Association between SARS-COV-2 infection and muscle strain injury occurrence in elite male football players: a prospective study of 29 weeks including three teams from the Belgian professional football league.

Objectives: The aim of this study was to investigate the association between SARS-CoV-2 infection and muscle strain injury in elite athletes.

Methods: A prospective cohort study in three Belgian professional male football teams was performed during the first half of the 2020-2021 season (June 2020-January 2021). Injury data were collected using established surveillance methods.

Multilevel modelling of longitudinal changes in isokinetic knee extensor and flexor strength in adolescent soccer players.

The purpose of the study was to model the longitudinal development of knee extension (KE) and flexion (KF) strength in adolescent soccer players. A mixed-longitudinal sample composed of 67 soccer players aged 11.0-13.

Developmental Changes in Isometric Strength: Longitudinal Study in Adolescent Soccer Players.

This study aimed to examine longitudinal changes in isometric strength of the knee extensors (ImKE) and knee flexors (ImKF) at 30° and 60°. The sample was composed of 67 players aged 11.0-13.

Multivariate Relationships among Morphology, Fitness and Motor Coordination in Prepubertal Girls.

Motor coordination and physical fitness are multidimensional concepts which cannot be reduced to a single variable. This study evaluated multivariate relationships among morphology, physical fitness and motor coordination in 74 pre-pubertal girls 8.0-8.

Correction to: Tanner-Whitehouse Skeletal Ages in Male Youth Soccer Players: TW2 or TW3?

An Online First version of this article was made available online at https://link.springer.com/article/10.

Associations Between Objectively Assessed Components of Physical Activity and Health-Related Fitness in 10- to 14-Year-Old Children.

Background: Our aim was to investigate the association between different components of physical activity (PA) and health-related fitness in 10-to 14-year-old children.

Methods: 241 children were recruited from 15 primary and 15 secondary schools. PA was assessed using the SenseWear Mini and an electronic diary.

Temporal patterns of physical activity and sedentary behavior in 10-14 year-old children on weekdays.

Background: An important but often ignored aspect of physical activity (PA) and sedentary behavior (SB) is the chronological succession of activities, or temporal pattern. The main purposes of this study were (1) to investigate when certain types of PA and SB compete against each other during the course of the day and (2) compare intensity- and domain-specific activity levels during different day-segments.

Methods: The study sample consists of 211 children aged 10-14, recruited from 15 primary and 15 secondary schools.

A retrospective study on anthropometrical, physical fitness, and motor coordination characteristics that influence dropout, contract status, and first-team playing time in high-level soccer players aged eight to eighteen years.

The goal of this article was twofold, and a 2-study approach was conducted. The first study aimed to expose the anthropometrical, physical performance, and motor coordination characteristics that influence dropout from a high-level soccer training program in players aged 8-16 years. The mixed-longitudinal sample included 388 Belgian youth soccer players who were assigned to either a "club group" or a "dropout group.

A longitudinal study investigating the stability of anthropometry and soccer-specific endurance in pubertal high-level youth soccer players.

We investigated the evolution and stability of anthropometric and soccer-specific endurance characteristics of 42 high-level, pubertal soccer players with high, average and low yo-yo intermittent recovery test level 1 (YYIR1) baseline performances over two and four years. The rates of improvement were calculated for each performance group, and intra-class correlations were used to verify short- and long-term stability. The main finding was that after two and four years, the magnitudes of the differences at baseline were reduced, although players with high YYIR1 baseline performance still covered the largest distance (e.

Anthropometric characteristics, physical fitness and motor coordination of 9 to 11 year old children participating in a wide range of sports.

Objectives: The aim of this study was to investigate to what extent 9 to 11 year old children participating in a specific sport already exhibit a specific anthropometric, physical fitness and motor coordination profile, in line with the requirements of that particular sport. In addition, the profiles in children with a different training volume were compared and possible differences in training hours per week between children from a low, moderate, and high level of physical fitness and motor coordination were investigated.

Methods And Results: Data of 620 children, 347 boys and 273 girls, who participated in the Flemish Sports Compass were used.

Intensity- and Domain-Specific Levels of Physical Activity and Sedentary Behavior in 10- to 14-Year-Old Children.

Background: to investigate levels of physical activity (PA) and sedentary behavior (SB) in 10- to 14-year-olds and to determine PA differences between week-weekend days, genders and school stages.

Methods: 241 children were recruited from 15 primary and 15 secondary schools. PA was assessed for 7 days using the SenseWear Mini Armband and an electronic diary.

Measuring dwell time percentage from head-mounted eye-tracking data--comparison of a frame-by-frame and a fixation-by-fixation analysis.

Although analysing software for eye-tracking data has significantly improved in the past decades, the analysis of gaze behaviour recorded with head-mounted devices is still challenging and time-consuming. Therefore, new methods have to be tested to reduce the analysis workload while maintaining accuracy and reliability. In this article, dwell time percentages to six areas of interest (AOIs), of six participants cycling on four different roads, were analysed both frame-by-frame and in a 'fixation-by-fixation' manner.

Stature and jumping height are required in female volleyball, but motor coordination is a key factor for future elite success.

It was hypothesized that differences in anthropometry, physical performance, and motor coordination would be found between Belgian elite and sub-elite level female volleyball players using a retrospective analysis of test results gathered over a 5-year period. The test sample in this study consisted of 21 young female volleyball players (15.3 ± 1.

Multilevel Development Models of Explosive Leg Power in High-Level Soccer Players.

Purpose: The aim of the present study was to model developmental changes in explosive power based on the contribution of chronological age, anthropometrical characteristics, motor coordination parameters, and flexibility.

Methods: Two different longitudinal, multilevel models were obtained to predict countermovement jump (CMJ) and standing broad jump (SBJ) performance in 356 high-level, youth soccer players, age 11-14 yr at baseline. Biological maturity status was estimated (age at peak height velocity [APHV]), and variation in the development of explosive power was examined based on three maturity groups (APHV; earliest < P33, P33 < average < P66, latest > P66).

Generic anthropometric and performance characteristics among elite adolescent boys in nine different sports.

The aim of the present study was to evaluate the Flemish Sports Compass (FSC), a non-sport-specific generic testing battery. It was hypothesised that a set of 22 tests would have sufficient discriminant power to allocate athletes to their own sport based on a unique combination of test scores. First, discriminant analyses were applied to the 22 tests of anthropometry, physical fitness and motor coordination in 141 boys under age 18 (16.

Cycling around a curve: the effect of cycling speed on steering and gaze behavior.

Although it is generally accepted that visual information guides steering, it is still unclear whether a curvature matching strategy or a 'look where you are going' strategy is used while steering through a curved road. The current experiment investigated to what extent the existing models for curve driving also apply to cycling around a curve, and tested the influence of cycling speed on steering and gaze behavior. Twenty-five participants were asked to cycle through a semicircular lane three consecutive times at three different speeds while staying in the center of the lane.

Motor competence assessment in children: convergent and discriminant validity between the BOT-2 Short Form and KTK testing batteries.

This study investigated convergent and discriminant validity between two motor competence assessment instruments in 2485 Flemish children: the Bruininks-Oseretsky Test of Motor Proficiency 2 Short Form (BOT-2 Short Form) and the KörperKoördinationsTest für Kinder (KTK). A Pearson correlation assessed the relationship between BOT-2 Short Form total, gross and fine motor composite scores and KTK Motor Quotient in three age cohorts (6-7, 8-9, 10-11 years). Crosstabs were used to measure agreement in classification in children scoring below percentile 5 and 15 and above percentile 85 and 95.

Modeling developmental changes in yo-yo intermittent recovery test level 1 in elite pubertal soccer players.

Purpose: To model the development of soccer-specific aerobic performance, assessed by the Yo-Yo Intermittent Recovery Test Level 1 in 162 elite pubertal soccer players, age 11-14 y at baseline.

Methods: Longitudinal multilevel modeling analyses comprised predictors related to growth (chronological age, body size [height and weight] and composition [fat mass, fat-free mass]), and motor coordination [3 KÖrperkoordination Test für Kinder subtests: jumping sideways, moving sideways, backward balancing] and estimated biological-maturation groups (earliest [percentile 66]).

Results: The best-fitting model on soccer-specific aerobic performance could be expressed as -3639.

A longitudinal study of gross motor coordination and weight status in children.

Objective: This longitudinal study investigated the interrelationship between children's weight status and level of gross motor coordination over time, taking baseline physical activity (PA) into account as a possible mediator.

Methods: Baseline measurements were collected in 2517 children (5-13 years, 52.8% boys), including (1) body height and weight to calculate body mass index (BMI) z-scores, (2) gross motor coordination using the Körperkoordinationstest für Kinder (KTK), (3) total PA estimated by a questionnaire.

Reliability and validity of the Yo-Yo intermittent recovery test level 1 in young soccer players.

The present study investigated the test-retest reliability from the Yo-Yo IR1 (distance and heart rate responses), and the ability of the Yo-Yo IR1 to differentiate between elite and non-elite youth soccer players. A total of 228 youth soccer players (11-17 years) participated: 78 non-elite players to examine the test-retest reliability within 1 week, added with 150 elite players to investigate the construct validity. The main finding was that the distance covered was adequately reproducible in the youngest age groups (U13 and U15) and highly reproducible in the oldest age group (U17).

Changes in physical fitness and sports participation among children with different levels of motor competence: a 2-year longitudinal study.

The goal of this study was to investigate differences in physical fitness and sports participation over 2 years in children with relatively high, average, and low motor competence. Physical fitness and gross motor coordination of 501 children between 6-10 years were measured at baseline and baseline+2 years. The sample compromised 2 age cohorts: 6.

Differences in biological maturation, anthropometry and physical performance between playing positions in youth team handball.

It was the goal of this cross-sectional study to examine differences in maturity, anthropometry and physical performance between youth handball players across different playing positions (i.e. goalkeeper, back, pivot and wing).

Objectively-determined intensity- and domain-specific physical activity and sedentary behavior in relation to percent body fat.

Background & Aims: This study examined the independent and joint associations of overall, intensity-specific and domain-specific physical activity and sedentary behavior with bioelectrical impedance-determined percent body fat.

Methods: Physical activity was measured in 442 Flemish adults (41.4 ± 9.