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Objectives To determine the inter-rater and intra-rater reliability of frontal and sagittal plane landing kinematic measures during drop jump (DVJ) and tuck jump (TJA) tasks in male youth soccer players, to assess the concurrent validity between DVJ and TJA tests, and to evaluate the ability of both tasks to detect differences between players’ stage of maturation. Design Cross-sectional study. Participants 223 male youth soccer players. Main outcome measures Frontal plane knee projection angles (FPPA), and hip (HF), knee (KF) and ankle (AF) flexion angles at initial contact (IC) and peak flexion (PF) (i.e., the deepest landing position) in the sagittal plane were assessed. Results Good-to-excellent inter- and intra-rater reliability (ICC > 0.75; TEMST 10; error 0.6) were only identified for the TJA. Pre-PHV group reported higher FPPA, HF-IC, HF-PF, and KF-IC values, as well as lower AF-IC than post-PHV. Pre-PHV also displayed greater HF-IC and KF-IC than circa-PHV group. Conclusions Although both tests are reliable, the TJA might be viewed as a more informative tool given it shows greater FPPA and can also detect differences by maturity status.

The main purpose of this study was to conduct a systematic review and meta-analysis quantifying the incidence of injuries in futsal players. A systematic search was conducted using MEDLINE, PubMed, Web of Science and Scopus databases and subsequently six studies (14 cohorts) were selected. Two reviewers independently extracted data and assessed trial quality and risk of bias using the Strengthening the Reporting of Observational Studies in Epidemiology statement and Newcastle Ottawa Scale, respectively. Quality of evidence was also determined using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Separate meta-analyses for male and female players were conducted using a Poisson random-effect regression model approach. The overall and match incidence rates in elite male futsal players were 6.8 (95% CI = 0.0 – 15.2) and 44.9 (95% CI = 17.2 – 72.6) injuries/1000 hours of exposure. Pooled training injury rate in male players was not calculated due to the lack of studies reporting training injuries in this cohort. For females, an overall, training and match incidence rates of 5.3 (95% CI = 3.5 - 7), 5.1 (95% CI = 2.7 - 7.6) and 10.3 (95% CI = 0.6 - 20.1) injuries/1000 hours of exposure were reported. In males, match incidence rate in International tournaments was 8.5 times higher than in national leagues (77.2 [95% CI = 60.0 - 94.5] vs 9.1 [95% CI = 0.0 – 19.3] for international tournaments and national leagues, respectively). Elite male and female futsal players are exposed to a substantial risk of sustaining injuries, especially during matches.

To explore the incidence, burden, and pattern of injuries in Spanish male youth soccer players during a 9-month competitive season (from September to May-June).Prospective cohort study.314 young (10-19 years) soccer players.Incidence, burden, location, type, severity, mechanism, and circumstance of injuries, as well as potential differences by tactical position, month of the year, age group, and maturity status.A total of 146 time-loss injuries were sustained by 101 different players. This resulted in an overall injury incidence of 3.1 injuries per 1000 h, a training injury incidence of 1.8 injuries per 1000 h, and a match injury incidence of 11.2 injuries per 1000 h. The probability of injury over the season was 34%. Most of the injuries affected the lower extremity and were classified as muscle/tendon injuries, with hamstring muscle injuries representing the most burdensome diagnosis. The incidence of injuries increased with age and maturation, but a heightened risk of overuse injuries during periods around peak height velocity was also identified.These findings suggest a need for implementing specific injury prevention measures. Due to the high burden shown, these measures should mainly focus on reducing the number and severity of hamstring muscle injuries.

Background and method: This meta-analysis sought to: quantify the effects of isometric resistance training (IRT) on the magnitude of change in systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) and resting heart rate in adults; and examine whether the magnitude of change in SBP, DBP, MAP and heart rate was different with respect to the patient demographic characteristics and IRT parameters. To be included in the meta-analysis, studies had to be randomized controlled trials lasting 2 or more weeks, investigating the effects of IRT on blood pressure in adults. The methodological quality of the studies selected was evaluated using the PEDro scale. For each main outcome measure, an average effect size and its respective 95% confidence intervals were calculated.\ud \ud Results: A total of 16 articles (492 participants) fulfilled the selection criteria (mean quality score in the PEDro scale of 5.9). Compared with control groups, IRT groups showed statistically significant (P < 0.05) and clinically relevant (>2 mmHg) positive effects on the SBP (-5.23 mmHg) and MAP (-2.9 mmHg). IRT groups also showed statistically significant, but not clinically relevant reduction in DBP (-1.64 mmHg). Furthermore, IRT groups did not report any statistically significant and clinically relevant (>5 bpm) effect on resting heart rate (-0.08 bpm).\ud \ud Conclusion: The analysis of moderator variables showed that none of them exhibited a statistically significant relationship with the positive effects of IRT for lowering blood pressure. Therefore, IRT may be considered an appropriate nonpharmacologic treatment for lowering SBP and MAP.

Hamstring strain injury (HSI) is one of the most prevalent and severe injury in professional soccer. The purpose was to analyze and compare the predictive ability of a range of machine learning techniques to select the best performing injury risk factor model to identify professional soccer players at high risk of HSIs. A total of 96 male professional soccer players underwent a pre-season screening evaluation that included a large number of individual, psychological and neuromuscular measurements. Injury surveillance was prospectively employed to capture all the HSI occurring in the 2013/2014 season. There were 18 HSIs. Injury distribution was 55.6% dominant leg and 44.4% non-dominant leg. The model generated by the SmooteBoostM1 technique with a cost-sensitive ADTree as the base classifier reported the best evaluation criteria (area under the receiver operating characteristic curve score=0.837, true positive rate=77.8%, true negative rate=83.8%) and hence was considered the best for predicting HSI. The prediction model showed moderate to high accuracy for identifying professional soccer players at risk of HSI during pre-season screenings. Therefore, the model developed might help coaches, physical trainers and medical practitioners in the decision-making process for injury prevention.

The purposes of this study were to describe the lower extremities joints range of motion (ROM) profile using a comprehensive approach in futsal players and to examine potential player position (goalkeepers vs. outfield players), competitive level (first [top] division vs. second division), number of playing years, sex (males vs. females), and bilateral (dominant limb vs. non-dominant limb) differences. A total of 72 male and 67 female elite futsal players from 11 clubs were measured of passive hip (flexion with knee flexed [HFKF] and extended [HFKE], extension [HE], abduction [HA], external [HER], and internal [HIR] rotation), knee (flexion [KF]) and ankle (dorsiflexion with knee flexed [ADFKF] and extended [ADFKE]) ROMs. Bayesian inferences exploring differences between player position, competitive level, sex and limb were made. A Bayesian correlation analysis was conducted to explore the influence of playing years on joints ROMs. The results showed no significant player position or competitive level related differences in any average ROM score. However, statistically significant sex-related differences were documented whereby female players reported higher hip and knee joints ROM average values than their male counterparts. Especially relevant were the proportions of males (72%) and players from teams engaged in the second division (61%) displaying limited HFKE ROMs. Likewise, around 35% of all players showed restricted ADFKF ROMs. In addition, approximately 21, 18, 22, and 25% of the futsal players were identified as having bilateral asymmetries (≥8°) for HA, HIR, HER, and KF ROMs, respectively. Finally, Bayesian correlation analysis did not report any significant association between years of playing futsal and ROM measures (all r values < 0.34). The implications that these restricted HFKE and ADFKF ROMs and bilateral asymmetries in hip (abduction, internal and external rotation) and knee (flexion) ROMs caused by the practice of futsal may have on physical performance and injury risk warrant future research.

The aim of the present study was to analyse the effects of playing two badminton matches on the same day on the shoulder profile (i.e., range of motion (ROM) and strength) of young badminton players.Cross-sectional study.Indoor sports facility.Thirty-one elite junior badminton players (age 16.6 ± 1.0 years, body mass 63.9 ± 6.1 kg, height 174.8 ± 6.1 cm), including 19 boys and 12 girls.Shoulder passive internal rotation (IR) and external rotation (ER) ROM as well as shoulder IR/ER maximal isometric strength were measured before and after a competition including two competitive matches.Significant decreases (p 0.05) were found in the shoulder ROM (i.e., dominant and non-dominant ER ROMs as well as in the dominant and non-dominant total arc of motion [TAM]) in boys, while in girls, significant increases (p 0.05) were found in the non-dominant ER absolute strength, with significant decreases were found in the non-dominant ER ROM and the non-dominant TAM.Playing two badminton matches on the same day led to gender-specific changes on the shoulder profile (i.e., ROM and strength) of young elite badminton players, with more impact on the shoulder profile of boys compared to girls.

Background Although the Star Excursion Balance test (SEBT) has shown a good intrasession reliability, the intersession reliability of this test has not been deeply studied. Furthermore, there is an evident high influence of the lower limbs in the performance of the SEBT, so even if it has been used to measure core stability, it is possibly not the most suitable measurement. Objective (1) To assess the absolute and relative between-session reliability of the SEBT and 2 novel variations of this test to assess trunk postural control while sitting, ie, the Star Excursion Sitting Test (SEST) and the Star Excursion Timing Test (SETT); and (2) to analyze the relationships between these 3 test scores. Design Correlational and reliability test–retest study. Setting Controlled laboratory environment. Participants Twenty-seven physically active men (age: 24.54 ± 3.05 years). Method Relative and absolute reliability of the SEBT, SEST, and SETT were calculated through the intraclass correlation coefficient (ICC) and standard error of measurement (SEM), respectively. A Pearson correlation analysis was carried out between the variables of the 3 tests. Main Outcome Measures Maximum normalized reach distances were assessed for different SEBT and SEST directions. In addition, composite indexes were calculated for SEBT, SEST, and SETT. Results The SEBT (dominant leg: ICC = 0.87 [0.73-0.94], SEM = 2.12 [1.66-2.93]; nondominant leg: ICC = 0.74 [0.50-0.87], SEM = 3.23 [2.54-4.45]), SEST (ICC = 0.85 [0.68-0.92], SEM = 1.27 [1.03-1.80]), and SETT (ICC = 0.61 [0.30-0.80], SEM = 2.31 [1.82-3.17]) composite indexes showed moderate-to-high 1-month reliability. A learning effect was detected for some SEBT and SEST directions and for SEST and SETT composite indexes. No significant correlations were found between SEBT and its 2 variations (r ≤ .366; P > .05). A significant correlation was found between the SEST and SETT composite indexes (r = .520; P > .01). Conclusions SEBT, SEST, and SETT are reliable field protocols to measure postural control. However, whereas the SEBT assesses postural control in single-leg stance, SEST and SETT provide trunk postural control measures with lower influence of the lower-limbs. Level of Evidence III

Resumen. El BodyJump® es una disciplina que ha irrumpido fuertemente en los últimos años en los centros deportivos. Pese a ello, no hay evidencias que permitan respaldar su uso como programa eficaz y seguro para la mejora de la condición física y salud. Por lo tanto, el objetivo principal de este estudio fue analizar el efecto de un programa de corta duración de BodyJump® sobre la condición física y salud. Un total de tres mujeres adultas sedentarias (edad: 23 años; 55,3 ± 2,8 kg; 161,3 ± 7,1 cm) completaron este estudio de casos siendo sometidas a un programa de BodyJump® durante cuatro semanas. Un total de 17 medidas de condición física y salud y dos medidas relacionadas con sintomatología del tendón de Aquiles y rotuliano fueron definidas como variables dependientes. El efecto del programa de BodyJump® sobre las variables dependientes fue determinado a través del estadístico tamaño del efecto. Un tamaño del efecto pequeño (d = 0,5-1,25) fue encontrado en las medidas relacionadas con la fuerza y resistencia de la musculatura del tronco, potencia de salto vertical con contra-movimiento y equilibrio dinámico. Para el resto de medidas de condición física y salud se observó un cambio trivial o no relevante tras la intervención (d < 0,5). Los hallazgos del presente estudios informan de que un programa de BodyJump®podría ser considerado una actividad eficiente para la mejora de la fuerza y resistencia muscular del tronco, potencia y equilibrio dinámico en mujeres adultas jóvenes sedentarias. Abstract. BodyJump® is a discipline that has broken out strongly in recent years in fitness centers. However, there is no evidence to support its use as an effective and safe program for improving fitness and health. Therefore, the main objective of this study was to analyze the effect of a short-term BodyJump® program on fitness and health. A total of three sedentary adult women (age: 23 years, 55.3 ± 2.8 kg, 161.3 ± 7.1 cm) completed this case study undergoing a BodyJump® program for four weeks. A total of 17 measures of fitness and health and two measures related to symptoms of Achilles and patellar tendon were defined as dependent variables. The effect of the BodyJump® program on the dependent variables was determined through the statistical effect size. A small effect size (d = 0.5-1.25) was found in measures related to trunk musculature strength and endurance, power of countermovement vertical jump and dynamic balance. For the rest of physical and health measures, a trivial or non-relevant change was observed after the intervention (d

BACKGROUND: Limited ranges of motion (ROM) has been considered as a primary risk factor for some football injuries, but only a few studies have analysed differences in lower extremity joints. The main purposes were (a) to describe the lower extremity ROM profile in professional football players; and (b) to examine differences between goalkeepers and outfield players.\ud METHODS: 82 professional male football players from 4 teams were measured in the 2013 pre-season. Measures of passive hip (flexion with knee flexed [PHFKF] and extended [PHFKE], extension [PHE], abduction [PHA], external [PHER] and internal [PHIR] rotation), knee (flexion [PKF]) and ankle (dorsiflexion with knee flexed [ADFKF] and extended [ADFKE]) ROMs were taken. Magnitude-based inferences exploring differences between player position and limb were made.\ud RESULTS: 46% of all participants showed restricted PHFKE and/or around 30% showed restricted ADFKF ROM values. Contrarily, most players reported normal PHFKF, PHE, PHIR and PHER as well as PKF ROM scores with percentage values close to 100%. Bilateral meaningful differences for PHA, PHIR and PHER were found in approximately 30% of outfield players and goalkeepers. Statistical analysis found trivial differences between players for PHFKE, PHE, PHIR, PHER, ADFKE and ADFKF. However, moderate differences between players were found for PHFKF, PHA and PKF, with goalkeepers demonstrating higher values than outfield players. \ud CONCLUSIONS: The findings of this study reinforce the necessity of prescribing exercises aimed at improving PHFKE and ADFKF ROM within everyday football training routines. In addition, as some bilateral deficits were observed, unilateral training should be considered where appropriate.

Objective The aims of this study were to analyze the shoulder functional profile of young male and female tennis players and to establish the relationship among physical variables and serve speed. Methods A total of 128 Spanish tennis players (Under-13 (n = 32/32 males/females) and Under-15 (n = 36/28 males/females), were tested during National training camps. Tests included passive shoulder range of motion (ROM) for both internal (IR) and external rotation (ER) and isometric strength (i.e., IR and ER) of the dominant/non-dominant shoulders, medicine ball throws (MBT), and serve speed. Age and sex pairwise comparisons were carried using the Hedges’ g index (dg). Results Results showed age and sex effects on serve speed and all MBT, with males showing greater changes (1.51≤dg≤1.98) with age than females (0.92≤dg≤1.35; p

PurposeThe purpose of this study was to analyse the relationship between several parameters of neuromuscular performance with dynamic postural control using a Bayesian Network Classifiers (BN) based analysis.MethodsThe y-balance test (measure of dynamic postural control), isokinetic (concentric and eccentric) knee flexion and extension strength, isometric hip abduction and adduction strength, lower extremity joint range of motion (ROM) and core stability were assessed in 44 elite male futsal players. A feature selection process was carried out before building a BN (using the Tabu search algorithm) for each leg. The BN models built were used to make belief updating processes to study the individual and concurrent contributions of the selected parameters of neuromuscular performance on dynamic postural control.ResultsThe BNs generated using the selected features by the algorithms correlation attribute evaluator and chi squared reported the highest evaluation criteria (area under the receiver operating characteristic curve [AUC]) for the dominant (AUC = 0.899) and non-dominant (AUC = 0.879) legs, respectively.ConclusionsThe BNs demonstrated that performance achieved in the y-balance test appears to be widely influenced by hip and knee flexion and ankle dorsiflexion ROM measures in the sagittal plane, as well as by measures of static but mainly dynamic core stability in the frontal plane. Therefore, training interventions aimed at improving or maintaining dynamic postural control in elite male futsal players should include, among other things, exercises that produce ROM scores equal or higher than 127° of hip flexion, 132.5° of knee flexion as well as 34° and 30.5° of ankle dorsiflexion with the knee flexed and extended, respectively. Likewise, these training interventions should also include exercises to maintain or improve both the static and dynamic (medial-lateral plane) core stability so that futsal players can achieve medial radial error values lower than 6.69 and 8.79 mm, respectively.