 to 21), system 2:1 showed higher effectiveness than 1:2 for the last two periods F2 and F3. Finally, a decrease in unscored point actions was observed in both systems between periods F1 to F3 (59.63% for 1:2 and 45.35% for 2:1)

Validity, reliability and usefulness of smartphone and kinovea motion analysis software for direct measurement of vertical jump height

Jumping is a simple exercise determined by several biomechanical and physiological factors. Measures of vertical jump height are common and easy to administer tests of lower limb muscle power that are carried out with several types of equipment. This study aimed to validate and address the usefulness of the combination of smartphone and computer-based applications (Smartphone-Kinovea) against a laboratory-based Motion Capture System. One hundred and twelve healthy adults performed three maximal-effort countermovement jumps each. Both instruments measured the heights of the 336 trials concurrently while tracking the excursion of the body center of gravity. The vertical velocity at take-off vto and the impulse J were computed with jump height h measures. Intraclass correlation coefficient (ICC) results indicated very high agreement for h and vto (0.985) and almost perfect agreement for J (0.997), and Cronbach's α=0.99. Low mean differences were observed between instruments for h: -0.22 ± 1.15 cm, vto: -0.01 ± 0.04 m/s, and J: -0.56 ± 2.92 Ns, all p1). Bland-Altman plots showed very low mean systematic bias ± random errors (-0.22 ± 2.25 cm; -0.01 ± 0.08 m/s; -0.56 ± 5.73 Ns), without association between their magnitudes (r2=0.005, r2=0.005, r2=0.001). Finally, very high to practically perfect correlation between isntruments were observed (r = 0.985; r = 0.986; r = 0.997). Our results suggest that the Smartphone-Kinovea method is a valid and reliable, low-cost instrument to monitor changes in jump performance in a healthy, active population diverse in gender and physical condition.This work was supported by the Vice-rectorate program of Research and Knowledge transfer for the Promotion of R&D at the University of Alicante (Ref. GRE18–19)

Reliability and validity of the Chronojump open-source jump mat system

Vertical jump performance is a commonly used test to measure lower-limb muscle power that is carried out with several types of equipment. The aim of this study was to validate an open-source jump mat (Chronojump Boscosystems) against a proprietary jump mat (Globus Ergo Tester). Sixty-three active sportsmen (age 23.3 ± 2.4 years) completed 8 maximal-effort countermovement jumps (CMJ). The heights of the 504 CMJ were measured from the two jump mats simultaneously. Reliability was examined with intra-class correlation coefficients (ICC), paired samples t-tests, coefficient of variation (CV) and Cronbach's ?. Bivariate Pearson's correlation coefficient (r) was used to examine validity. Effects were evaluated using non-clinical magnitude based inference. There was almost perfect agreement between instruments (ICC = 0.999?1.000, most likely positive 100/0/0). Paired t-test showed a mean difference of 0.03 ± 0.21 cm (90% CI -0.04 ? -0.01) between instruments (most likely trivial 0/100/0). Both instruments showed very good stability (? = 1.00, CV = 4.28±1.95%). The smallest worthwhile change and typical error values were 1.3 and 0.29 cm, respectively and therefore, the signal-to-noise ratio of both instruments was large: 4.5. Finally, almost perfect correlation between instruments was observed (r = 0.999, most likely positive 100/0/0). Chronojump can be regarded as a sensitive instrument to detect changes in jump height performance over the possible noise around the measure. The results supported the open-source jump mat to be a useful, valid and reliable, low-cost testing device to monitor variations in vertical jumping performance

Diplomado de profundización cisco prueba de habilidades prácticas ccnp

Mediante la topología de redes propuesta, se ha desarrollado un ejercicio práctico utilizando los softwares GNS3 y VirtualBox. Inicialmente se construye la red con componentes CISCO, y se hace la configuración de los dispositivos utilizados (router, switch, PC). La conexión se realiza de acuerdo a la tabla de enrutamiento, en la cual se han utilizado algunos valores que coinciden con los tres últimos dígitos de la cédula. Para dividir la accesibilidad de los usuarios, se utiliza el enrutamiento VRF asignando usuarios especiales y usuarios generales, todo implementado mediante los diferentes comandos aplicables en GNS3. De igual forma, se asignan las rutas estáticas en los router, para entablar la comunicación y permitir el flujo de datos, con la conmutación de accesibilidad planteada. La configuración realizada en la red, plantea como base, el uso de los conocimientos en electrónica y el desarrollo de los cursos en redes para CCNP, incluyendo los parámetros de seguridad para la correcta operación.Through the proposed network topology, a practical exercise has been developed using the GNS3 and VirtualBox software. Initially, the network is built with CISCO components, and the configuration of the devices used (router, switch, PC) is done. The connection is made according to the routing table, in which some values have been used that coincide with the last three digits of the ID. To divide the accessibility of users, VRF routing is used assigning special users and general users, all implemented through the different applicable commands in GNS3. In the same way, the static routes are assigned in the routers, to establish communication and allow the flow of data, with the accessibility switching proposed. The configuration carried out in the network, raises as a basis, the use of knowledge in electronics and the development of network courses for CCNP, including the security parameters for correct operation

Control de inventarios de mercaderías y su incidencia en la formulación del estado de situación financiera y resultados en la Distribuidora Europea de Repuestos S. A. C., Ate, 2020

La presente tesis titulado control de inventarios de mercaderías y su incidencia en la formulación de los estados de situación financiera y resultados en la Distribuidora Europea de Repuestos SAC, Ate, 2020 tiene como objetivo de determinar las incidencias del control de inventarios para con la formulación de los estados de situación financiera y de resultados que al no contar con información de control de inventarios, políticas de compras inciden de forma positiva o negativa en la formulación del estado situacional y de resultados, para ello se fue conceptualizando cada una de las variables con la finalidad de obtener mayor información para así tener una observación más amplia sobre las variables

Innovative Mobile Manipulator Solution for Modern Flexible Manufacturing Processes

There is a paradigm shift in current manufacturing needs that is causing a change from the current mass-production-based approach to a mass customization approach where production volumes are smaller and more variable. Current processes are very adapted to the previous paradigm and lack the required flexibility to adapt to the new production needs. To solve this problem, an innovative industrial mobile manipulator is presented. The robot is equipped with a variety of sensors that allow it to perceive its surroundings and perform complex tasks in dynamic environments. Following the current needs of the industry, the robot is capable of autonomous navigation, safely avoiding obstacles. It is flexible enough to be able to perform a wide variety of tasks, being the change between tasks done easily thanks to skills-based programming and the ability to change tools autonomously. In addition, its security systems allow it to share the workspace with human operators. This prototype has been developed as part of THOMAS European project, and it has been tested and demonstrated in real-world manufacturing use cases.This research was funded by the EC research project “THOMAS—Mobile dual arm robotic workers with embedded cognition for hybrid and dynamically reconfigurable manufacturing systems” (Grant Agreement: 723616) (www.thomas-project.eu/)