No abstract

This study aimed to determine if the Körperkoordinationstest für Kinder (KTK) remained a valid assessment of motor competence following the removal of the hopping for height subtest (KTK3). Children (n = 2479) aged 6–11 years completed all KTK subtests (KTK4) and motor quotient sum scores (MQS) were determined for the KTK3 and KTK4. Classifications were established as MQS below percentile 5 (P5), MQS between percentile 5–15 (P15), MQS between percentile 15–50 (P15–50), MQS between percentile 50–85 (P50–85), MQS between percentile 85–95 (P85), and MQS higher than percentile 95 (P95). Pearson’s correlation (r = .97) and cross-tabs (Chi2 = 6822.53, p < .001; Kappa = 0.72) identified substantial agreement overall between the KTK3 and KTK4. However, when classified into separate age and gender categories, poor agreement (< 60%) was found in girls: P15 at 8–11 years and P85 at 6–7 years; and in boys: P5 and P15 at 6 years, P85 at 8 years, and P15 at 10 years. Researchers should consider these findings when selecting which KTK protocol to use.

Introduction: Assessments of executive functions (EFs) with varying levels of perceptual information or action fidelity are common talent-diagnostic tools in soccer, yet their validity still has to be established. Therefore, a longitudinal development of EFs in high-level players to understand their relationship with increased exposure to training is required. Methods: A total of 304 high-performing male youth soccer players (10–21 years old) in Germany were assessed across three seasons on various sport-specific and non-sport-specific cognitive functioning assessments. Results: The posterior means (90% highest posterior density) of random slopes indicated that both abilities predominantly developed between 10 and 15 years of age. A plateau was apparent for domain-specific abilities during adolescence, whereas domain-generic abilities improved into young adulthood. Conclusion: The developmental trajectories of soccer players’ EFs follow the general populations’ despite long-term exposure to soccer-specific training and game play. This brings into question the relationship between high-level experience and EFs and renders including EFs in talent identification questionable.

The purpose of this study was to examine to what extent the physical match performance of professional soccer players is both position and player specific. First, official match data from the 2019/20 German Bundesliga season was used to search for players that met the inclusion criteria of playing a minimum of four entire matches in at least two different playing positions. Overall, 25 players met the criteria prior to the COVID-19 induced break, playing a minimum of eight matches. Second, the physical match performance of these players was analyzed separately for each position they played. The following four parameters were captured: total distance, high-intensity distance, sprinting distance, and accelerations. Third, the 25 players’ physical match performance data was then compared to normative data for each position they played to understand whether players adapted their physical performance (position dependent), or maintained their performance regardless of which position they were assigned to (position independent). When switching the position, the change in physical match performance of the respective players could be explained by 44–58% through the normative positional data. Moreover, there existed large individual differences in the way players adapted or maintained their performance when acting in different positions. Coaches and practitioners should be aware that some professional soccer players will likely incur differences in the composition of physical match performance when switching positions and therefore should pay special consideration for such differences in the training and recovery process of these players.