Dirk Büsch

Influences of competition level, gender, player nationality, career stage and playing position on relative age effects.

Relative age, referring to the chronological age differences between individuals within annually age‐grouped cohorts, is regarded as influential to an athletes development, constraining athletic skill acquisition. While many studies have suggested different mechanisms for this effect, they have typically examined varying sports, precluding an examination of the possible inter‐play between factors. Our three studies try to bridge this gap by investigating several moderators for relative age effects (RAEs) in one sport. Handball is a sport with position‐specific demands, high cultural relevance and a performance context with established developmental structures and levels of representation for males and females. In Study 1, we investigated the influence of competition level and gender on RAEs before adulthood. In Study 2, elite participation, player nationality and stage of career are considered during adulthood. In Study 3, playing position and laterality (i.e., right vs left handedness) are investigated as moderators. Collectively, the results emphasize the complex inter‐play of direct and indirect influences on RAEs in sports, providing evidence toward explaining how RAEs influence the development and maintenance of expertise.

The dimensionality of the Edinburgh Handedness Inventory: An analysis with models of the item response theory

Handedness is frequently measured with sum scores or quotients taken from laterality questionnaires like the Edinburgh Handedness Inventory (EHI). In classical test theory such data cannot be used to confirm either the unidimensionality (i.e., quantitative differentiation with the poles left-handed and right-handed) or multidimensionality (i.e., typological differentiation between left-, right-, and mixed-handers) of this personal characteristic. This study uses item response theory models to test the construct validity of the EHI on an item level in order to gather empirical support for the differentiation of handedness as well as the appropriateness of the items and the response format. The EHI was given to 540 participants (303 male and 237 female) aged 17–37 years. Results of mixed-Rasch analyses revealed that the best model was a two-class solution; that is, left- and right-handers (types) with quantitative differences between persons. Hence, unlike earlier model tests, this rejects both the unidimensionality of the handedness construct and the need to consider so-called mixed-handers. It is proposed that mixed-Rasch analyses should be applied more frequently to test the construct validity of other as well as more extensive handedness questionnaires.

Strength gains by motor imagery with different ratios of physical to mental practice

The purpose of this training study was to determine the magnitude of strength gains following a high-intensity resistance training (i.e., improvement of neuromuscular coordination) that can be achieved by imagery of the respective muscle contraction imagined maximal isometric contraction (IMC training). Prior to the experimental intervention, subjects completed a 4-week standardized strength training program. 3 groups with different combinations of real maximum voluntary contraction (MVC) and mental (IMC) strength training (M75, M50, M25; numbers indicate percentages of mental trials) were compared to a MVC-only training group (M0) and a control condition without strength training (CO). Training sessions (altogether 12) consisted of four sets of two maximal 5-s isometric contractions with 10 s rest between sets of either MVC or IMC training. Task-specific effects of IMC training were tested in four strength exercises commonly used in practical settings (bench pressing, leg pressing, triceps extension, and calf raising). Maximum isometric voluntary contraction force (MVC) was measured before and after the experimental training intervention and again 1 week after cessation of the program. IMC groups (M25, M50, M75) showed slightly smaller increases in MVC (3.0% to 4.2%) than M0 (5.1%), but significantly stronger improvements than CO (−0.2%). Compared to further strength gains in M0 after 1 week (9.4% altogether), IMC groups showed no “delayed” improvement, but the attained training effects remained stable. It is concluded that high-intensity strength training sessions can be partly replaced by IMC training sessions without any considerable reduction of strength gains.

Effects of Resistance Training in Youth Athletes on Muscular Fitness and Athletic Performance: A Conceptual Model for Long-Term Athlete Development

During the stages of long-term athlete development (LTAD), resistance training (RT) is an important means for (i) stimulating athletic development, (ii) tolerating the demands of long-term training and competition, and (iii) inducing long-term health promoting effects that are robust over time and track into adulthood. However, there is a gap in the literature with regards to optimal RT methods during LTAD and how RT is linked to biological age. Thus, the aims of this scoping review were (i) to describe and discuss the effects of RT on muscular fitness and athletic performance in youth athletes, (ii) to introduce a conceptual model on how to appropriately implement different types of RT within LTAD stages, and (iii) to identify research gaps from the existing literature by deducing implications for future research. In general, RT produced small-to-moderate effects on muscular fitness and athletic performance in youth athletes with muscular strength showing the largest improvement. Free weight, complex, and plyometric training appear to be well-suited to improve muscular fitness and athletic performance. In addition, balance training appears to be an important preparatory (facilitating) training program during all stages of LTAD but particularly during the early stages. As youth athletes become more mature, specificity, and intensity of RT methods increase. This scoping review identified research gaps that are summarized in the following and that should be addressed in future studies: (i) to elucidate the influence of gender and biological age on the adaptive potential following RT in youth athletes (especially in females), (ii) to describe RT protocols in more detail (i.e., always report stress and strain-based parameters), and (iii) to examine neuromuscular and tendomuscular adaptations following RT in youth athletes.

The Role of Instability with Plyometric Training in Sub-elite Adolescent Soccer Players

The purpose of this study was to investigate the effects of plyometric training on stable (SPT) vs. highly unstable surfaces (IPT) on athletic performance in adolescent soccer players. 24 male sub-elite soccer players (age: 15±1 years) were assigned to 2 groups performing plyometric training for 8 weeks (2 sessions/week, 90 min each). The SPT group conducted plyometrics on stable and the IPT group on unstable surfaces. Tests included jump performance (countermovement jump [CMJ] height, drop jump [DJ] height, DJ performance index), sprint time, agility and balance. Statistical analysis revealed significant main effects of time for CMJ height (p<0.01, f=1.44), DJ height (p<0.01, f=0.62), DJ performance index (p<0.05, f=0.60), 0-10-m sprint time (p<0.05, f=0.58), agility (p<0.01, f=1.15) and balance (p<0.05, 0.46≤f≤1.36). Additionally, a Training group×Time interaction was found for CMJ height (p<0.01, f=0.66) in favor of the SPT group. Following 8 weeks of training, similar improvements in speed, agility and balance were observed in the IPT and SPT groups. However, the performance of IPT appears to be less effective for increasing CMJ height compared to SPT. It is thus recommended that coaches use SPT if the goal is to improve jump performance.

Your fate is in your hands? Handedness, digit ratio (2D:4D), and selection to a national talent development system

Over the past decade a small evidence base has highlighted the potential importance of seemingly innocuous variables related to ones hands, such as hand dominance and the relative length of the second and fourth digits (2D:4D ratio), to success in sport. This study compared 2D:4D digit ratio and handedness among handball players selected to advance in a national talent development system with those not selected. Participants included 480 youth handball players (240 females and 240 males) being considered as part of the talent selection programme for the German Youth National team. Hand dominance and digit ratio were compared to age-matched control data using standard t-tests. There was a greater proportion of left-handers compared to the normal population in males but not in females. There was also a lower digit ratio in both females and males. However, there were no differences between those selected for the next stage of talent development and those not selected on either handedness or digit ratio. These results add support for general effects for both digit ratio and handedness in elite handball; however, these factors seem inadequate to explain talent selection decisions at this level.

Das Lateral Preference Inventory: Itemhomogenität der deutschen Version

Zusammenfassung. Das Lateral Preference Inventory (LPI, Coren, 1993) soll die bevorzugte Seite fur die Dimensionen Handigkeit, Fusigkeit, Augigkeit und Ohrigkeit ermitteln. In dieser Pilotstudie wurde mit N = 540 Versuchspersonen (n = 303 mannlich, n = 237 weiblich) im Alter von 17 bis 37 Jahren (M = 22.1, SD = 2.7) die Konstruktvaliditat auf Itemebene (Itemhomogenitat) der deutschen Version des LPI untersucht. Die Seitigkeitsdimensionen wurden inferenzstatistisch mit dem ordinalen Mixed-Rasch-Modell und dem latenten Klassenmodell uberpruft. Erst die Eliminierung der Antwortkategorie „egal” fuhrt zu einer zufriedenstellenden Konstruktvaliditat auf Itemebene. Fur die Seitigkeitsdimensionen lasst sich jeweils eine 2-Klassen-Losung ermitteln, mit der Personen in Rechtstypen und Mischtypen eingeteilt werden konnen. Abschliesend werden Empfehlungen zur Verbesserung des LPI aufgezeigt.

Applications of Generalized Rasch Models in the Sport, Exercise, and the Motor Domains

This chapter provides an overview of the applications of Rasch models (RMs) and their generalizations in the sport, exercise, and motor domains. More specifically, it covers the main areas where Rasch analyses advanced the knowledge base on issues such as (1) examining and developing state and trait-type measures such as motivation for physical activity, anxiety and precompetition anxiety, flow, goal orientation, and running discomfort, or other measures like self-concept or fan identification, (2) testing the stability of introspective and actual measures, (3) testing accumulation of perceived exertion during gradual effort increase, and (4) examining motor abilities, detecting motor components, and strategies used in motor control and development.

Anwendungen probabilistischer Modelle in der Sportpsychologie

Zusammenfassung. Ziel dieses Kurzbeitrags ist ein Uberblick uber die wichtigsten probabilistischen Testmodelle und ihre wichtigsten Anwendungen in der Sportpsychologie und Bewegungswissenschaft. Seit der Publikation des sogenannten eindimensionalen Rasch-Modells (Rasch, 1960) sind zahlreiche probabilistische Modelle entwickelt worden, die es erlauben, auch komplexe Fragestellungen zu uberprufen.

Perceptual-cognitive expertise of handball coaches in their young and middle adult years

ABSTRACT There is little research investigating the maintenance of perceptual-cognitive expertise in general and even less comparing coaches of different ages. The aim of this study was to test for perceptual-cognitive differences between age groups, licence levels, and their interaction. This study investigated differences in skilled performance between young and middle-aged coaches of three different skill levels. Participants performed an accuracy-oriented pattern recall (mean distance in pixel) and a time-oriented flicker test (mean detection time in ms). There were some significant differences between age groups and between skill groups for both tests, but no interactions. For the pattern recall test, the effect sizes were larger for skill level differences, while for the flicker test effects were larger for ageing. These results suggest coaches are able to maintain accuracy skills better than reaction timed tasks. This is in line with findings on speeded performance in general populations, which show declines with age. Moreover, results also support findings on perceptual expertise in skills where accuracy was important.