This study evaluates accelerometer performance of three new state of the art smartphones and focuses on accuracy. The motivating research question was whether accelerator accuracy obtained with these off-the-shelf modern smartphone accelerometers was or was not statistically different from that of a gold-standard reference system. We predicted that the accuracy of the three modern smartphone accelerometers in human movement data acquisition do not differ from that of the Vicon MX motion capture system. To test this prediction, we investigated the comparative performance of three different commercially available current generation smartphone accelerometers among themselves and to a gold-standard Vicon MX motion capture system. A single subject design was implemented for this study. Pearson’s correlation coefficients^® were calculated to verify the validity of the smartphones’ accelerometer data against that of the Vicon MX motion capture system. The Intraclass Correlation Coefficient (ICC) was used to assess the smartphones’ accelerometer performance reliability compared to that of the Vicon MX motion capture system. Results demonstrated that (a) the tested smartphone accelerometers are valid and reliable devices for estimating accelerations and (b) there were not significant differences among the three current generation smartphones and the Vicon MX motion capture system’s mean acceleration data. This evidence indicates how well recent generation smartphone accelerometer sensors are capable of measuring human body motion. This study, which bridges a significant information gap between the accuracy of accelerometers measured close to production and their accuracy in actual smartphone research, should be interpreted within the confines of its scope, limitations and strengths. Further research is warranted to validate our arguments, suggestions, and results, since this is the first study on this topic.

This paper offers an in-depth exploration of the intricate relationship between environmental factors and autism spectrum disorder (ASD), with a special emphasis on seasonality. It reviews existing research, providing a comprehensive summary of findings and highlighting the multifaceted dimensions of several environmental factors influencing the etiology of ASD. The discussion encompasses various elements, including birth months, maternal health, dietary choices, and vitamin D deficiency, delving into the intricate interplay of seasonality with environmental influences such as viral infections and solar radiation. The present study raises essential questions regarding the timing of environmental influences and the factors contributing to the rising prevalence of ASD. Ultimately, it underscores the need for future epidemiological research to incorporate more extensive investigations of environmental risk factors and employ advanced statistical analyses. This comprehensive overview contributes to a deeper understanding of how environmental factors, particularly seasonality, may be linked to the occurrence of ASD and its increasing prevalence, recognizing the multifaceted and diverse nature of these interactions.

In the present study, 96 teams’ performances across 48 matches in the group stage of the FIFA Club World Cup 2025 were analyzed. Teams scoring first won 62.5% of matches (p < 0.05), while goals were evenly distributed between halves (p > 0.05) and showed marginal variation across six 15 min intervals, peaking near the 30–45 and 75–90 min marks. Parametric analyses revealed a significant effect of match outcome on possession, with winning teams exhibiting higher average possession (53.3%) compared to losing and drawing teams. Non-parametric analyses identified significant differences between match outcomes for goals scored, attempts at goal, total and completed passes, pass completion rate, defensive line breaks, receptions in the final third, ball progressions, defensive pressures, and total distance covered. Winning teams scored more goals and registered more attempts on target than losing teams, although some metrics showed no significant difference between wins and draws. Logistic regression analysis identified attempts at goal on target, defensive pressures, total completed passes, total distance covered, and receptions in the final third as significant predictors of match success (AUC = 0.85), correctly classifying 80.2% of match outcomes. These results emphasized the crucial role of offensive accuracy and possession dominance in achieving success in elite football.

The aim of this study was to assess the validity and intra-session reliability of the MyJump 2 smartphone application for evaluating countermovement jump (CMJ) and squat jump (SJ) performance in youth soccer players using the Chronojump contact mat system as a reference. Twenty-one male soccer players from an elite team (U14–U19) were randomly selected to participate in countermovement jump (CMJ) and squat jump (SJ) assessments, with jump heights recorded simultaneously by both systems. Validity was examined through Bland–Altman analysis, Pearson and Spearman correlations and linear regression. Reliability was assessed using intraclass correlation coefficients (ICC), standard error of measurement (SEM) and Bland–Altman test–retest analysis. Results revealed minor systematic overestimation by MyJump 2 (+0.943 cm for CMJ; +1.042 cm for SJ). Strong correlations were found between MyJump 2 and Chronojump (r = 0.972 for CMJ; r = 0.955 for SJ), while ICCs exceeded 0.97 for both jump types, indicating excellent reliability. These findings support MyJump 2 as a valid and reliable alternative for vertical jump testing in adolescent and junior soccer players as an accessible and suitable tool for field-based performance monitoring regarding vertical jumping ability.

In upright standing, the human foot sole is the only point of contact with the ground conveying information about the pressure distribution under the feet. We examined how the altered somatosensory input from the plantar foot receptors, when standing on a soft surface, affects the subjective estimation of the earth vertical in different sensory contexts. Twelve (12) healthy young females (mean age: 21.8 ± 2.4 years) adjusted the orientation of a visual line (35 × 1.5 cm) representing the roll orientation of a hand-held (attached on a 24.9 × 4 cm cylinder) or head-attached electromagnetic tracking sensor (Nest of Birds, Ascension Technologies Inc., VT. USA, 60 Hz) under two visual conditions (eyes open, eyes closed) while standing on a soft or firm surface. The mean absolute (accuracy) and variable (precision) error in the verticality estimate was depicted in the sensor's roll deviation from the gravitational vertical. The accuracy and the precision of the estimate decreased in the absence of vision, while standing on the soft surface and when the estimate was provided by an active hand rather than head rotation. The surface effect was significant only in the absence of vision and when the estimate was provided by the hand. The contribution of the plantar foot mechanoreceptors to gravity perception is sensory context dependent. Perception of the earth vertical is more accurate when estimated by active head rotation due to the integration of the vestibular and neck proprioceptive afferents.

This study examined acute pre- to post-match changes in perceived mental fatigue, subjective workload, and psychomotor performance in professional male soccer players, and whether cognitive changes were associated with GPS-derived external-load metrics, match outcome, and playing position. The dataset comprised 101 player–match measurements from 40 elite players, with paired pre–post psychomotor assessments yielding n = 202 total measurements. Pre–post comparisons were analysed using repeated-measures ANOVA, supplemented by linear mixed-effects models with a random intercept for player. Soccer matches produced large increases in perceived exertion, mental fatigue, mental demand, physical demand, and effort (all p < 0.001), and significant deteriorations in reaction time, accuracy, processing speed, and response variability (all p ≤ 0.005), confirmed in the mixed-effects analyses (all p ≤ 0.014). In the initial player–match-level analyses, high-intensity accelerations (>3 m·s⁻²) were weakly associated with greater Δreaction-time slowing (r = 0.203), increased response variability (r = 0.276), and reduced Rate Correct Score (r = −0.242), while high metabolic load distance was weakly associated with post-match perceived mental fatigue but not with psychomotor-performance changes. One-way ANOVAs indicated greater post-match psychomotor decrements following losses than draws. Once within-player dependence was modelled, the effects of match outcome, playing position, and most external-load metrics were attenuated, except for a residual match-outcome effect on accuracy and a high-intensity deceleration effect on accuracy. These findings indicate that competitive soccer match play is followed by acute psychomotor-performance decrements and increased perceived mental fatigue, whereas the contributions of mechanical load, match outcome, and playing position appear modest and partly reflect stable between-player differences.