Background: Calf muscle fatigue has been shown to affect movement patterns and may contribute to increased injury risk, particularly in the knee joint. Objective: This study aims to investigate the effect of calf muscle fatigue on lower limb kinematics during cutting maneuvers in female athletes with and without dynamic knee valgus (DKV). Methods: This case-control study included female athletes with (n = 12) and without dynamic knee valgus (n = 12). The cutting maneuver kinematics were measured with 10 cameras motion analysis before and after calf muscle fatigue, which was induced using an isokinetic dynamometer through repeated maximal plantarflexion contractions at the time point corresponding with peak knee valgus angle. A two-way mixed-design analysis of variance was conducted to analyze within-group differences between the pre-test and post-test results. Results: The findings indicated that calf muscle fatigue was associated with a significant decrease in knee flexion (p = .006) and increases in valgus angle (p = .003) and external rotation angle (p = .028), during the cutting maneuver. Also, calf muscle fatigue significantly increased ankle inversion (p = .028) and decreased hip flexion (p = .030) in the DKV group. Moreover, a significant difference was observed in the effect of fatigue between the two groups, such that the ankle inversion (p = .021) and hip flexion angle (p = .006) changed more in the DKV group than in the group without DKV. Conclusions: This study showed significant effects of calf muscle fatigue on the lower limb kinematics of female athletes. These alterations in movement patterns, especially in athletes with DKV, may contribute to a higher risk of injury, particularly anterior cruciate ligament injuries, due to compromised joint stability and altered biomechanics.

Background: Over the past few decades, CrossFit has become a very popular physical activity. However, there is little literature on its effect, as resistance training, on the performance of soccer players.Objective: This study examined the effects of 12 weeks of CrossFit training on muscular strength, speed, agility, and VO2max in young male soccer players. Methods: Thirty-eight soccer players were divided randomly into the experimental group (n = 19, age 17.32 ± 1.02 years, body height 1.76 ± 0.15 m, body mass 63.24 ± 5.68 kg, body mass index 21.34 ± 1.32 kg/m2) and control group (n = 19, age 17.21 ± 1.70 years, body height 1.74 ± 0.16 m, body mass 63.43 ± 5.21 kg, body mass index 21.45 ± 1.21 kg/m2). Both groups underwent 12 weeks of the usual soccer training program, including physical exercises on a regular basis, three times a week. Additionally, in the experimental group, a training program based on high-intensity functional physical activity was added during each training session as part of the usual weekly training regimen. Pre- and post-intervention tests were performed to measure player performance, including 30-m sprint, Yo-Yo intermittent recovery test level 1, vertical jump, agility T-test, sit-ups, and push-ups during 60 s. Results: A significant group x time effect was found for all tests: 30-m sprint (p = .012, ηp2 = .42), Yo-Yo test (p = .029, ηp2 = .23), vertical jump (p = .002, ηp2 = .46), T-test (p = .002, ηp2 = .21), sit-ups (p < .001, ηp2 = .55), push-ups (p = .001, ηp2 = .25). The improvement was higher in the experimental group for all variables. Conclusions: CrossFit training is an effective strategy for improving the physical capacities in young soccer players.

Background: Many young people spend a significant amount of time playing esports and video games during the day and meet their social and psychological needs on these platforms. This situation can lead to people developing an addiction to esports games over time. This situation brings about many problems, notably the gradual isolation of individuals from social life over time. Especially during university years, many individuals turn to esports games as a way to escape from various issues. There could be numerous reasons for this inclination. Objective: This study aimed to uncover the factors contributing to university students' addiction to esports games. Methods: The study utilized the Q Method, incorporating qualitative and quantitative research features. Twenty-six university students who play games for at least 21-24 hours a week were included in the study group. The study group was determined using the snowball sampling method. The principal component analysis method was used to analyze the data. Results: The factors that contribute towards university students' addiction to esports games are wanting to socialize and make new friends, wanting to be a professional-level esports player and earning money by sharing game videos on social media. Conclusions: The study's findings suggest that various factors, including psychological, economic, social, and professional aspirations, contribute to esports addiction. It was also shown that there are individual benefits that contribute to the formation of addiction to these games, as well as the potential harm that esports games can cause to individuals.

Background: Football task design lies in manipulating the relevant features of the game considering the consequences these modifications can have on players' performance. Adding an extra ball may boost academy footballers' possibilities of interaction and challenge them to readjust their motor conduct according to the uncertainty of a novel game scenario. Objective: This study compared young footballers' spatial exploration index (SEI) overall and one by one during simulated matches played with one or two balls. Methods: Forty-four association football players from U14 and U16 teams of the same club played two 60-minute matches with all the official game rules and regulatory conditions. The unique difference was that one match was played with a single ball and the other with two balls simultaneously. Positional data were gathered during matches using a Global Positioning System (GPS) to assess each footballer's SEI central tendency and approximate entropy (ApEn) measures. Results: The average SEI of both U14 (p = .01; η2 = .066, medium) and U16 (p < .001; η2 = .187, large) players was lower, and its ApEn higher (U14: p < .001, η2 = .014, small; U16: p < .001, η2 = .035, small), during the two-ball match in comparison to the standard one-ball match. The graphical representation shows how their relative positioning changed between matches, breaking team formation in two during the two-ball condition. From an individual perspective, the second ball affected defenders mainly. Most of them reduced their intervention area, acted more unpredictably within this, and got closer to their target compared with the standard one-ball match. Conclusions: Adding an extra ball led young footballers to explore less space more unpredictably, especially defenders. So, a one-by-one analysis may assist coaches in evaluating each player's tactical response to football training.

The detection of sports talent has been a recurring concern in sports science. It has been found that there is great variability in determining which athletes may perform better in sports. Objective: The objective of the present research was to analyse the influence of anthropometric variables, physical condition, chronological and biological age, and training variables on the possibility of being selected for the regional team competing in the national championship in adolescent volleyball players. Methods: A total of 100 volleyball players (48 boys, age 14.17 ± 1.00 years; 52 girls, age 14.22 ± 1.14 years) participated in the present crosssectional design study and completed a sociodemographic and sports questionnaire. Participants underwent an anthropometric assessment, including basic measurements, skinfolds (triceps, subscapular, biceps, iliac crest, supraspinal, abdominal, thigh and calf), girths (arm relaxed, flexed and tensed arm, waist, hips, middle thigh and calf), breadths (biacromial, biiliocristal, humerus, femur, and bi-styloid), lengths (acromiale-radiale, radiale-stylion and stylion-medio-dactylion); and a height (iliospinale). After that, ∑6 and ∑8 skinfolds, body composition, upper limb length and corrected girths were calculated. Physical fitness was assessed by sit-and-reach, back scratch, long jump, medicine ball throw, countermovement jump, sprint and agility test. The maturity offset was estimated. Statistical analysis included χ 2 , to analyse differences between those selected and not selected, and odd ratio (OR), to assess the possibility of being selected for competing in the national championship as a function of anthropometric, physical fitness and training variables. Results: It was observed that, in the group of boys, higher values in the variables related to bone mass increased the possibility of being selected (OR = 2.17-3.08). Better performance in the physical tests related to power production was a predictor of higher chances of being selected in both groups of boys and girls (OR = 0.48-2.53). In the case of the boys, a more advanced maturation process increased the possibility of being selected (OR = 0.61-1.69). Better perception of the coach in both groups and higher training volume in the case of the boys increased the chances of being selected (OR = 1.75-3.70). Conclusions: Better performance in the physical condition tests is an indicator of a greater probability of being selected in both boys and girls, while the anthropometric variables, a higher biological age, the volume of training and perception of the coach were the only determinants in the group of boys.

Background: Selective attention and visuospatial orienting attention are important cognitive functions for children's development. Testing based on touch-based mobile technology platforms is becoming increasingly widespread in psychological assessment. Objective: The aim of the study was to investigate the reliability and validity of the newly developed touchscreen tablet-based test of selective and orienting attention (t-SOA test) in typical developing children aged 7-10 years. Methods: Two age groups of children, the group 7-8 (7-8 years, 9 girls, 10 boys) and the group 9-10 (9-10 years, 9 girls, 9 boys), performed the t-SOA test on a tablet (Android operating system) and a stylus, as well as the Reaction test of selective attention of the Vienna Test System (RT4-VTS). The criterion validity of the t-SOA test was verified by the RT4-VTS, and the construct validity via an analysis of the effect of age on the results of the t-SOA test. The reliability of the t-SOA test was assessed through internal consistency. Results: The internal consistency of the response time (RT) to the target stimulus was demonstrated to be excellent, Cronbach's α = .944. The mixed linear model with two factors -the central and the spatial (peripheral) cues, showed no significant effect on mean RT. Mean RT, median RT, and the coefficient of variation for RTs (CVRT) in the t-SOA test correlated significantly with analogous test scores of the RT4-VTS test, but not in the case of the number of correct responses, omissions, and commissions. A statistically significant effect of the age group was found for mean RT, median RTs, CVRT, and omission of the t-SOA test. Conclusions: The study demonstrated that the newly constructed t-SOA test may be a valid and reliable tool for assessing the level of visual selective attention of children during middle childhood. The study supported the current suggestion that the assessment of cognitive functions with a touchscreen tablet and a digital stylus is feasible and accepted by school-age children.

Background: Children's creativity and motor competence are expandable factors that are related to convergent and divergent thinking processes.Objective: This study aimed to investigate the effect of games based on divergent and convergent thinking on motor competence and creativity in children aged 7-8 years.Methods: Participants aged 7.41 ± 0.39 years (n = 34) were selected based on inclusion criteria and were divided randomly into three groups (divergent thinking, convergent thinking, and control).Participants performed their group interventions in eighteen training sessions (six weeks period).The nonlinear training approach was used to manipulate divergent thinking and linear training was used in the group of manipulating convergent thinking.Each child completed the Movement Assessment Battery for Children -Second Edition to assess motor competence.The Bertsch Test was used to assess motor creativity.Results: In motor competence, the results revealed significant main effects for groups (p < .001)and time (p < .001) as well as significant groups by time interaction effect (p < .001).The divergent thinking group (M = 32.50) was significantly better than the control group (M = 24.79,p < .001),and the convergent thinking group (M = 28.81,p = .003).In motor creativity, the results revealed significant main effects for groups (p < .001)and time (p < .001) as well as significant groups by time interaction effect (p < .001).The divergent thinking group (M = 13.27,p < .001)and the convergent thinking group (M = 12.36, p = .016)were significantly better than the control group (M = 10.63).However, no significant difference was found between the divergent thinking and convergent thinking groups.Conclusions: Physical education teachers and educators are recommended to use the divergent thinking training approach to promote students' motor competence.Also, simple adjustments in the exercise program in the form of games can help children's motor creativity.However, more research is suggested to explore divergent and convergent learning mechanisms.

Background: Several studies have compared the physical, physiological and anthropometric characteristics according to age and playing position in soccer. However, no studies have researched the comparison of emotional intelligence (EI) levels of soccer players. Objective: The purpose of this study was to compare the EI levels of soccer players in their age and playing position. Methods: A total of 550 male soccer players were divided into four groups according to their age: under-17 (n = 135), under-19 (n = 131), under-21 (n = 144) and 22+ (n = 140) and playing position: goalkeeper (n = 101), defender (n = 159), midfielder (n = 148) and forward (n = 142). EI levels of soccer were evaluated through the Emotional Intelligence Inventory in Sport. Results: Players in the lowest age category showed significantly (p &lt; .001) higher EI level. Moreover, midfielders have also significantly (p = .039) higher EI level than other players. Conclusions: The results of this study indicated that the level of EI varies according to players' age and playing position. These findings might be used for the evaluation of psychological and physiological responses required for soccer-specific performance.

Background: Laser beam devices have been widely used for the assessment of cervical proprioception. However, their reliability for the assessment of repositioning accuracy in patients with chronic neck pain requires further examination. Objective: Examination of test-retest and inter-rater reliability of a laser beam device for the assessment of cervical proprioception in patients with chronic neck pain. Methods: Twenty patients with chronic neck pain were conveniently recruited. The patients performed a head-to-neutral test at four different movement directions (flexion, extension, left and right rotation) and a head-to-target test at two different movement directions (left and right rotation) by wearing on their head a laser beam device. Five trials were performed at each direction. The assessment was performed by two different raters for examining inter-rater reliability. One of the raters reassessed the patients after a one-hour resting period to examine test-retest reliability. Results: Test-retest reliability was found to be moderate to good (intraclass correlation coefficient [ICC] .56-.81, standard error of measurement [SEM] 2.09-5.01 cm, smallest detectable difference [SDD] 5.79-13.87 cm). Inter-rater reliability was found to be moderate to excellent (ICC .59-.92, SEM 1.75-3.27 cm, SDD 4.85-9.05 cm). Conclusions: A laser beam device presented moderate to excellent reproducibility, however relatively high measurement error for assessing cervical proprioception in patients with chronic neck pain.