Augment d’alçada en salt en jugadors universitaris de voleibol

L’entrenament del salt és fonamental per obtenir un òptim acompliment en diversos esports, sent el mètode complex, basat en el fenomen de potenciació postactivació (PPA), un dels més utilitzats per a l’entrenament d’aquesta qualitat. Nombrosos estudis recolzen l’existència de PPA representada en les variacions d’un salt vertical, no obstant això, en la literatura no es descriu un protocol estàndard d’entrenament que generi aquest fenomen. Aquest estudi pilot quantitatiu quasi experimental té com a objectiu determinar en quina de les zones de força descrites per Naclerio s’ha d’entrenar perquè la PPA s’expressi, en major mesura, evidenciat en les variacions d’altura d’un salt Counter Movement Jump (CMJ). Es va utilitzar un mostreig per conveniència de vint-i-cinc individus, dividits aleatòriament en cinc grups, cadascun corresponent a una zona de força. Després els subjectes van ser entrenats amb mig esquat segons els paràmetres de cada zona. Finalment, es va obtenir l’altura del salt basant-se en la fórmula de Bosco a partir dels fotogrames d’una càmera digital. Es van trobar dues zones de força que van presentar un augment en l’altura del salt posterior a la potenciació, la zona de força potència i explosiva, no obstant això solament la primera d’aquestes va mostrar resultats significatius en aquest canvi (p < 0,05), representats com un 7 % d’augment. Pretenem que aquestes troballes siguin útils per al desenvolupament de nous estudis que permetin el disseny de noves metodologies d’entrenament i rehabilitació esportiva veient-se beneficiats per les seves propietats

Mechanical determinants of sprinting and change of direction in elite female field hockey players

Profile determination in field hockey is critical to determining athletes’ physical strengths and weaknesses, and is key in planning, programming, and monitoring training. This study pursued two primary objectives: (i) to provide descriptive data on sprinting, deceleration, and change of direction (COD) abilities and (ii) to elucidate the mechanical variables that influence sprint and COD performance in elite female field hockey players. Using radar and time-gate technology, we assessed performance and mechanical data from 30 m sprinting, deceleration, and COD tests for 26 elite female hockey players. A machine learning approach identified mechanical variables related to sprint and COD performance. Our findings offer a framework for athlete categorization and the design of performance-enhancing training strategies at the international level. Two pivotal mechanical variables—relative maximum horizontal force (F0) and maximum velocity (Vmax)—predominantly influence the times across all tested distances. However, the force–velocity profile (FVP) and horizontal deceleration do not influence the variance in the COD test outcomes. These insights can guide the design, adjustment, and monitoring of training programs, assisting coaches in decision making to optimize performance and mitigate injury risks for female hockey players

ISOKINETIC STRENGTH IN FEMALE SOCCER PLAYERS BY PLAYER POSITION

This study aimed to establish reference values and compare isokinetic performance in female soccer players according to player position. Eighty-seven female soccer players from the Chilean first-division soccer clubs were evaluated in isokinetic strength. The player position was grouped as goalkeeper (GK), central defender (CD), lateral defender (LD), midfielder (MF), and forward (FW). Concentric knee extension and flexion muscle strength measurements were conducted using a standardized test protocol with an angular velocity of 60º/sec. There were no differences in peak torque of knee extension and flexion between player positions in both the dominant leg (DL) and the nondominant leg (NDL). The H:Q ratio shows significant differences (p=0.0379) in the dominant leg between CD vs. MF (GK: 63.1±11.1; CD: 55.6±4.6; LD: 62.5±9.6; MF: 64.8±12.0; FW: 61.1±10.9). Our results can be used for practitioners working with female professional soccer players to assess and monitor strength according to player position to improve performance. Future studies should confirm whether these values can be used as risk factors, complementing other functional metrics (e.g., eccentric force) and different angular velocities

ELECTROMYOGRAPHIC INTER-LIMB ASYMMETRY IN BENCH PRESS EXERCISE IN ELITE PARALYMPICS WEIGHTLIFTERS

The purpose of this study was to describe inter-limb asymmetry in three muscle groups in a sample of Paralympic weightlifters during an 80% RM bench press. The sample was composed of 7 subjects belonging to the Chilean elite powerlifting. Surface electromyography was assessed in major pectoral, deltoid anterior and triceps brachii. The magnitude of the response was calculated through root mean square (RMS). Symmetry Index was calculated for an interlimb differences measure. Only the pectoralis major muscle showed significant differences between limbs (right 84.7 ± 41.3; left 66.1 ± 19.3 RMS) (p=0.05) and the SI median greatest value (19.74 ± 24.59%). Anterior deltoid showed high individual differences in two athletes with upper 80% SI values. More studies should assess asymmetry with the objective to decrease this injuries risk factor

PHYSICAL AND BIOMECHANICAL ASPECTS THAT CAN INFLUENCE THE PREFERENCE FOR THE UCHIMATA TECHNIQUE IN JUDO: A CASE STUDY

The aim of this study was to compare the handgrip strength, flexibility level (sit and reach test), kumikata and biomechanical aspects of the uchimata technique of two national level judokas, one who favors to use the uchimata (tokui-waza), and one who selects another judo technique in combat. We recorded the highest value of three attempts for handgrip strength (handgrip test), and flexibility (sit and reach); we recorded the highest value of three attempts for strength (handgrip test) and flexibility (sit and reach test); we analyzed the uchimata phases (kuzushi, tsukuri, kake and zanshi) in 3D using Vicon® system. We found that non-traditional kumikata during combat (grips with both hands on the same side), greater level of flexibility (45 vs. 36 cm), greater leg opening distance (113 vs. 66 cm) and greater displacement speed of the center of mass performing the technique (75 vs. 49 cm/s) may be indicators for the choice of uchimata technique as tokui-waza

INCIDENCES OF STIFFNESS ON SQUAT JUMP VARIABLES

The purpose of this study was to relation level the stiffness of the patellar tendon and three portions of the Achilles tendon; inferior, middle, and superior location with performance variables in the squat jump. The sample was composed of 25 belonging to Chilean elite male handball players. It assesses stiffness tendinous patellar and Achilles tendon using to MyotonPro® device. During the squat jump assessment, two force platforms Pasco and ForceDecks® software for analysis. The main results were RFD 0-50 ms (r=0.611), RFDN 0-50 ms (r=0.550), RFD 0-100 ms (r=0.615), and RFDN 0-100 ms (r=0.624) presented a relationship with patellar stiffness, while that Achilles tendon was down relation with peak power in squat jump (r=472). This information can be useful for training judo athletes. From the results, it can be concluded that the stiffness of the patellar tendon and the Achilles tendon determine some mechanical variables of the SJ, mainly in relation to the RFD

CIBERER : Spanish national network for research on rare diseases: A highly productive collaborative initiative

Altres ajuts: Instituto de Salud Carlos III (ISCIII); Ministerio de Ciencia e Innovación.CIBER (Center for Biomedical Network Research; Centro de Investigación Biomédica En Red) is a public national consortium created in 2006 under the umbrella of the Spanish National Institute of Health Carlos III (ISCIII). This innovative research structure comprises 11 different specific areas dedicated to the main public health priorities in the National Health System. CIBERER, the thematic area of CIBER focused on rare diseases (RDs) currently consists of 75 research groups belonging to universities, research centers, and hospitals of the entire country. CIBERER's mission is to be a center prioritizing and favoring collaboration and cooperation between biomedical and clinical research groups, with special emphasis on the aspects of genetic, molecular, biochemical, and cellular research of RDs. This research is the basis for providing new tools for the diagnosis and therapy of low-prevalence diseases, in line with the International Rare Diseases Research Consortium (IRDiRC) objectives, thus favoring translational research between the scientific environment of the laboratory and the clinical setting of health centers. In this article, we intend to review CIBERER's 15-year journey and summarize the main results obtained in terms of internationalization, scientific production, contributions toward the discovery of new therapies and novel genes associated to diseases, cooperation with patients' associations and many other topics related to RD research

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Caso sobre la crisis de la Industria Electrica en Chile, anos 1998-1999 : cuando la lluvia no llega

131 p