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Background/Aims: Asymmetry of the internal (IR) and external (ER) shoulder rotators can increase the risk of injuries in judokas. Discrete analyses are usually performed in time series data, but they can have biases by removing trends, so other approaches have been proposed to avoid these biases such as statistical parametric mapping (SPM) and principal component analysis (PCA). This study analyzed the asymmetry in the shoulder rotators in female judokas, comparing dominant (D) vs. non-dominant (ND) upper limbs. Methods: For this, 11 elite athletes (age: 20.1 ± 2.9 yrs.; experience: 4.0 ± 0.5 yrs.; body mass: 66.0 ± 14.6 kg; height: 1.6 ± 0.1 m; BMI: 24.8 ± 4.3 kg/m2), were evaluated in an isokinetic dynamometer (Cybex® Humac/Norm Dynamometer CSMI, 502140, Stoughton, MA, USA). All participants performed the concentric (CON/CON) isokinetic evaluations of internal and external rotation of the shoulder in 60°/s and 180°/s angular velocities. Results: There was no significative asymmetry between IR vs. ER at 60°/s; similar results were observed at 180°/s when analyzed by PCA or SPM methods (p > 0.05 for all comparison). There was no difference between peak torque at 60°/s or 180°/s (p > 0.05 for all comparison). Conclusions: no asymmetry was observed in IR and ER in elite female athletes, regardless of the analysis method.

Introduction: SARS-CoV-2 acutely affects human pulmonary function, and respiratory alterations may persist after overcoming the infection. Objectives: To characterize the pulmonary function among Colombian survivors of COVID-19. Methods: A pilot study was conducted where pulmonary function was assessed using a MiniBox™ device, aerobic fitness with a six-minute walk test, and fatigue perception with the Multidimensional Fatigue Inventory (MFI-20). Results: Out of an initial group of 70 participants, only 39 completed the study, with a disease course ranging from mild to moderate. Women comprised the majority (51%) of the participants, and no abnormal values were found in pulmonary function. The total fatigue score was 39 ± 9.2; for general fatigue, it was 5 ± 0, the same as for physical fatigue (5 ± 0); for mental fatigue, the score was 8.56 ± 3.5; for reduced activity, it was 11.2 ± 2.96, and for reduced motivation, it was 9.38 ± 4.4. Additionally, the peak oxygen co sumption (VO2 peak) was 19.51 ml/kg/min ± 2.8 ml/kg/min. Conclusions: Pulmonary function and fatigue levels in Colombian COVID-19 survivors residing in Bogotá who did not require ventilatory support were normal according to the tests performed, while cardiopulmonary fitness was low.

Introduction: Combat sport athletes are more likely to suffer concussions because one of the goals is to knock out an opponent and apply blows during the fight. Objective: To analyze the mechanisms of concussion specific to combat sports and identify the most prevalent signs and symptoms that affect athletes after concussion. Methods: The PRISMA protocol was applied, searches were performed in electronic databases using the descriptors: Athletes, Fighting, Martial Arts, Combat Sports, Concussion, Brain Concussion, Traumatic Brain Injury, Physical Symptoms and Motivational Symptoms. The identification and peer selection process were performed using the Rayyan software. We then extracted the articles which met the eligibility criteria for qualitative analysis, using the Risk of Bias Used for Surveys tool. Results: A total of 912 articles were identified, 90 duplicates and 81 bibliographic reviews, leaving 65 articles for reading the abstracts. Of these, 46 were excluded according to the eligibility criteria, including 19 articles. Regarding exposure to concussion, 70.2% were related to the number of fights performed and 29.8% fighters. The sports modalities were 45.5% MMA, 18.2% boxing, 9.1% taekwondo, 9.1% karate and 9.1% kickboxing. The injuries found were divided into 27.2% traumatic brain injury and 72.8% concussion. According to the signs and symptoms identified, 55.2% were physical and 44.8% motivational. Conclusion: The frequency of fights is a determining factor for the incidence of concussions in combat sport athletes and the post-concussion symptoms showed significant physical and motivational manifestations, which represent barriers to the technical-tactical development of athletes.

Introducción: El rendimiento físico en jóvenes futbolistas puede estar influenciado por la composición corporal, las medidas antropométricas y el estado de maduración. Este estudio examina cómo estas variables afectan la fuerza isométrica, el salto vertical y el cambio de dirección. Objetivo: Analizar el impacto de la masa grasa, la masa magra, las medidas antropométricas y el estado de maduración en el rendimiento físico de jóvenes futbolistas. Metodología: Se realizó un estudio correlacional con jugadores de un equipo de fútbol chileno (N=34; 16.06 ± 0.78 años; 1.69 ± 0.06 m; 62.39 ± 8.26 kg), utilizando un escáner DEXA para evaluar la composición corporal y pruebas físicas (cambio de dirección; tirón isométrico de muslo medio y salto con contramovimiento) para medir el rendimiento. Se empleó un modelo de regresión LASSO para identificar predictores significativos. Resultados: Las variables antropométricas, la composición corporal y el APHV explican el porcentaje de varianza en el modelo en diferentes magnitudes (R² 0.05 a 0.78) con tamaños del efecto medios y grandes (f² de Cohen 0.6 a 3.0). Conclusión: La composición corporal y el estado de maduración son cruciales para optimizar el rendimiento en jóvenes futbolistas.

Abstract. Objective: This study aimed to investigate the intra-test reliability of countermovement push-up (CMPU) in semi-professional kickboxing athletes and to analyze the association with anthropometric measurements of the upper limb. Methods: 8 semi-professional kickboxing athletes (7 male and 1 female athletes) underwent a series of assessments, including skinfold thickness, limb circumference measurements, and the CMPU test with force platforms. Intraclass correlation coefficients (ICC) and coefficients of variation (CV%) were calculated for CMPU variables. Additionally, Spearman correlation coefficients were computed to assess the relationship between upper limb anthropometric data and CMPU variables derived from the force platform. Results: The ICC and CV% values indicated that the analyzed performance variables exhibited reliability ranging from poor to excellent (ICC = 0.65–0.77, CV% = 5.6–20.8). Push-off time and rate of power development concentric demonstrated unclear reliability (ICC = 0.15–0.31, CV% = 7.5–14.9), while rate of force development braking showed poor to good reliability (ICC = 0.44, CV% = 27.4). Strong to very strong correlations were observed between relaxed arm circumference, contracted arm circumference, forearm circumference, bicipital fold, and concentric impulse, peak force, and peak power. Conclusion: The results of this study emphasize the reliability of CMPU testing in semi-professional kickboxing athletes, making it a potentially valuable tool for monitoring upper limb force and power variables. Additionally, the robust correlations suggest that variations in upper limb circumference can significantly influence force and power generation during the CMPU test. These findings have implications for training program design and performance assessment in activities reliant on upper body strength and power, such as kickboxing. Keywords: biomechanics, kinetic, kinematic, martial arts, combat sport.

Objective: This study aims to assess the performance of professional soccer teams from different divisions and playing positions using the 30-15 intermittent fitness test (30-15 IFT). Methods: The sample comprised 84 male soccer players from first division teams A (1A) (n=21; mean age 23.5±5.2 years), first division B (1B) (n=42; mean age 23.0±5.0), and second professional division (2nd) (n=21; mean age 22.9±4.7 years). Performance was evaluated based on the final speed achieved in the 30-15 IFT (VIFT). Results: Significant differences were observed between 1A and both 1B and 2nd in VIFT (p=0.002, n2p=0.115). Additionally, differences were found between defenders and full-backs in VIFT (p=0.002, n2p=0.197). Conclusion: Performance in the 30-15 IFT varies across divisions, with 1A achieving the highest values. Moreover, full-backs demonstrated superior performance compared to defenders. These findings provide valuable insights for coaches, physical trainers, and sports scientists for optimizing training programs. Keywords: soccer, exercise test, physical fitness, athletic performance

This study investigates the acute effects of CrossFit training on cognition and physiological parameters across different performance stages. We focused on evaluating the impact of such training on both the mental and physical performance of athletes classified as Elite, Advanced, and Beginners. The objective was to explore how CrossFit, known for its high-intensity and varied functional movements, influences cognitive functions and physiological responses in athletes of varying expertise. By comparing these groups both before and after the Workout of the Day (WOD), we aimed to understand the relationship between CrossFit training intensity and cognitive and physiological changes. Methodologically, our approach involved categorizing our sample into three groups: Elite (n=7), Advanced (n=10), and Beginners (n=15). We conducted comprehensive assessments of each participant's cognitive and physiological parameters pre- and post-WOD. The results revealed notable differences in performance time, with Elite athletes showing significantly quicker times compared to Advanced and Beginners. Cognitive functions, particularly executive functions like reading, counting, choice-making, shifting, inhibition, and flexibility, also varied significantly across the groups. Physiological measurements, including lactate stages and heart rate, further highlighted these differences. Remarkably, Elite athletes exhibited a 13.1 mmol average lactate level, lower than their counterparts, and a higher average heart rate of 188.0 bpm. In terms of cognitive functions, differences were observed in various executive tasks, showcasing the nuanced impact of high-intensity exercise on cognitive abilities. In conclusion, our study provides compelling evidence that high-intensity CrossFit training positively influences executive functions. These findings are quantified through substantial variations in performance times, executive function tasks, lactate stages, and heart rates, offering critical insights into the multidimensional benefits of CrossFit training across different competitive stages.

Introducción: Las lesiones de isquiosurales tienen alta incidencia en el deporte, por lo que resulta imperativo la prevención mediante entrenamiento. Se busca y evalúa constantemente la eficacia de distintos ejercicios, sobre todo los ejercicios excéntricos por su efecto protector. Objetivo: Comparar y observar diferencias en Trabajo y Torque peak en la representación de fuerza de isquiosurales, mediante dinamometría isocinética pre y post ejecución de programas de entrenamiento excéntrico. Metodología: 2 grupos de entrenamientos aleatorios, ha ambos se les realizo evaluación isocinética para isquiosurales, a velocidades de 60°/s y 180°/s bilateral; posteriormente se realizó un entrenamiento de 6 semanas; el Grupo 1 (G1) realizó un entrenamiento de “Curl Nórdico” (CN), y el Grupo 2 (G2) un programa excéntrico (EE) excluyendo al CN, posterior al programa se reevaluaron. Resultados: Ambos entrenamientos evidenciaron diferencias significativas (p0,05). Por otra parte, ambos entrenamientos muestran grandes tamaños del efecto. No hubo diferencias significativas entre los entrenamientos al compararlos en ganancia de fuerza. Conclusión: El programa de entrenamiento curl nordico (G1) y de ejercicios excéntricos que excluyen al CN (G2) ha demostrado ser una opción viable para generar adaptaciones neuromusculares que se traducen en ganancia de fuerza excéntrica y reducción del riesgo de lesión, gracias a la optimización de las ratios funcionales.

Emergency services in sports environments are crucial to ensuring the safety of those participating. Although Rio de Janeiro boasts a large and varied number of sports facilities, little is known about the dynamics of care provided in these locations. The primary objective of this study was to analyze the emergency response data from sports environments attended by the Military Fire Brigade of the State of Rio de Janeiro (CBMERJ). Secondly, the study aimed to compare the factors associated with emergency care at sports facilities, identify the most common injury sites, infer the causes of these accidents, and observe the frequency of fatalities during sports activities. For this study, 615 data points from the first emergency rescue group (1GSE) of the Rio de Janeiro Military Fire Brigade were analyzed, divided into North (n = 215), South (n = 145), West (n = 214), and Central (n = 30) zones. The dependent variables were: gender, outcome types, care types, transport types, immobilization, care characterization, care strategy, death details, emergency occurrences, and injury distribution by region. The zones were compared using the Kruskal-Wallis test and Dunn’s post hoc analysis, with a significance level of p≤0.05. Statistical analysis revealed differences between the zones when comparing outcomes, with the northern zone showing higher values (~75%) of treated and removed victims compared to the western zone (60%). There were also differences between the zones in the type of care provided, where the northern zone showed higher values (~35%) of intermediate care compared to the western (~20%), southern (~25%), and central (%) zones. The type of transport used varied between zones, with the southern zone showing higher usage of rapid response vehicles (ASE L) than the northern and central regions. The analysis further revealed a difference in immobilization conditions, with the central zone showing a lower frequency (~20%) of immobilization, that is, a higher proportion of "other" outcomes compared to the northern (~40%), western (%), and southern (~50%) zones. Keywords: Emergency care; sports practices; injury; Fire Department.

Objectives: To compare the match running performance of male soccer players in the Brazilian A series before and after being infected with COVID-19. Methods: The sample consisted of 20 professional soccer players from Rio de Janeiro-based teams during the 2020 and 2021 seasons, pre- and post-COVID-19 infection. Match running performance data were collected using a Global positioning system (GPS), and the analysis includes average data across 1 to 17 games pre-infection and 1 to 13 games post-infection per player. Results: COVID-19-infection induced an unclear effect on the total distance traveled during the match [SWC-Factor = -1.9, 90 % CL (-4.7; 0.9)], the number of sprints at speeds over 24 km/h [SWC-Factor = 1.1, 90 % CL (-1.7; 3.9)], maximum speed reached [SWC-Factor = 0.1, 90 % CL (-2.6; 2.9)], the number of decelerations [SWC-Factor = -2.2, 90 % CL (-5.0; 0.6) ], explosive efforts [SWC-Factor = -2.4, 90 % CL (-5.1; 0.4) ], distance traveled at speeds between 0 and 7 km/h [SWC-Factor = 2.4, 90 % CL (-0.4; 5.2) ], and distance traveled at speeds between 7 and 14 km/h [SWC-Factor = -1.8, 90 % CL (-4.5; 1.0) ]. However there was a moderate and significant decrease in distance covered during high-intensity running, defined as speeds greater than 20 km/h [SWC-Factor = -4.2, 90 % CL (-7.0; -1.5) ], the number of accelerations greater than 3 m/s² [SWC-Factor = -3.6, 90 % CL (-6.4; -0.9) ], and distance traveled at speeds between 14 and 20 km/h [SWC-Factor = -3.5, 90 % CL (-6.2; -0.7) ]. The results also showed that COVID-19-infection led to a substantial decrease in minutes played during matches [SWC-Factor = -4.0, 90 % CL (-6.8; -1.3)], affecting the analysis of match variables' absolute values. Conclusion: The results suggest that players infected with COVID-19 experienced changes in match running performance, notably decreases in distance covered during high-intensity running and increases traveled at speeds between 0 and 7 km/h. Further analysis of other player populations (in other leagues) is necessary to verify these findings. Keywords: Coronavirus, Physiology, Task Performance and Analysis, Match running, External Load.

Repetitive Transcranial Magnetic Stimulation (rTMS) is a non-invasive technique used to treat and diagnose eating disorders (EDs) by targeting brain regions like the dorsolateral prefrontal cortex, which is involved in impulse control and emotion regulation. Particularly beneficial for athletes, rTMS can reduce symptoms of EDs. Therefore, this study aimed to carry out a systematic review of the scientific literature on the therapeutic or diagnostic use of rTMS in athletes and patients with EDs, with an emphasis on binge eating disorder (BED), anorexia nervosa (AN), and bulimia nervosa (BN). A literature survey was carried out in the Directory of Open Access Journals (DOAJ), Medline, Directory of Open Access Scholarly Resources (ROAD), Academic Search Premier, Wiley-Blackwell Full Collection, Nature Open Access, BioMed Central Open Access, and Cumulative Index to Nursing and Allied Health Literature (CINAHL). A total of 26 original papers published until November 21, 2021, were included. The selected studies were grouped for each respective protocol: total number of patients or athletes, sociodemographic aspects of the participants, parameters performed in rTMS: type of coil, intensity, frequency, number of pulses, stimulation site, preliminary results, and incidence of adverse effects. Recent evidence suggests a low rate of side effects with the technique and a substantial high frequency rTMS response in both the dorsolateral prefrontal cortex and the ventromedial region, especially in studies where internal comparison was performed. The great tolerance and safety of neuromodulatory treatment with rTMS encourage the application of the technique, especially in patients with refractory eating disorders. In addition to the therapeutic potential, rTMS is an essential diagnostic tool in elucidating the complex neurobiology of eating disorders. A more significant increase in publications on the subject is expected in a controlled, blind, and randomized manner, leading to a homogenization of results and generalization of its potential use. Keywords: Eating disorders, Neurology, Neuromodulation, Psychology, Psychiatry, Noninvasive brain stimulation.

This study compared acute measures of concussion in Olympic boxers undergoing a combat. This is a case-control study where participants were measured in two conditions: a) using headgear (HG) and b) without using headgear (NHG). Thus, 14 athletes (24.9±5.1 yrs.; 77.1±13.9 kg; 1.7±0.1 m; 14.4±6.4 % body fat) completed this protocol. Tests were carried out before and after the combat (3 rounds of 3' with 1' interval) as indicators of concussion (BtrackS concussion test, automatic and controlled executive function, direct and indirect memory). A technical-tactical analysis protocol was also applied to verify the effect of HG on the actions during the combat. The HG condition showed better performance on the BtrackS concussion test (30.3±11.3 vs. 38.5±12.2; p=0.039), automatic executive function (38.0±6.0 vs. 50.4±11.4; p=0.014), and controlled (55.3±8.1 vs. 76.4±11.5; p=0.016). There was a significant difference in the number of punches connected to the head (38.5±12.0 vs. 51.1±14.7 for HG and NHG respectively; p=0.047). Based on our aims and the results obtained, our data support the acute protective effect of using HG in amateur Olympic male boxing against the concussion indicators. Keywords: Combat sports, Boxing, Olympic Games, Brain concussion, Cognition, Sport rules

Sprint performance is a critical factor in soccer. While previous studies have extensively explored the biomechanical, physiological, and metabolic determinants of sprinting, the impact of anthropometric variables in team sports contexts, especially soccer, remains underexplored. This study aims to investigate the influence of anthropometric and mechanical variables on sprint performance in young soccer players. Fifty-eight young soccer players were evaluated in anthropometry and a 30-meter (m) sprint using radar technology. Split times in 5, 15, and 30 m were determined, in addition to the assessment of the force-velocity profile proposed by Morin and Samozino. Results: Key anthropometric variables associated with improved sprint performance included lower-limb muscle mass at distances 5 and 15 m (R2 = 0.08 and R2 = 0.09, respectively, both with small effects). Additionally, body composition, particularly a lower % body fat, was crucial across all sprint distances (ES: large). Among the mechanical variables, max power (R2 = 0.997, ES: large) and maximum velocity (R2 = 0.553, ES: large) are the mechanical variables that were most strongly associated with sprint performance over distances greater than 30 m. Soccer coaches, athletic trainers, and strength and conditioning specialists working with young athletes can apply the findings of this study to their training programming.

Objective: A systematized review was carried out to identify the studies that during the last ten years have used isokinetic equipment in sports in which the upper extremity is the basis of its practice, to provide an updated and detailed view of its use, methodologies and the variables used to express their results. Methods: A systematized search of 10 years of information was carried out, according to the PRISMA process, in the databases: Scopus, Web of Science, Pubmed, CINAHL, using combined terms: «isokinetic» «upper extremity», «upper limb», « sport», «exercises», «upper extremity». Results: 9406 articles were identified in the databases for review, of which only 46 were selected based on inclusion criteria. Among the sports evaluated, 25 articles correspond to sports with overhead throws (basketball, volleyball, baseball, handball, among others), followed by Paralympic sports with six articles (basketball and volleyball). Sports such as swimming, judo, weightlifting, water polo, or combined sports complete the list. The shoulder rotator muscles were the most evaluated and the concentric-concentric modality was the most used. The variable moment is the most reported, but the evaluation methodologies and selected speeds differ significantly between studies. Conclusion: The methodologies used are varied (i.e., selection of speed, type of muscular contraction, positioning, and dominance), and their selection was not always oriented toward the functionality of sports practice. In addition, it was observed that some studies needed to specify the isokinetic modality used, leaving a gap in relevant information within the study methods and affecting their future replicability. Keywords: Isokinetic evaluation; Isokinetic; upper extremity sports; upper limb.

Background: Speed training with resisted sprints has been shown to positively affect neuromuscular performance in soccer players. Various loads, ranging from 10% to 120% of body mass, have demonstrated performance improvements across the spectrum. However, the impact of sprint distance with optimal load on these adaptive responses has yet to be thoroughly described. Objective. To analyze the influence of sprint distance in resisted sprints on muscle performance in young soccer players. Methods. This quantitative study utilized a pre-post experimental design. The sample consisted of 24 young soccer players (15.3 ± 0.68 years; 61.4 ± 7.08 kg; 1.60 ± 0.06 m) randomized into three groups (10, 20, and 30 m) and subjected to 12 sessions of resisted sprint training over six weeks. The volume was homogenized across groups, with a total distance of 120 m for each. The intervention’s effect was analyzed through performance in the isometric mid-thigh pull (IMTP), countermovement jump (CMJ), modified 505 agility test (505 m), and linear sprint tests. Differences were analyzed using a mixed ANOVA, incorporating a between-subjects factor (training group) and a within-subjects factor (pre- and post-intervention). Results. Time-dependent differences were observed in all groups for peak force (PF) (p < 0.001; η2p = 0.62), time to PF (TPF) (p < 0.001; η2p = 0.53), impulse at 50 (p < 0.001; η2p = 0.57), 100 (p < 0.001; η2p = 0.60), and 200 ms (p < 0.001; η2p = 0.67) in IMTP; jump height by impulse-momentum (p < 0.001; η2p = 0.64), rate of force development (p = 0.04; η2p = 0.14), yielding impulse (p < 0.001; η2p = 0.49), and concentric impulse (p = 0.01; η2p = 0.19) in CMJ; time (p < 0.001; η2p = 0.46) in 505 m; and average speed in linear sprint (p = 0.003; η2p = 0.36), with moderate to large effect sizes, regardless of the distance covered. No differences were observed for the interaction between the time* and group or between groups. Conclusion. Performance improvements were independent of the sprint distance, with no differences between training groups. Distances between 10 and 30 m may enhance muscle performance in young soccer players.

Assessing the reliability of measurement instruments and equipment is essential to ensure the accurate tracking of athletes over extended periods, minimizing the measurement errors caused by chance or other factors. However, a less common but equally important analysis is the verification of inter-measurement agreement, which complements the reliability results. Purpose: To evaluate the intra- and inter-test reliability of an isometric hip adduction strength and asymmetries test in professional soccer players. Methods: Twenty-three professional male soccer players were evaluated on two occasions, 1 week apart. The force signal was collected using force plates (Pasco PS-2141), and the data processing was performed using Matlab software (R2023a, MathWorks, Natick, MA, USA). The peak force, interval RFD, peak RFD, peak force asymmetry and RFD were analyzed. Intraclass correlation coefficients (ICCs) and coefficients of variation (CV) were calculated to corroborate the intra- and inter-test reliability. In addition, the degree of agreement of the asymmetries was corroborated through the kappa index. Results: The peak force demonstrated an acceptable absolute reliability (CV < 10%) for the intra-test and test–retest condition, an excellent relative intra-test reliability and a good to moderate reliability for the test–retest reliability. However, the peak force asymmetry showed a moderate test–retest reliability and agreement. For the intra-test condition, the RFD variables demonstrate a moderate to excellent relative reliability; however, all demonstrate unacceptable absolute reliability (CV > 10%) in at least one of the evaluation sessions. A moderate to poor test–retest reliability and unacceptable absolute reliability were observed for all the RFD variables. Conclusions: The peak force is the variable with the highest intra- and inter-test reliability, so its use is recommended to longitudinally assess the maximum strength of the adductors in professional soccer players, but not the asymmetry orientation of the peak force. The RFD variables should be interpreted with caution due to their inconsistent reliability, and it is necessary to improve the methods used to achieve adequate reliability.

Aging is habitually related to modifications in the peripheral, central nervous and musculoskeletal systems. These modifications are frequently associated with mobility complications. It is currently considered that the spatiotemporal gait parameters (SGP) may be good functional indicators of the severity of knee osteoarthritis (KOA). Objective: to compare the SGP in middle-age and older women with different radiographic KOA diagnosis. Methods and materials: For this, ninety-nine (99) female participants (age: 61.0±3.0 years; body mass: 72.9±13.4 kg; height: 1.5±0.1 m; BMI: 31.2±5.7 Kg/m2) were enrolled in a cross-sectional design. All participants were classified according to the Kellgren-Lawrence radiological scale (None n=15; Doubtful n=24; Minimal n=22; Moderate n=20 and Severe n=18). All participants performed a 25-m Walk test for which the SGP was measured (cadence, duration of monopodal support phase, and stride length). Results: No differences were observed in any SGP measures (cadence, p=0.57; monopodal support phase, p=0.65; and stride length, p=0.22). Conclusion: Our results showed that there is no agreement between the SGP and radiographic KOA diagnosis. Keywords: gait analysis, knee osteoarthritis, musculoskeletal diseases, early diagnosis

This study aimed to measure the associative and predictive strength of biomechanical variables of the countermovement jump (CMJ) and squat jump (SJ), and performance of the bandal-chagi kick performed with the dominant (D) rear lower limb in elite Taekwondo Athletes. For this, a total of 27 international level athletes (15 males and 12 females) performed the CMJ and SJ on two force platforms. The bandal-chagi was monitored using a motion capture system (VICON). The main results indicated that non-dominant (ND) Stiffness for the CMJ showed predictive power alone (p=0.048) or in combination with eccentric breaking rating of force development (RFD) (p=0.031) for total hip angular speed. Takeoff peak force/BM for the SJ predicted total time (p=0.002). Concentric RFD/BM predicted total linear foot acceleration, either alone (p=0.001) or with vertical speed at takeoff (p=0.042). The total hip angular acceleration predictor was takeoff peak force D alone (p=0.019) or in combination with peak power/BM (p=0.041). In conclusion, CMJ and SJ tests showed specific associations with TKD kick performance. These analyses in this study indicated that they are good predictors for TKD athletes, producing results consistent with the participants’ levels. Keywords: Martial arts, Biomechanical Phenomena, Time-motion studies, Kinanthropometry, Motion Capture.

RESUMEN El objetivo de este estudio fue comprobar el efecto del entrenamiento de las figuras a través de ejercicios especiales durante el período preparatorio. Las participantes fueron 13 nadadoras artísticas con edades de 9 a 12 años. Se realizó un pre-experimento pretest-postest para un solo grupo y se aplicó la prueba no paramétrica de Wilcoxon. En cuanto a los resultados del postest con respecto al pretest en la figura pierna de ballet recta, en los indicadores diseño Z (-2,536b) y control Z (-2,539b) se muestra un mayor efecto del entrenamiento y fue de igual manera en la figura barracuda Z (-2,536b). Se puede afirmar, que la propuesta resalta su funcionabilidad.

Several studies have shown that force application is influenced by different neuromuscular mechanisms depending on the time of force application analysis in isometric knee extension test (IKE), and a countermovement jump (CMJ) has contributions from knee extension, so some CMJ variables could be indicators of such mechanisms. Purpose: The aim of this study was to determine the level of relationship of variables of IKE and bilateral CMJ tests. Methods: Male college soccer players (n = 25; corporal mass = 72 ± 8 kg; height = 171 ± 5 cm; age = 22 ± 2 years) performed the IKE at two angles (60° and 75°) on an isokinetic machine and the CMJ on two uniaxial force platforms. To determine the level of relationship, Pearson’s correlation coefficient was analyzed between the test variables. Results: Trivial to moderate correlations (r = −0.45 to 0.62; p < 0.05) were found between CMJ variables and IKE in both knee angles (60° and 75°); Conclusions: The variables of IKE have a trivial to moderate correlation with the variables of CMJ, so the variables of CMJ could not be considered interchangeably with those of IKE and therefore considered indicators of neuromuscular mechanisms isolated from the knee extensor function. Longitudinal design (fatigue or training protocols) should be realized to corroborate these results.

Variable resistance training has been widely used in athletic preparation. Objectives: To analyze the use of currents (VRT) and the traditional method (TRAD) on speed, power and temperature in a training session. Methods: Fourteen paralympic powerlifting (PP) athletes took part over three weeks. In week 1, familiarization and 1RM tests took place, and, in weeks 2 and 3, pre- and post-training took place, where the propulsive mean velocity and power and temperatures were assessed before and after, at 24 h and 48 h. Results: There was a difference in the sternal pectoral temperatures before and after VRT (p = 0.040) and at 48 h for TRAD and VRT (p = 0.018); in the clavicular pectoralis before and after VRT and TRAD (p = 0.003); in the anterior deltoid after and at 48 h for TRAD and VRT (p = 0.026 and p = 0.017); and in the triceps after and at 24 h and 48 h between TRAD and VRT (p = 0.005). In the training series, the MPV was significant in TRAD between Set1 and Set5 (p = 0.003), in training (VRT) between Set1 and Set5 (p = 0.001) and in Set5 between the methods (p = 0.047). For power, there was a difference between Set1 and 5 in TRAD (p = 0.016) and VRT (p = 0.002). Conclusion: We conclude that training with currents (VRT) promoted greater muscle fatigue when compared to traditional training.

This study review and analyze studies that measured the effect of combined strength/power warmup (COMB) versus traditional (TRAD) on the post-activation performance enhancement (PAPE) of swimmers. For this, we performed a systematic review was carried out with meta-analysis based on descriptors related to PAPE in swimming. A total of 138 articles were identified, of which 15 were selected. Comparisons between the COMB condition and the TRAD warm-up were performed for the following set of variables: a) power in 50- and 100-meter events, b) start performance, c) test time of 50- and 100- meters, and d) instantaneous speed in 50-meters events. The data extracted from the studies showed acceptable homogeneity (I²=0.000). When we observed the confidence intervals, it was verified that there were no differences between the COMB condition and the TRAD for power in 50 and 100 m events (Hedges g'=-0.12; 95%CI=-0.376; 0.136; p=0.357); time in 50- and 100-meter races (Hedges g'=-0.139; 95%CI=-0.314; 0.036; p=0.118); start performance (Hedges g'=-0.313; 95%CI =-0.643; 0.018; p=0.064). The COMB condition had an ergogenic effect on instantaneous speed in the 50 m event (Hedges g'=-0.282; 95%CI=-0.402; -0.162; p≤0.001). In conclusion, the present meta-analysis concluded that the COMB intervention does not exert an ergogenic effect on the performance of swimmers for the set of analyzed variables, except for instantaneous speed in 50 m events. Future studies may compare other forms of warmup versus the TRAD. Keywords: Warm-up exercise; Musculoskeletal and Neural Physiological Phenomena; swimming; athletic performance.

Objetivo: Analizar la asociación entre la aptitud física aeróbica y el metabolismo glucolítico en jugadores profesionales varones adultos chilenos. Como objetivo secundario, examinar las diferencias entre posiciones de juego. Métodos: La muestra corresponde a 31 futbolistas profesionales adultos pertenecientes a un club de Primera B de Chile. Se determinó la aptitud aeróbica a través de la prueba Yo-Yo de resistencia intermitente nivel I. Se obtuvo una muestra de lactato posterior a su finalización, con el propósito de analizar la implicancia del metabolismo glucolítico. Se realizó la prueba de Pearson para identificar las asociaciones entre variables y la prueba ANOVA de un factor para analizar las diferencias entre posiciones de juego. Resultados: No existe relación entre la aptitud aeróbica y el metabolismo glucolítico (r=0.165 y p=0.375). Del mismo modo no se presentan diferencias entre posiciones para la aptitud aeróbica (p=0.64) y producción de lactato (p=0.75). Conclusión: El rendimiento en esfuerzos dependientes de oxígeno no se relaciona con la capacidad glucolítica para esta muestra de futbolista profesionales, por tanto, no es posible proyectar influencias entre las variables, así como tampoco en función de la posición en el campo de juego. Palabras clave: Fútbol, rendimiento físico aeróbico, metabolismo glucolítico, lactato. Abstract. Objective: Analyze the association between aerobic physical fitness and glycolytic metabolism in adult male professional Chilean soccer players. As a secondary objective, examine differences between playing positions. Methods: The sample consists of 31 adult professional footballers from a Chilean Primera B club. Aerobic fitness was determined through the Yo-Yo intermittent endurance level I test. A lactate sample was obtained after its completion to analyze the implication of glycolytic metabolism. The Pearson test was performed to identify associations between variables, and the one-way ANOVA test was conducted to analyze differences between playing positions. Results: There is no relationship between aerobic fitness and glycolytic metabolism (r=0.165 and p=0.375). Similarly, there are no differences between positions for aerobic fitness (p=0.64) and lactate production (p=0.75). Conclusion: The performance in oxygen-dependent efforts is not related to glycolytic capacity for this sample of professional footballers. Therefore, it is not possible to project influences between the variables, nor based on the playing position. Keywords: Soccer, aerobic physical fitness, glycolytic metabolism, lactate.

A systematic review with meta-analysis on the dynamic strength and muscle power in elite and non-elite Brazilian jiu-jitsu (BJJ) athletes is essential to provide a comprehensive and quantitative evaluation of the physical attributes critical for performance, allowing for a better understanding of the training needs and physical characteristics that distinguish different levels of athletes in this sport. Therefore, this study endeavors to comprehensively synthesize existing literature on muscle strength and power in the context of BJJ, making a comparative analysis between elite and non-elite athletes. The research was conducted up to April 20, 2022, employing the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) protocol to systematically search electronic databases using the keywords: "Brazilian Jiu-jitsu" or "BJJ" or "Jiu-jitsu" and "power" or "muscle power" or "physical fitness" or "muscle strength" or "strength." Following a rigorous selection process, 26 articles were included in the systematic review. Subsequently, the GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) tool was employed for evidence assessment. The primary assessments of dynamic strength encompassed protocols involving the Bench press, squat, and pull-up-gi. In the context of muscle power, the meta-analysis considered parameters such as the countermovement jump (CMJ), standing long jump, and variables derived from jump power assessed on the force platform, including Peak velocity, peak power, mean power, and maximum force. The data showed a substantial effect size for strength [1.012 (p≤0.0001)] and a moderate effect size for power [0.619 (p≤0.0001)], indicating superior performance among elite athletes compared to their non-elite counterparts. Although power is predominant in most BJJ actions, strength emerges as a crucial element distinguishing elite from non-elite athletes in this sport. This realization carries significant implications for training and injury prevention, as both strength and power necessitate specialized training to enhance performance in the sport. Keywords: Physical Fitness, Martial Arts, Sport Physiology, Musculoskeletal and Neural Physiological Phenomena, Judo

Antecedentes. La participación de las mujeres en el fútbol se ha incrementado exponencialmente en los últimos años, por lo que integrar antecedentes basados en la evidencia en esta población, permite una mejor compresión y análisis del desempeño deportivo de atletas femeninas. Objetivo. Determinar el nivel de asociación entre los indicadores de composición corporal y el rendimiento en test 30-15 IFT en futbolistas mujeres de primera división. Métodos. Participaron 29 jugadoras profesionales de un equipo de primera división de Chile. Se evaluó el test 30-15, se analizó la velocidad final alcanzada (VIFT) y se estimó el consumo máximo de oxígeno (VO2máx). La composición corporal (CC) fue estimada a través de antropometría y se analizó la talla, masa corporal, índice de masa corporal (IMC), masa adiposa absoluta (MA) y relativa (PMA), masa muscular absoluta (MM) y relativa (PMM) y sumatoria de 6 pliegues (S6P). Para analizar el nivel de asociación, se utilizó el coeficiente de correlación de Pearson (r) con un alfa de 0.05. Resultados. Se encontraron correlaciones negativas débiles entre MA con VIFT (r = -0.384 y p = 0.04) y VO2máx (r = -0.375 y p = 0.45); correlaciones negativas moderadas entre S6P con VIFT (r = -0.476 y p = 0.009) y VO2máx (r=0.454 y p=0.013); correlaciones negativas moderadas entre IMC con VIFT (r = 0.401 y p = 0.031) y VO2máx (r = -0.379 y p = 0.043). No se hallaron correlaciones entre MM y PMM con VIFT o VO2máx. Conclusión. Es posible concluir que el rendimiento en el 30-15IFT presenta asociación con la composición corporal, específicamente con la MA, S6P e IMC en las jugadoras evaluadas.

In the quest to understand the dynamics of female Brazilian Jiu-Jitsu (BJJ) combats, this research delves into the world of winning and losing. By comparing time-motion analysis based on different outcomes, our objective was to unveil the movement patterns of victory. Our sample included 209 winning (W) versus 209 losing (L) female international BJJ combats, presenting a comprehensive picture of the combat landscape. Through time-motion analysis, we explored various BJJ combat phases, such as approach, gripping, transition, side control, mounting, attack, defense, low-intensity movement, and total time. The statistical results highlight significant differences between winners and losers in key aspects of the combats. Notably, side control (W= 47.7 [27.8; 96.5]s vs. L= 27.3 [20.3; 41.9]s), mount (W= 40.0 [16.6; 85.9]s vs. L= 15.9 [6.1; 25.6]s), attack (W= 50.1 [28.6; 86.7]s vs. L= 16.6 [7.7; 35.7]s), defense (W= 14.6 [6.6; 38.2]s vs. L= 38.8 [17.7; 77.0]s), and low-intensity movement (W= 55.9 [23.4; 132.2]s vs. L= 111.5 [58.7; 225.6]s) revealed differences between the winners and losers. The implications extend to sports psychology and judo training, providing knowledge for enhancing performance, optimizing training programs, and making strategic decisions during combat. Keywords: sports psychology, technical-tactical analysis, task performance and analysis, judo, martial arts.

Contexto: El análisis biomecánico de técnicas deportivas facilita la optimización del rendimiento, promueve una correcta ejecución técnica y ayuda a identificar factores de riesgos de lesión. Objetivo: Proponer un modelo biomecánico de la técnica de pecho en futvoley, señalando indicadores cinemáticos para su evaluación. Métodos: Se realizó un estudio de caso con alcance descriptivo a través de un participante con 20 años de experiencia en futvoley. Se capturó la técnica de pecho de futvoley a través de videofotogrametría con una cámara de alta velocidad (240 Hz). El análisis fue realizado con el software de análisis deportivo Kinovea®. Se determinaron las fases de la técnica deportiva a través de una propuesta utilizada previamente: a) el objetivo general de rendimiento de la técnica (OGR); b) los propósitos mecánicos (PM) de cada fase, el cual hace referencia a la principal característica mecánica por lograr en cada fase; y c) objetivos biomecánicos (OB), correspondientes a los indicadores cinemáticos (ICm) e indicadores cinéticos (ICn) derivados del PM. Resultados: la técnica se dividió en las fases de Aproximación, Preparación, Impulso y Seguimiento. En cada fase se describió el OGR de la técnica y los PM y OB. Aplicaciones prácticas: La propuesta biomecánica basada en OGR, PM e ICm permite la comprensión de esta técnica deportiva, favoreciendo su análisis, enseñanza y optimización del rendimiento. Palabras clave: Futvolei, Cinemática, Biomecánica. Abstract. Context: The biomechanical analysis of sports techniques facilitates performance optimization, promotes proper technical execution, and helps to identify injury risk factors. Objective: To propose a biomechanical model of the chest technique in footvolley, indicating kinematic indicators for its evaluation. Methods: A case study with a descriptive scope was conducted through a participant with 20 years of experience in footvolley. The chest technique in footvolley was captured through video-photogrammetry using a high-speed camera (240 Hz). The analysis was carried out using the Kinovea® sports analysis software. The phases of the sports technique were determined through a previously used proposal: a) The general performance objective of the technique (GPO); b) The mechanical purposes (MP) of each phase, which refers to the main mechanical characteristic to be achieved in each phase; c) Biomechanical objectives (BO), corresponding to the kinematic (KI) and kinetic indicators (KnI) derived from the MP. Results: The technique was divided into the phases of Approach, Preparation, Impulse, and Follow-up. In each phase, the GPO of the technique and the MPs and BOs were described. Practical applications: The biomechanical proposal based on GPO, MP, and KI allows for the understanding of this sports technique, facilitating its analysis, teaching, and performance optimization. Keywords: Footvolley, Kinematics, Biomechanics.

Aims: To evaluate peppermint essential oil (PEO) inhalation's effect on young soccer athletes' motor performance. Methods: A randomized crossover design was used to test the effect of the PEO. Eleven U-17 soccer players were evaluated into two conditions (PEO and Placebo – PLA). The players were tested in squat jump and countermovement jump and inhaled PEO or PLA and 10 min later performed the physical tests again. A mixed ANOVA was performed to test the hypotheses. Results: Main effects were found for the time in jumping height in the CMJ (p = 0.037). No main and interaction effects were found in the SJ variables. Conclusion: From the results, decrease CMJ performance acutely, both conditions presented decrease in JH, but based in effect size, PLA decrease is higher (more sample size for corroborate this) possibly due to improvements in the eccentric yielding sub-phase, where mentioned phase could be reflecting neural changes (required experimental verification). The PEO could be the interest in trainers for use before of match or in the half-time for minimize the decreased of physical performance by the rest.

Coaches and psychologists can use time-motion analysis to elaborate specific interventions for female BJJ athletes, increasing specific training context and reducing unnecessary psychological and physical demands and injuries. Therefore, the present study aimed to analyze high-level BJJ female athletes in the 2020 Pan-American Games by comparing the weight categories on the time-motion analysis. The time-motion analysis (i.e., approach, gripping, attack, defensive actions, transition, mounting, guard, side control, and submissions) of 422 high-level female BJJ combats was divided and compared by weight category as follows: Rooster (n = 8), Light Feather (n = 18), Feather (n = 122), Light (n = 84), Middle (n = 74), Medium Heavy (n = 44), Heavy (n = 36), Super Heavy (n = 36), using p ≤ 0.05. The main results indicated that the Super heavyweight category [3.1 (5.8;119.9) s] had a shorter gripping time than other weight categories, p ≤ 0.05. In contrast, roosters [7.2 (3.5;64.6) s] had longer gripping, transition [14.0 (4.8;29.6) s], and attack time [76.2 (27.7, 93.2)] than the light feather, middlers, and heavier weight categories, p ≤ 0.05. These findings should be considered for the psychological interventions and training prescription.

Objetivo: Proponer y describir el modelo cinemático de pateo con empeine en jugadores profesionales de futsal de Chile. Método: Se elaboró el modelo biomecánico de la ejecución de gesto técnico de pateo con empeine en futsal, a través de una búsqueda bibliográfica y se realizó un análisis cinemático de la ejecución en jugadores profesionales varones de futsal (n = 12, Edad 21 ±2,83 años, masa corporal 75,5 ±12,01 kg., estatura 1,74 ±0,05 m.) quienes compiten en el Campeonato de Futsal ANFP de Chile. La evaluación del remate fue realizada en una cancha de futsal oficial (Estándar FIFA). El balón fue situado en el punto penal, y los participantes realizaron 2 intentos cada uno. Las variables cinemáticas seleccionadas fueron las posiciones y velocidades angulares de rodilla y tobillo, para ambas piernas, y en cada fase del remate. Para la aplicación del análisis, se utilizó el sistema de captura de movimiento VICON®. Los marcadores fueron situados en ambos miembros inferiores según modelo Plug-In Gait™ Standard Lower Body. Resultados: A través de la búsqueda bibliográfica se generó y analizó un modelo de 4 fases: Unipodal, Balance, Contacto y Post Impacto. Se describió la cinemática (Posición [rad] y velocidad angular [rad/s] de rodilla y tobillo de las 4 fases. Conclusiones: La búsqueda bibliográfica dio como resultado para la investigación cualitativa, la modificación de un modelo biomecánico existente, generando de este modo, el diseño del modelo de pateo con empeine en futsal y describió la posición y velocidad angular promedio de cada fase. Palabras clave: biomecánica, deportes, destreza motora, rendimiento atlético, revisión Abstract. Objective: To propose and describe the kinematic model of instep kicking in professional futsal players in Chile. Methods: A biomechanical model of the execution of the technical gesture of instep kicking in futsal was developed through a literature search and a kinematic analysis of the execution was performed in professional male futsal players (n = 12, age 21 ±2.83 years, body mass 75.5 ±12.01 kg, height 1.74 ±0.05 m.) who compete in the ANFP Futsal Championship of Chile. The evaluation of the shot was performed in an official futsal court (FIFA Standard). The ball was placed on the penalty spot, and the participants made 2 attempts each. The kinematic variables selected were the positions and angular velocities of the knee and ankle, for both legs, and in each phase of the shot. For the application of the analysis, the VICON® motion capture system was used. The markers were placed on both lower limbs according to the Plug-In Gait™ Standard Lower Body model. Results: Through the literature search, a 4-phase model was generated and analyzed: Unipodal, Balance, Contact and Post Impact. The kinematics (Position [rad] and angular velocity [rad/s] of knee and ankle of the 4 phases were described. Conclusions: The literature search resulted for the qualitative research, the modification of an existing biomechanical model, thus generating, the design of the instep kicking model in futsal and described the position and average angular velocity of each phase. Keywords: biomechanics, sports, motor skills, athletic performance, review

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.

Maximal oxygen consumption (V̇O2max), physiological thresholds, and hemoglobin mass are strong predictors of endurance performance. High values of V̇O2max, maximal aerobic power (MAP), and power output at anaerobic thresholds are key variables in elite rowers. Endurance athletes often use altitude training as a strategy to improve performance. However, no clear evidence exists that training at natural altitude enhances sea-level performance in elite rowers. This study aimed to evaluate the effect of altitude training on rowing-performance parameters at sea level. The study was conducted on eleven rowers (Six females, five males) from the Chilean National Team during a 3-week moderate altitude training (∼2,900 m. a.s.l.) under the live high-train high (LHTH) model. It included a rowing ergometer maximal incremental test and blood analysis (pre and post-altitude). Gas exchange analysis was performed to measure V̇O2max, ventilatory thresholds (VTs) and rowing economy/efficiency (ECR/GE%). LHTL training improves performance-related variables at sea level (V̇Emax: 3.3% (95% CI, 1.2–5.5); hemoglobin concentration ([Hb]): 4.3% (95% CI, 1.7–6.9); hematocrit (%): 4.5% (95% CI, 0.9–8.2); RBC (red blood cells) count: 5.3% (95% CI, 2.3–8.2); power at VT2: 6.9% (95% CI, 1.7–12.1), V̇EVT2: 6.4% (95% CI, 0.4–12.4); power at VT1: 7.3% (95% CI, 1.3–13.3), V̇EVT1: 8.7% (95% CI, 1.6–15.8)) and economy/efficiency-related variables (ECRVT2: 5.3% (95% CI, −0.6 to −10.0); GE(%): 5.8% (95% CI, 0.8–10.7)). The LHTH training decreased breathing economy at MAP (−2.8% (95% CI, 0.1–5.6)), pVT2 (−9.3% (95% CI, −5.9 to −12.7)), and pVT1 (−9.3% (95% CI, −4.1 to −14.4)). Non-significant changes were found for V̇O2max and MAP. This study describes the effects of a 3-week moderate altitude (LHTH training) on performance and economy/efficiency-related variables in elite rowers, suggesting that it is an excellent option to induce positive adaptations related to endurance performance.

Eccentric resistance training that focuses on the lengthening phase of muscle actions has gained attention for its potential to enhance muscle strength, power, and performance (among others). This review presents a methodological proposal for classifying eccentric exercises based on complexity, objectives, methods, and intensity. We discuss the rationale and physiological implications of eccentric training, considering its benefits and risks. The proposed classification system considers exercise complexity and categorizing exercises by technical requirements and joint involvement, accommodating various skill levels. Additionally, training objectives are addressed, including (i) Sports Rehabilitation and Return To Sport, (ii) Muscle Development, (iii) Injury Prevention, (iv) Special Populations, and (v) Sporting Performance, proposing exercise selection with desired outcomes. The review also highlights various eccentric training methods, such as tempo, isoinertial, plyometrics, and moderate eccentric load, each with different benefits. The classification system also integrates intensity levels, allowing for progressive overload and individualized adjustments. This methodological proposal provides a framework for organizing eccentric resistance training programs, facilitating exercise selection, program design, and progression. Furthermore, it assists trainers, coaches, and professionals in optimizing eccentric training’s benefits, promoting advancements in research and practical application. In conclusion, this methodological proposal offers a systematic approach for classifying eccentric exercises based on complexity, objectives, methods, and intensity. It enhances exercise selection, program design, and progression in eccentric resistance training according to training objectives and desired outcomes.

Este artículo presenta una visión propositiva de la bibliografía actual sobre la técnica de push de empuje desde la biomecánica. El objetivo de la investigación fue describir la técnica deportiva del push de empuje en el hockey sobre césped, con el fin de proponer bases para su análisis biomecánico a través de la determinación de OGR, PM y OB. Se revisaron las siguientes bases de datos; Pubmed, Google Académico y ScienceDirect, para obtener artículos seleccionados desde 2000-2020. Se utilizó la metodología PRISMA®; se incluyeron artículos; (i) estudios centrados en el hockey sobre césped (ii) artículos que hagan referencia al gesto del empuje y (iii) estudios escritos tanto en inglés, como en español. Los artículos incluidos fueron 5, posteriormente se elaboró un modelo técnico compuesto por tres fases: acomodación, aceleración y seguimiento, donde cada fase presento sus propósitos mecánicos y objetivos biomecánicos, entregando una estrategia innovadora para el análisis de la técnica deportiva con un enfoque desde el deporte hacia la biomecánica deportiva. Abstract. The article presents a propositional point view of the current bibliography on the push technique from biomechanics. The aim of this research was to describe the push sports technique in field hockey, in order to propose bases for its biomechanical analysis through the determination of OGR, PM and OB. The following databases were reviewed; Pubmed, Google Scholar and ScienceDirect, to obtain selected articles from 2000-2020. The PRISMA® methodology was used; articles were included; (i) studies focused on field hockey (ii) articles that refer to the push gesture and (iii) studies written in both English and Spanish. The articles included were 5, subsequently a technical model was elaborated composed of three phases: accommodation, acceleration and monitoring, where each phase presented its mechanical purposes and biomechanical objectives, delivering an innovative strategy for the analysis of sports technique with a focus from the sport towards sports biomechanics.

Motor learning generates synaptic neural connections that favour the motor environment and, also, various processes where our cognitive and executive functions intervene. Therefore, it is essential to know the different contributions that come from neuroscience linked to motor learning in a child. This study aimed to determine the fundamental contributions of neuroscience to motor learning in children. The methodology included a qualitative systematic review in the PubMed, Medline and Scopus databases. Of 479 related documents, 24 papers achieved the inclusion criteria (the learning mechanisms of motor skills and the different approaches to achieving meaningful learning). They were selected using the data collection methodology indicated by PRISMA®. The main results indicated that learning occurs based on experiences (cognitive, perceptual, motor, linguistic, neuronal, organic and cultural) and requires processes of adaptation, stabilization, and maturation of brain synchronization of vestibular, perceptual and visual processes. Children who receive motor intervention improve sustained attention, working memory, problem-solving and planning capacity. Motor and cognitive development are favoured by instructions as an essential tool. The implicit instructions present a higher benefit for children with lower motor skills.

This study measured the peak force (PF) in cadet inline speed skaters (ISS) and verified the physical measures that determine athletes' performance on the Isometric Mid-Thigh Pull Test (IMTP) through a multivariate regression and discriminant canonical analysis. A total of 36 high-performance male (n= 18; age= 17.4± 1.21 years; body mass= 65.1± 6.18 kg; height= 168.6± 5.1 cm) and female (n= 18; age= 17.4± 1.23 years; body mass= 55.5± 4.4 kg; height= 158.6± 5.2 cm) athletes were measured two times (with a 3-day interval). All participants performed the IMTP and sit-and-reach (SR) tests, and an evaluator performed anthropometric circumference measurements on their thighs and calves. The main results indicated that males showed a higher PF on the test (m= 59.0± 3.9 N/kg vs. f= 50.4± 5.8 N/kg; p≤ 0.001) and retest (m= 59.1± 4.2 N/kg vs. f= 51.9± 6.6 N/kg; p≤ 0.001). In the first, thigh circumference (X2= 29.01, p≤ 0.001, R2= 0.74) had an overall 91.7% prediction. The second model included using the SR and thigh circumference (X2= 49.91, p≤ 0.001, R2= 1.0) showed an overall prediction of 100.0%. The thigh circumference matrix showed better predictive power for (coefficient= 7.158) male and female IMTP performance. In conclusion, despite the gender differences, the thigh circumference is a good predictor for PF in cadet ISS athletes.

Aedo-Muñoz, E., Tamayo Contreras, V., Rojas Reyes, C., Hernández Wimmer, C., Brito, C., Miarka, B., Arghoty Bucheli, R., Dal Bello, F y Herrera Valenzuela, T. (2020). Potencia y actividad electromiográfica en voleibolistas universitarios. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 18(1), 1-14. El propósito del estudio fue determinar la potencia relativa del miembro inferior y actividad electromiográfica de superficie (EMGs) del glúteo mayor (GM), vasto medial (VM), vasto lateral (VL) y gastrocnemio lateral (GASLAT), durante un salto contramovimiento (CMJ) y un salto Abalakov (ABK). Un total de 24 voleibolistas universitarios se dividieron en dos grupos iguales asignados por el nivel de competencia: el grupo 1 (G1), compuesto por voleibolistas de 1ª división universitaria y el grupo 2 (G2), compuesto por voleibolistas de 2ª división universitaria. Cada uno fue sometido a dos evaluaciones simultáneas de potencia y EMGs. Para la potencia se utilizó un sistema de grabación en 2D, por medio de un seguimiento del trocánter mayor con una cámara de 250 fps. Esta grabación se sometió a una medición por medio de software (Tracker), para obtener los valores de potencia absoluta. La EMGs se realizó por medio de un electromiógrafo Delsys Trigno en los músculos GM, VM, VL y GASLAT. Se presentaron diferencias significativas en %PeakRMS del VL (G1=65.210.2; G2=54.0±11.7 %PeakRMS; p0.05) y ABK (p>0.05).

Este trabajo analizó la relación entre la posición de flexión mantenida durante la práctica de ciclismo y la posible relación con dolor lumbar. Se llevó a cabo una revisión sistematizada a través del proceso PRISMA® entre 2015-2020, en las bases de datos PubMed, PEDro, Scopus y Web of Science, empleando los términos; “cycling”, “cyclist”, “position”, “positioning”, “overuse injury”, “spinal biomechanic”, “lower back”, “lower back pain”. Se seleccionaron 5 artículos que cumplieron con todos los criterios de inclusión. Los artículos seleccionados mostraron cambios en la inclinación pélvica, ángulos de flexión de tronco en tomadas medias y bajas del manillar de bicicleta de ruta y bicicleta de montaña, variaciones del asiento más arriba o atrás de la posición adecuada según longitud entrepiernas, la posición de rodilla 40º y tronco 35º de manera simultánea cuando el pedal está en 180º, mientras que en posición anatómica se describieron; ángulo máximo de inclinación de pelvis en anteversión, ángulo máximo de inclinación de pelvis en retroversión y ángulo máximo de flexión lumbar se asocian con molestias o dolor lumbar. Sin embargo, es posible establecer que la asociación entre la práctica de ciclismo y el dolor lumbar no ha sido suficientemente estudiada, lo que nos hace inferir que surge la necesidad de actualizar la información con el objetivo de prevenir este tipo de lesiones asociadas a la posición en ciclismo. Abstract. This article analyzed the relationship between the flexion position maintained during cycling and the possible relationship with low back pain. A systematic review was carried out through the PRISMA process between 2015-2020, in the PubMed, PEDro, Scopus and Web of Science databases, using the terms; "cycling", "cyclist", "position", "positioning", "injury from overuse", "biomechanics of the spine", "lumbar region", "low back pain". Five articles were selected that met all the inclusion criteria. Selected articles showed changes in pelvic tilt, torso flexion angles in medium and low strokes of the handlebars of the road bike and mountain bike, variations of the highest seat or the appropriate backrest according to the groin length, knee position 40 and trunk 35º simultaneously when the pedal is at 180º, while in anatomical position they have been described; The maximum angle of pelvic tilt in anteversion, the maximum angle of pelvic tilt in retroversion and the maximum angle of lumbar flexion are associated with pain or discomfort in the lumbar region. However, it is possible to establish that the association between cycling and low back pain has not been sufficiently studied, which leads us to infer that there is a need to update the information in order to prevent this type of injury associated with the position in cycling.

El propósito del estudio fue determinar el grado de validez y fiabilidad del cuestionario Escala de Percepción de Competencia Docente en Educación Física en la Atención de las Personas en Situación de Discapacidad (ECoDEFyD). La muestra fue de tipo intencionada, compuesta por 37 profesores que imparten clases de Educación Física a nivel de educación básica y media. El instrumento original se modificó en base al juicio de expertos, y estos aprobaron su uso final alcanzando una validez de contenido aceptable. El instrumento modificado alcanzó una consistencia interna elevada (ɑ > 0.92) y una fiabilidad relativa excelente (coeficiente de correlación intraclase = 0.962), demostrando que el instrumento ECoDEFyD es un instrumento válido y fiable para medir la percepción de competencia y necesidades más urgentes frente a la inclusión de estudiantes con necesidades educativas especiales permanentes, de los profesores de Educación Física, resultando ser adecuado para tomar decisiones a partir de sus resultados. Abstract. The purpose of this study was to determine the degree of validity and reliability of the questionnaire Scale of Perception of Teaching Competence in Physical Education in the Attention of People with Disabilities (ECoDEFyD). The sample was of intentional type, in 37 teachers who teach Physical Education classes at the basic and high school level. The original instrument was modified based on the judgment of experts, and they approved its final use, reaching an acceptable content validity. The modified instrument achieved high internal consistency (ɑ > 0.92) and excellent relative reliability (intra-class correlation coefficient = 0.962), demonstrating that the ECoDEFyD instrument is a valid and reliable instrument to measure the perception of competence and the most urgent needs in the face of the inclusion of students with permanent special educational needs, of Physical Education teachers, proving to be adequate to make decisions based on their results.

Introduction: Due to the current COVID-19 pandemic, many countries have implemented control and prevention measures, such as compulsory lockdowns, affecting all spheres of life. Since the field of professional soccer is no exception, such measures may have a negative impact on the player’s well-being and their perceived training loads. Objective: To determine the impact of COVID-19 lockdown measures on the training load and the well-being of female professional soccer players in Chile. Materials and methods: Exploratory, cross-sectional, descriptive study conducted on 32 players of the Chile women’s national soccer team. The perception of training load and the level of well-being were assessed by means of the rating of perceived exertion (RPE) scale and a questionnaire developed in 2010, respectively. Both the administration of the questionnaire and the permanent monitoring of the RPE records were carried out in two periods of 12 weeks: regular preparatory phase (12/12/2019-10/03/2020) and lockdown (16/03/2020-07/06/2020). Data were analyzed using descriptive statistics and the Wilcoxon test was used to determine if there were significant differences between periods. Results: Significant differences (p

El propósito de este estudio fue determinar los indicadores cinemáticos relevantes entre categorías Elite y Sub-23 de ciclistas de cross country mountain bike (MTB) en la técnica de ascenso. La muestra fue compuesta por ciclistas Sub-23 (n=5; 18.8±0.5 años) y Elite (n=7; 24.2±2.0 años), todos los participante varones, diestros y ciclistas federados de competiciones de cross country MTB. Los datos fueron registrados desde el plano sagital al ascender por un terreno con una pendiente de 9.5±0.5% con la técnica de videofotogrametría. Los indicadores que presentaron diferencias entre categorías fueron: velocidad angular ciclo pedaleo izquierdo (p=0.04; g=-1.22), tiempo ciclo pedaleo izquierdo (p=0.02; g=1.44), velocidad angular ciclo pedaleo izquierdo de la fase preparatoria (p=0.03; g=-1.37), mientras que para la velocidad articular; velocidad de la cadera izquierda en fase de envión (p=0.029; g=-1.38), velocidad del tobillo izquierdo (p=0.005; g=-1.94) y tobillo derecho (p=0.002; g=-2.17) en fase de recuperación. Abstract. The purpose of this study was to determine the relevant kinematic indicators between Elite and Under-23 categories of cross country mountain bike (MTB) cyclists in the climbing technique. The sample was made up of Under-23 (n=5; 18.8±0.5 years) and Elite (n=7; 24.2±2.0 years) cyclists, all male and right-handed, federated participants of cross-country MTB competitions. The data were recorded from the sagittal plane to the ascending one through a terrain with a slope of 9.5±0.5% with videophotogrammetry. The indicators that showed differences between categories were: left pedaling cycle angular velocity (p=0.04; g=-1.22), left pedaling cycle time (p=0.02; g=1.44), left pedaling cycle angular velocity of the preparatory phase (p=0.03; g=-1.37), while for joint speed; speed of the left hip in clean and jerk phase (p=0.029; g =-1.38), speed of the left ankle (p=0.005; g=-1.94) and right ankle (p=0.002; g=-2.17) in recovery phase.

El propósito de esta investigación fue construir un instrumento de evaluación del desempeño técnico-táctico de los jugadores de vóleibol, que posibilite la toma de decisión por parte del entrenador. Las variables de estudio fueron la evaluación del desempeño técnico de los jugadores de vóleibol y la evaluación del desempeño táctico de un equipo de vóleibol, a través del programa Microsoft Office Excel®, que permitió registrar y acceder en tiempo real a la información durante el desarrollo de un partido. La evaluación de desempeño técnico abarcó fundamentos técnicos, con su respectiva categorización de valores. La evaluación de desempeño táctico del equipo se compuso por la organización de la levantada, el porcentaje de eficiencia técnica del ataque en k1 y k2, y el análisis de distribución de levantada y eficiencia de ataque por rotación. El programa consiste en 6 libros de Excel® que trabajan de manera interrelacionada. Los primeros cinco corresponden a los sets jugados y el sexto, al resumen de toda la información ingresada. Las hojas se dividen en: Activas (Hoja final, hoja general, hoja diferencia, hoja atqefi, hoja análisis atqk2 y hoja resumen por jugador), Intermedias (Datos y ATAQRSM), y Pasivas (Tablas). El instrumento de evaluación desempeño técnico-táctico aporta y desarrolla en el ámbito de la evaluación objetiva de los rendimientos técnicos-tácticos. Este instrumento presenta características de bajo costo y fácil operación constituyen fortalezas que beneficiarán a todos aquellos entrenadores que lo utilicen. Abstract. The purpose of this study was to build an instrument for evaluating the technical-tactical performance of the volleyball players, which enables a decision making by the coach. The study variables were the evaluation of the technical performance of the volleyball players and the evaluation of the tactical performance of a volleyball team. A computer tool for evaluating the technical-tactical performance of volleyball players was developed. Through a computer program established in Microsoft Office Excel, which allowed registering and immediately accessing the necessary information during the development of a game. The variable of technical performance evaluation covers the following technical foundations, with their respective categorization of values. The tactical performance evaluation variable of the team was composed by the distribution of the raised, the technical efficiency percentage of the attack in k1 and k2, and the analysis of raised distribution and efficiency of attack by rotation. The program consists of 6 Excel books that work in an interrelated manner. The first five correspond to the sets played and the sixth corresponds to the summary of all the information entered. The match data were entered in the story sheet, to codify the technical-tactical situations of the game full. The sheets are divided into: Active (Final sheet, general sheet, difference sheet, atqefi sheet, atqk2 analysis sheet and summary sheet per player), Intermediate (Data and ATAQRSM), and Passive (Tables). The instrument of statistical evaluation of the technical-tactical performance of volleyball players serves as a contribution to the entire national volleyball environment, for its development in the field of objective evaluation of technical performances. This instrument its low cost and easy operation are strengths that will benefit all those coaches that use it.

The present study aimed to verify the quarantine’s effects during a serious viral outbreak on the cardiovascular and performance associated with the Yo-Yo test in a sample of professional soccer players. 20 high-level soccer players (n = 20; age: 26 ± 4 years-old; weight: 76.85 ± 6.7 kg; height: 179 ± 6 cm) participated in this study. The intermittent Yo-Yo test was performed pre- and post- COVID-19 quarantine in a random order. During each test, the soccer players’ running performance outcomes were monitored using a portable 5-Hz GPS with a 100 Hz accelerometer and a paired t-test was conducted at a p-value of ≤ 0.05. The main results demonstrated significant differences between pre- versus post-COVID-19 quarantine in the following variables: relative distance (161.7 ± 5.9 > 141.1 ± 33.8 m/min), maximal speed (18.7 ± 0.9 > 18.2 ± 0.6 km/h), acceleration (60 ± 20 frequency > 52 ± 16 frequency), deceleration (34 ± 13 frequency > 27 ± 6 frequency), sprints > 19 km/h [0.8 (0.2;3)% >0.5 (0;0.5)%], and in high intensity running distance [16.48 (2.68;41.64)m > 0.827 (0.164;3.0)m]. We concluded that COVID-19-related restrictions and quarantine COVID-19 demonstrated adverse effects on professional soccer players’ Yo-Yo tests performance.

In such a competitive combat sport as judo, it is important that the training is carefully planned so that the athlete can stand out in the international competition. In this context, it is important that the trainer and evaluator are accurate regarding the measures taken of the athlete. Such measures, when correctly performed, can prepare the trainer with tools that allow prescribing contextualized training. The present point of view will show how kinanthropometric variables can be considered by coaches and evaluators when performing technical-tactical and biomechanical analysis in judo athletes. There are differences between sex and weight divisions as to the actions that are prevalent in each one of the categories. Lighter divisions performances must have specific training regarding approach and gripping. Attention should be paid to anticipation in athletes of the light and middle divisions. The rating of force development is the most important biomechanical measure.

Background Pain assessment is a key measure that accompanies treatments in a wide range of clinical settings. A low-cost valid and reliable pressure algometer would allow objective assessment of pressure pain to assist a variety of health professionals. However, the pressure algometer is often expensive, which limits its daily use in both clinical and research settings. Objectives This study aimed to assess the instrumental validity, and the intra- and inter-rater reliability of an inexpensive digital adapted pressure algometer. Methods A single rater applied 60 random compressions on a force platform. The pressure pain thresholds of 20 volunteers were collected twice (3 days apart) by two raters. The main outcome measurements were as follows: the maximal peak force (in kPa) and the pressure pain threshold (adapted pressure algometer vs. force platform). Cronbach’s α test was used to assess internal consistency. The standard error of measurement provided estimates of measurement error, and the measurement bias was estimated with the Bland–Altman method, with lower and upper limits of agreement. Results No differences were observed when comparing the compression results (P = 0.51). The validity and internal intra-rater consistencies ranged from 0.84 to 0.99, and the standard error of measurement from 0.005 to 0.04 kPa. Very strong (r = 0.73–0.74) to near-perfect (r = 0.99) correlations were found, with a low risk of bias for all measurements. The results demonstrated the validity and intra-rater reliability of the digitally adapted pressure algometer. Inter-rater reliability results were moderate (r = 0.55–0.60; Cronbach’s α = 0.71–0.75). Conclusion The adapted pressure algometer provide valid and reliable measurements of pressure pain threshold. The results support more widespread use of the pressure pain threshold method among clinicians.

Conocer la percepción institucional de los agentes que componen una comunidad resulta relevante para mejorar los servicios educativos que se prestan, además permiten instaurar mecanismos de seguimiento, control e innovación dentro de las universidades para lograr una mejora continua. El objetivo de la presente investigación fue determinar la percepción institucional de los estudiantes de Pedagogía en Educación Física de Chile. Se aplicó la escala de percepción hacia la carrera educación física a 908 estudiantes, de los cuales 317 eran mujeres (34.9%) y 591 hombres (65.1%). El promedio de edad fue de 20.1±2.4 y 359 eran de primer año, 316 de segundo y 233 de tercer año de diferentes instituciones de educación superior de Chile. Se encontraron diferencias significativas al comparar las universidades privadas con las públicas (percepción favorable hacia las instituciones privadas) en la gestión universitaria (p=.000) y protestas estudiantiles (p=.000); por otro lado, también se puede enfatizar que los estudiantes perciben que les hace falta conocer técnicas de estudio, sobre todo los alumnos provenientes de colegios municipales (p=.049) en relación con los establecimientos particulares. Se concluye que la percepción institucional de los estudiantes de pedagogía en educación física que tiene mayor relevancia es la gestión académica. Son necesarias futuras investigaciones con otras variables y de corte longitudinal. Abstract. Knowing the institutional perception of the agents building up a community is important to improve educational services provided, and allows for the establishment of monitoring, control, and innovation mechanisms within universities to achieve continuous improvement. The objective of this research was to determine the institutional perception of students of Pedagogy in Physical Education from Chile. A total of908 students (317 women [34.9%]; and 591 men [65.1%]) with average age of 20.1±2.4 years old, enrolled in first-year (359), second year (316), and third year (233) at different higher education institutions in Chile filled the Perception of Physical Education Degree Scale.Results: Significant differences were found comparing private and public universities (private institutions showing more favorable perceptions) in university management (p=.000) and students' protests (p=.000); on the other hand, it can also be emphasized that students perceive that they need to know study techniques, especially students from municipal schools (p=.049) in relation to private institutions.As a conclusion, the most relevant institutional perception of students of pedagogy in physical education regards academic management. Future research with other variables and longitudinal character is necessary.

This brief research report showed technical-tactical behaviors of male and female judo cadets during combats, comparing the frequency and time of judo combat actions, techniques and penalties. The data was composed for 3,240 sequential technical-tactical behavior analysis from 108 female and 300 male cadet combats recorded of public judo championships. Combat, standing combat moments, approach action, gripping action, attack, groundwork actions and pause moment were observed and determinant technical-tactical behaviors (frequencies of actions, penalties and type of attacks) analysis were done with FRAMI software, followed by Mann-Whitney and Student’s t-test, p ≤ 0.05. Our main results indicated that male cadets with 58.66s ± 50.26s demonstrated longer gripping action than female with 38.44s ± 30.44s, as standing combat (tachi-waza) had differences between male with 96.8s ± 72s and female athletes with 75.85s ± 56.97s. Moreover, male cadets had higher sacrifice techniques (sutemi-waza) actions than female athletes. This information could be used to a best performance associated with “psyching-up” as much as it could be used on physical training and technical-tactical ability of female and male cadets.