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1.
Abstract

This study examined the disturbing effects of relative age on the talent identification process in the talent development programme of the German Football Association. The bias in the selection rate was examined via the extent of relative age effects. The bias in motor performance diagnostics was analysed by comparing the motor performance of selected players with normal motor development. The mechanisms underlying the relative age biases in motor performance were examined by modelling the direct and indirect effects of relative age on single motor performance tests for sprint, running agility, dribbling and ball passing and control. Data from 10,130 selected football players from the U12 to U15 age groups were collected in autumn 2010. The birth distribution differed significantly from the reference population with approximately 61% of the players born in the first half of the year. The selection probability was approximately two times higher for players born in the first quarter of the year than for players born in the last quarter. Revised motor performance diagnostics showed better results on average for relatively younger players. Path analysis revealed significant direct and indirect relative age effects for physiologically demanding tests and almost no effects for technically demanding tests. Large sample sizes allowed high resolution in relative age with additional informational content and multivariate modelling of the complex relationships among relative age, physical development and motor performance. The results are discussed on how relative age affects the effectiveness and fairness of talent identification and development processes.  相似文献   

2.
ABSTRACT

We quantified the peak age of judokas during the World Championships (WC) and Olympic Games (OG) according to sex, weight category and competitive achievement and determined the relationship between competition year and athlete age. A retrospective study including 12,005 athletes who took part in the last 16 WC and 6 OG. Athletes were divided by sex, weight category and competitive achievement. Overall, females were younger than males, and older athletes competed at the OG compared to the WC. A weight category effect was also observed, with lighter athletes being younger than heavier athletes (p < 0.05). A competitive achievement effect was found for females, with athletes being defeated in the eliminatory phases being younger than those advancing further in the competitions (p < 0.05). Significant associations (p < 0.05) were shown between competition year and age category for males at the WC and for females at both the WC and OG. In general, lighter athletes are younger than heavier ones (p < 0.05). No difference in age was found between males concerning their competitive achievement in WC and OG, whereas younger females are defeated in the eliminatory phases (p < 0.05).  相似文献   

3.
Abstract

Nine males and nine females were used as subjects to test the null hypothesis that there would be no significant differences between the performance of college age males and females on three motor tasks. Star tracing, tapping, and rotary pursuit were the tasks used under two conditions: (a) while looking at a mirror that would cause a reversal effect, and (b) under standard conditions without looking at a mirror. Results revealed no differences between males and females on the tasks performed without a mirror. However, the females performed significantly better on the same tasks while looking at a mirror.  相似文献   

4.
Abstract

It is well documented that simple reaction time (RT) varies inversely with stimulus intensity, but there is disagreement as to which stimulus modality produces the fastest simple RT. An investigation was conducted to equate two stimulus modalities, auditory (A) and electrocutaneous (EC), using varying stimulus intensities in a simple RT protocol. A second investigation was then conducted to examine neuromotor characteristics of stimulus-evoked responses using previously equated A and EC stimuli of varying intensity from the first investigation. Results showed that RT, premotor time (PMT), and motor time (MT) were all inversely related to stimulus intensity, while maximum displacement (MAXD) was directly related to stimulus intensity, and movement time was not affected by stimulus intensity. We conclude that: (a) both central and peripheral components of RT are altered by varying stimulus intensities, and (b) rapid movements are enhanced by increasing stimulus intensity.  相似文献   

5.
Abstract

The present study was designed to examine the effects of age, modeling and verbal self-instruction on children's performance of a sequential motor task. Eighty-four children between the ages of 4–0 and 5–11 years and 84 children between the ages of 7–0 and 8–11 years were randomly assigned to one of six instructional conditions in a 2 × 3 × 2 (age × model type × verbal self-instruction) factorial design. Results revealed that older children performed better than younger children on motor, verbal-cognitive, and attentional measures. More importantly, an age by model type interaction revealed that model effectiveness depended on the age of the observer as well as the type of model observed. Specifically, 7- and 8-year-old children performed equally well after observing either a silent or verbal model, while the 4- and 5-year-olds performed best under a verbal model only. The absence of verbal self-instructional effects was attributed to task difficulty, information processing capabilities and methodological procedures. In general, the results supported the notion that developmental factors play a critical role in the modeling process, and both theoretical and practical implications are outlined.  相似文献   

6.
Abstract

The purpose of the present experiment was to replicate and extend previous developmental modeling research by examining the qualitative as well as quantitative aspects of motor performance. Eighty females of two age groups (5–0 to 6–6 and 7–6 to 9–0 years) were randomly assigned to conditions within a 2 × 2 × 2 (Age x Model Type x Rehearsal) factorial design. Children received either verbal instructions only (no model) or a visual demonstration with experimenter-given verbal cues (verbal model) of a five-part dance skill sequence. Children were either prompted to verbally rehearse before skill execution or merely asked to reproduce the sequence without prompting. Both quantitative (order) and qualitative (form) performances were assessed. Results revealed a significant age main effect for both order and form performance, with older children performing better than younger children. A model type main effect was also found for both order and form performance. The verbal model condition produced better qualitative performance, whereas the no model condition resulted in better quantitative scores. These results are discussed in terms of differential coding strategies that may influence task components in modeling.  相似文献   

7.
Abstract

The purpose of this study was to compare reaction time (RT) and fractionated RT components (premotor and motor times) between normal and postcontraction conditions. Twelve participants performed 20 trials each of control and postcontraction RT conditions. For the control condition, participants executed a learned, rapid, knee-extension contraction response to an auditory stimulus. The postcontraction condition was identical to the control condition except that the participants performed a 3-s isometric contraction of the knee extensor muscles prior to an auditory stimulus. Muscle activity was recorded from the quadriceps muscle group. Results indicated that the postcontraction condition was significantly faster than the control condition for the average RT, premotor time, and motor time. It was concluded that reaction time, processing time, and muscle contraction time for a learned task could be significantly reduced following an isometric contraction.  相似文献   

8.
Abstract

This study examined the interrelationships among perceived physical competence, motor competence, and participation in organized sport in young children. Males and females in Grades K through 4 (n = 250) were given The Perceived Competence Scale for Children (Harter, 1979) or The Pictoral Scale for Perceived Competence and Social Acceptance for Young Children (Harter, Pike, Efron, Chao, & Bierer, 1983), a 9-item motor competence assessment battery, and a questionnaire regarding their participation in sport. Results revealed that perceived physical competence for children in these grade levels was not significantly related to their participation in organized sport programs. Motor competence was significantly related to participation in that participants in organized sport programs performed selected gross motor tasks better than did nonparticipants. Further, children's reported perceptions of physical competence were significantly related to their demonstrated motor competence. Discussion focused on the theoretical and practical implications of the results.  相似文献   

9.
Abstract

This study aimed to determine indicators of sailing performance in 2 (age) groups of youth sailors by investigating the anthropometric, physical and motor coordination differences and factors discriminating between elite and non-elite male optimist sailors and young dynamic hikers. Anthropometric measurements from 23 optimist sailors (mean ± SD age = 12.3 ± 1.4 years) and 24 dynamic youth hikers (i.e. Laser 4.7, Laser radial and Europe sailors <18 years who have to sail the boat in a very dynamic manner, due to a high sailor to yacht weight ratio) (mean ± SD age = 16.5 ± 1.6 years) were conducted. They performed a physical fitness test battery (EUROFIT), motor coordination test battery (Körperkoordinationstest für Kinder) and the Bucket test. Both groups of sailors were divided into two subgroups (i.e. elites and non-elites) based on sailing expertise. The significant differences, taking biological maturation into account and factors discriminating between elite and non-elite optimist sailors and dynamic hikers were explored by means of multivariate analysis of covariance and discriminant analysis, respectively. The main results indicated that 100.0% of elite optimist sailors and 88.9% of elite dynamic hikers could be correctly classified by means of two motor coordination tests (i.e. side step and side jump) and Bucket test, respectively. As such, strength- and speed-oriented motor coordination and isometric knee-extension strength endurance can be identified as indicators of sailing performance in young optimist and dynamic youth sailors, respectively. Therefore, we emphasise the importance of motor coordination skill training in optimist sailors (<15 years) and maximum strength training later on (>15 years) in order to increase their isometric knee-extension strength endurance.  相似文献   

10.

Purpose: This exploratory study examined the notion of Seefeldt's (1980) hypothesized motor skill “proficiency barrier” related to composite levels of health-related physical fitness (HRF) in young adults. Method: A motor skill competence (MSC) index composed of maximum throwing and kicking speed and jumping distance in 187 young adults aged 18 to 25 years old was evaluated against a composite index of 5 health-related fitness (HRF) test scores. MSC (high, moderate, and low) and HRF indexes (good, fair, and poor) were categorized according to normative fitness percentile ranges. 2 separate 3-way chi-square analyses were conducted to determine the probabilities of skill predicting fitness and fitness predicting skill. Results: Most correlations among HRF and MSC variables by gender demonstrated low-to-moderate positive correlations in both men (12/15; r = .23–.58) and women (14/15; r = .21–.53). Chi-square analyses for the total sample, using composite indexes, demonstrated statistically significant predictive models, χ 2 (1, N = 187) = 66.99, p < .001, Cramer's V = .42. Only 3.1% of low-skilled (2 of 65) individuals were classified as having a “good” HRF. Only 1 participant (out of 65) who demonstrated high MSC was classified as having “poor” HRF (1.5%). Conclusion: Although individual correlations among individual MSC and HRF measures were low to moderate, these data provide indirect evidence for the possibility of a motor skill “proficiency barrier” as indicated by low composite HRF levels. This study may generate future research to address the proficiency barrier hypothesis in youth as well as adults.  相似文献   

11.
Abstract

Performance differences between males and females have been attributed to both biological and cultural factors, although the relative significance of each has not been ascertained. Differences in body fatness between males and females has been frequently mentioned as one biological factor responsible for variations in physical performance. In children, it has been shown that boys exhibit slightly higher performance levels than girls until adolescence, when the differences favoring the boys become greater. The purpose of this study was to investigate the relationship between selected physical performance tests and body fatness in preadolescent boys and girls. Measures of age, height, weight, skinfold thicknesses at two sites, and performance scores on the vertical jump, standing broad jump, modified pullup, 40-yard dash, and 400-yard run were obtained on 563 elementary school children. The results of a one-way ANOVA indicated that there was a significant difference between boys and girls on all of the physical performance tests. Although the boys were slightly taller and heavier and scored better than the girls on the performance tests, there was no significant difference between the sexes in the sum of two skinfolds. Separate regression equations for the sum of two skinfolds by performance on each test indicated that, with the exception of the modified pullup test, body fatness was only marginally related to performance. These findings indicated that, although inversely related to the ability to move the total body weight, body fatness was of minimal importance in explaining performance differences between young boys and girls.  相似文献   

12.
Purpose: A large pool of evidence supports the beneficial effect of an external focus of attention on motor skill performance in adults. In children, this effect has been studied less and results are inconclusive. Importantly, individual differences are often not taken into account. We investigated the role of working memory, conscious motor control, and task-specific focus preferences on performance with an internal and external focus of attention in children. Methods: Twenty-five children practiced a golf putting task in both an internal focus condition and external focus condition. Performance was defined as the average distance toward the hole in 3 blocks of 10 trials. Task-specific focus preference was determined by asking how much effort it took to apply the instruction in each condition. In addition, working memory capacity and conscious motor control were assessed. Results: Children improved performance in both the internal focus condition and external focus condition (?p2 = .47), with no difference between conditions (?p2 = .01). Task-specific focus preference was the only factor moderately related to the difference between performance with an internal focus and performance with an external focus (r = .56), indicating better performance for the preferred instruction in Block 3. Conclusion: Children can benefit from instruction with both an internal and external focus of attention to improve short-term motor performance. Individual, task-specific focus preference influenced the effect of the instructions, with children performing better with their preferred focus. The results highlight that individual differences are a key factor in the effectiveness in children’s motor performance. The precise mechanisms underpinning this effect warrant further research.  相似文献   

13.
Abstract

Boxing is a sport that comprises a wide variety of integrated offensive, defensive and counter-attack skills performed in an unpredictable environment. Mastering the variety of complex motor skills (CMS) that are required in a boxing match allows the player to employ the best motor performance in most positions of the actual game. This study aimed to assess the associations between implementing CMS versus simple motor skill (SMS) training and the subsequent changes in physical, technical and technical performance effectiveness (TPE) variables in junior boxers. We employed an experimental design that comprised two groups (each 20 males, mean age = 15.22±0.62 years). For 12 weeks, intervention boxers received CMS training, while controls received traditional SMS training. Physical, technical and TPE variables were measured before and after the training programs. Although the two groups were of similar abilities at baseline, there were statistically significant differences (P<0.05) between the intervention and control boxers in the post measures, to the advantage of the intervention group. In terms of absolute (i.e. differences in) or relative (i.e. ratios of) improvements, the intervention group exhibited more favourable values across the variables, and better performance. Developing CMS of junior boxers could contribute positively to their physical and technical abilities, and enhance their TPE.  相似文献   

14.
Abstract

Little research has investigated the observational learning process from a developmental perspective. The purpose of this study was to extend previous research by considering two factors: performance versus learning and sequencing versus form scores. Children 'N = 60) comprising two age groups (5-0 to 6-11 and 8-0 to 9-11 years) were randomly assigned to verbal rehearsal only, model only, or model plus verbal rehearsal conditions. The task was a 6 part motor skill sequence in which proper sequencing and quality of form were assessed. A 2 × 3 × 4 (age group by model type by trial blocks) repeated measures MANOVA revealed a significant three-way interaction. Older children performed equally well under any of the model type conditions during both performance and learning. For younger children, a model plus rehearsal was superior to rehearsal only on sequence and form at performance and learning and superior to model only on sequence scores during the first two performance trial blocks. Model only and model plus rehearsal conditions were equally effective on form scores. These results suggest that age differences exist in the modeling of motor skills under conditions varying in model type, sequence and form scores, and performance and learning phases.  相似文献   

15.
Abstract

This study investigated the effects of sex and athletic status on reaction latencies and movement time. One hundred subjects, categorized into five groups of 20 subjects each—male athletes (MA), female athletes (FA), male nonathletes (MNA), female nonathletes (FNA), and control group (CG)—were tested over a period of five consecutive days. Several different types of incentives were used to ensure that subjects provided the fastest times possible. Two blocks of 25 trials were administered to each subject on each day. A 2 × 2 × 2 × 5 × 2 mixed factorial analysis of variance was used to test for between-subject differences of group (experimental/control), sex, and athletic status and for within-subject differences of days and blocks. The four dependent variables were reaction time (RT) mean, RT consistency, movement time (MT) mean, and MT consistency. Results did not support the classic finding of male superiority over females in RT/MT or athletes' superiority over nonathletes. Evidence of athletic superiority emerged, but for the first day of practice only. As subjects were allowed extended practice over a 5-day test period in which knowledge of results (KR) and other incentives were provided, differences in the experimental groups disappeared. Sex was the predominant factor in consistency, with males being less variable in RT (p = .02) performance than females. There were no sex differences in MT consistency.  相似文献   

16.
The purpose of this study was twofold: (1) to determine the gross motor coordination performance levels of junior tennis players and (2) to analyse the effects of age and gender. Participants were junior male (n = 50) and female (n = 51) tennis players aged 6–14. Körperkoordinationstest für Kinder (KTK) was used to assess the gross motor coordination of the participants. Results revealed that none of the participants performed lower than normal level in motor coordination. Besides, 40.6% of the participants performed above normal level. No gender differences were found on all subtests of KTK and also on total motor quotient. Although older players performed better on each test than their younger counterparts for the raw scores, no significant age effect was observed on motor quotient scores among different age groups.  相似文献   

17.
This study evaluated the association between the frequency of tennis play and executive function in children and adolescents. One hundred and six junior tennis players (6–15 years old) participated in this study. Executive function, including inhibitory control, working memory, and cognitive flexibility were evaluated at rest. Females showed better inhibitory control and cognitive flexibility than males. In males, more frequent tennis play was associated with higher basic processing speed and inhibitory control after controlling for age, gender, body mass index (BMI), and tennis experience. More frequent tennis play was associated with better working memory in both males and females after controlling for age, gender, BMI, and tennis experience. Furthermore, longer tennis experience was related to better cognitive flexibility in males after controlling for age, gender, BMI, and frequency of tennis play. These findings suggest that tennis play is associated with the development of three foundational aspects of executive function (i.e. inhibitory control, working memory, cognitive flexibility). Especially, frequent participation in tennis play is related to better inhibitory control and working memory, while longer experience of tennis play is associated with better cognitive flexibility. Although development of inhibitory control and cognitive flexibility is slower in males than in females, the associations between tennis play and inhibitory control and cognitive flexibility appear to be larger in males than in females.  相似文献   

18.
Purpose: The purpose of this study was to analyze tracking and stability of motor coordination in children from age 6 years to ages 9 and 13 years. Method: Data were from the Copenhagen School Child Intervention Study. Motor coordination (MC) was measured using the körperkoordinationstest für Kinder (KTK) test. The crude performance score on every item was converted into a standardized “score” based on the original German reference study, which was used to generate a total standardized motor coordination (MQ) score. The MQ scores, which represented children's level of gross MC, were classified as low (MQ score < 85), normal (MQ score = 85–115), or high (MQ score>115). Pearson correlation was used to calculate the tracking coefficients of each KTK element and MQ score, and weighted kappa was used to analyze maintenance in MC classification groups. Mixed-effects logistic regression analyses were performed to examine the odds of remaining in the low MC group over time based on body mass index (BMI), weight, and height tertiles. Results: Tracking coefficients among the MQ score and each KTK element at different ages were moderate (r>.35). Children in the highest BMI and weight tertiles had a 5.44 and 5.15 times greater chance to be in the lower MC classification group during the 7-year follow-up, respectively, in comparison with children in their lowest tertiles. Conclusion: MC tracked moderately through childhood to early adolescence. Because heavier children had a greater chance to be in the lower MC group at older ages, intervention may be useful at earlier ages for those with lower MC and disadvantageous weight status.  相似文献   

19.
Differences in motor performance according to chronological age and gender of 341 young Nigerian children (ages 3 to 5) were examined. Motor test items designed by Morris et al. (1981) were administered to the subjects. Analysis of variance was used to determine significant differences in the motor performance of the groups. In the whole sample, more age differences than sex differences in performance were noted. Except for the balancing and running performances of the girls, a fairly linear trend of improvement with age was observed in the motor performances of the groups. At each age level the boys consistently performed better than the girls in four of the six motor tests (catching, standing long jump, tennis ball throw and speed run). Generally, the 4‐ and 5‐year‐old children performed homogeneously, with a great disparity in performance noted for the 3‐year‐old children. The results of this study confirm that age and sex differences in motor performance occur at early childhood. Prospective studies should seek to control the extraneous factors which influence motor development and account for the observed differences in motor performance of pre‐school children.  相似文献   

20.
Abstract

Although vertical jumping is often incorporated into physical activity tests for both adults and children, normative data for children and adolescents are lacking in the literature. The objectives of this study were to provide normative data of jump height and predicted peak leg power for males and females aged 10.0–15.9 years. Altogether, 1845 children from 12 state primary and secondary schools in the East of England participated in the study. Each child performed two countermovement jumps, and jump height was calculated using a NewTest jump mat. The highest jump was used for analysis and in the calculation of predicted peak power. Jump height and predicted peak leg power were significantly higher for males than females from the age of 11 years. Jump height and peak power increased significantly year on year for males. For females, jump height and predicted peak leg power reached a plateau after age 12 and 13 years respectively. This study provides normative data that can be used as a tool to classify jumping performance in children aged 10–15 years.  相似文献   

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