Junior football players' classification of runners as their teammates from 400-msec. video clips

It was hypothesized that a specialized gait recognition skill enables humans to distinguish the gait of familiar from unfamiliar individuals, and that this may have relevance in team sports. Runners seen for less than half a second can be classified as teammates or not by adult players, so it may be asked whether this skill would also be demonstrated by young team players. In the current study, junior football players (M age = 10.0 yr., SD = 0.8, N = 13) viewed 400-msec. video clips of runners sprinting past a fixed forward facing digital video camera and similarly showed teammate recognition scores significantly above chance. Given the variation among the junior players in this skill, it seems possible for researchers to assess whether improvement can be obtained with structured training for young team players, where running teammates are seen in peripheral vision during training drills.     

Experience level influences the effect of attentional focus on sprint performance

Two experiments evaluated the influence of attentional focus on 10-meter sprint time and start kinetics in a group of collegiate soccer players and highly experienced sprinters. In Experiment 1, the collegiate soccer players were asked to perform 10-meter sprints under an external focus condition, an internal focus condition and a control condition. For the 10-meter sprint time, the results showed that both the external focus and control conditions resulted in significantly faster sprint times than the internal focus condition. There were no significant differences observed between the external focus and control conditions. There were also no significant differences observed across any of the conditions for a select set of kinetic variables. In Experiment 2, the highly experienced sprinters performed the same 10-meter sprint task using the same instructional conditions as in Experiment 1. For the 10-meter sprint time and kinetic variables, there were no significant differences observed across any of the conditions. These results provide new evidence that experience level mediates the influence of attentional focus on sprint performance.     

Peripheral vision and back tuck somersaults.

Although vision appears to enhance performance of somersaulting skills, few studies have investigated the source (foveal or ambient) of useful visual cues that can potentially be used by gymnasts during a somersault. Therefore, the primary objectives were to investigate the possible role of peripheral vision in the control of orientation and landing balance in a back tuck somersault. 10 female gymnasts (age = 11.6 +/- 2.7 yr., competitive level = 8 +/- 1.2, training time in gymnastics = 5.9 +/- 1.6 yr.) performed back tuck somersaults under four visual conditions (full visual field, horizontal peripheral vision limited to 100 degrees, horizonal peripheral vision limited to 60 degrees, and no vision) while wearing electromagnetic sensors that allowed automatic digitizing. Analysis yielded no statistically significant difference on any of the kinematic variables among vision conditions. Despite limiting the gymnasts' available horizontal peripheral vision, joint angles, angular velocities, and timing remained very similar. There were no statistically significant differences in landing balance between the conditions of full vision, 100 degrees peripheral vision, and 60 peripheral vision. However, gymnasts were less stable at landing when vision was absent as compared to the three other vision conditions.     

Interval endurance capacity of talented youth soccer players

The purpose of this study, in which 113 talented youth soccer players (M = 16.0 yr., SD = 1.5), selected by their age and level of performance participated, was to investigate interval endurance capacity needed to play at the highest level of competition in the age-category 12 through 18. Multivariate analyses of covariance with factors of level of performance and age category showed that players ages 16 through 18 years outscored the players ages 12 through 15 years on the interval endurance capacity (p < .05). In both age categories, elite players outscored less skilled players (p < .05). In the age category 12-15 years, the elite players participated more in soccer training than less skilled players (p < .05), whereas less skilled players participated more in additional training than the elite players (p < .05). No differences were found for total training (p > .05). In conclusion, development of the interval endurance capacity seems crucial for a talented youth soccer player to be successful.     

Short-duration, high-intensity exercise and performance of a sports-specific skill: a preliminary study

The purpose of this study was to examine the effect of one bout and three intermittent bouts of short-duration, high-intensity running on the performance of a sports-specific psychomotor skill. Participants (N=13) were male soccer players (M age 20.5 yr., SD=2.0) who had been playing semi-professionally for M=2.1 years, SD=1.11 and trained twice a week. They undertook a soccer-passing test in three conditions: following rest, following a 100-m sprint and following 3 x 100-m sprints, with 30-sec. rest intervals between sprints. Passing accuracy showed a significant linear deterioration, while number of passes showed a significant quadratic effect. Low to moderate linear regression correlations were found between posttest heart rate and absolute and variable errors on the test. It was concluded that short-duration, high-intensity exercise has a negative effect on accuracy in a sports-specific task that requires both perceptual judgment and motor control.     

Self-Control in Professional Soccer Players

This study aimed to investigate the concept of self-control in association with engagement in daily activities of professional soccer players and its relationship with soccer performance. Findings indicated that self-control scores of male professional soccer players (N = 639), representing the first squad of every club playing in the (Norwegian) Premier and Second League, were associated with their lifestyle and practice time. A small, positive relationship between self-control and soccer performance was found. In terms of expert performance, a possible explanation of our findings is that self-control helps individuals stay on track on their pathways to excellence.     

How anterior pelvic tilt affects the lower extremity kinematics during the late swing phase in soccer players while running: A time series analysis

Anterior pelvic tilt has been proposed to predispose the hamstring in soccer players to injury at the late swing phase during a sprint, however the mechanism on how the changes in the alignment would affect the kinematics are still unclear. Thirty-four male amateur soccer players were recruited for this study. Pelvic tilt was measured using the DIERS Formetric 4D. Lower extremity angles were recorded using an 8-camera Vicon motion capture system at 200 Hz while the athlete performed a high speed run on a motorised treadmill. Late swing phase was extracted from 5 running cycle which were later analysed using statistical parametric mapping (SPM). The results show that the increase of anterior pelvic tilt angle was significantly correlated with hip (r = −0.421 to −0.462, p = 0.015) and knee flexion (r = −0.424 to −0.472, p = 0.026) values. No other correlation was found between the anterior pelvic tilt and the angles at the coronal plane. By using time series analysis it was shown that the anterior pelvic tilt measured in a standing position would affect the adjacent segments’ kinematics while running as suggested in the kinetic chain theory; which would potentially predispose the soccer athletes to hamstring injury by maintaining knee extension.     

Effects of providing advance cues during a soccer penalty kick on the kicker's rate of success

The effect of explicitly providing goalkeeper's movement advanced cue to the kicker during a real penalty kick task was assessed. 32 expert soccer players (M age= 23.2 yr.), who were divided into four groups: an experimental group, a discovery group, a placebo group, and a control group, participated. Rate of success in the task was assessed, as well as goals, decision times, and ball flight times. Providing an advance cue significantly improved the players' rate of success relative to players without the advance cue; this difference was still present after 1 and 7 days without training. The experimental group adapted better to the time range within which the response could be effective, while the discovery group showed adaptations. Explicit instructions about the advance cues available from goalkeepers' actions before the dive during practice can improve penalty kick performance.     

A hierarchical model of approach achievement motivation and effort regulation during a 90-min. soccer match

Research indicates that effort close to the lactate threshold during a soccer match is of importance to succeed, so a prospective study was conducted and a hierarchical achievement motivation approach model tested in relation to effort reglation among 55 male high level soccer players (M=23.6 yr., SD=4.3). The motive to chieve success was expected to be positively associated with the mastery goal, which would be positively associated with playing time close to the lactate threshold in the irst soccer match period, and this positively associated with the same magnitude of effort in the second period. We also examined whether the mastery goal would medite the link between the motive to achieve success and playing time close to the lactate threshold during the first period and also playing time close to the lactate threshold in the first period would mediate the link between the mastery goal and playing time at this effort level during the second period. LISREL analyses supported these predictions. Additional hierarchical polynomial multiple regression analyses indicated unexpected significant nonlinear associations between the motive to avoid failure and effort regulation. The latter is partly explained by ideas from the catastrophe theory.     

Perceptual-cognitive expertise, practice history profiles and recall performance in soccer

We examined whether high- or low-performing soccer players, classified based on established measures of perceptual-cognitive expertise, differed in regard to their practice history profiles and ability to recall elements of match performance. In Study 1, we measured perceptual-cognitive expertise in elite (n= 48) and non-elite (n= 12) youth soccer players using empirical tests of perceptual-cognitive skill. We then used a quartile split to stratify elite players into either high-performing (n= 12) or low-performing (n= 12) groups based on their test scores. A group of non-elite soccer players (n= 12) acted as controls. In Study 2, we used an established questionnaire to examine retrospectively the participation history profiles of the three groups. The high-performing group had accumulated more hours in soccer-specific play activity over the last 6 years of engagement in the sport compared to their low-performing counterparts and the non-elite controls. No differences were reported for hours accumulated in soccer-specific practice or competition between the high- and low-performing groups. In Study 3, a novel test was developed to examine episodic memory recall in soccer. Although this test successfully differentiated elite from non-elite players, no differences were evident between high- and low-performing groups, implying that episodic memory recall may not be a crucial component of perceptual-cognitive expertise in soccer.     

Eye colour and reaction time to visual stimuli in rugby league players.

Subjects with dark eye colour are thought to perform better on reactive tasks in comparison to light-eyed subjects, whereas light-eyed subjects show enhanced performance over dark-eyed subjects on self-paced activities. This study examined reaction time using unrestricted and peripheral vision and success at the self-paced activity of goal kicking in 59 elite male Rugby League players. Subjects with dark eye colour did not react significantly faster than the light-eyed subjects when tested using unrestricted vision or peripheral vision. Examination of the self-paced activity of goal kicking showed that the percentage success rate was not significantly higher in the light-eyed group than the dark-eyed group. In conclusion, there was no significant difference in reaction time to a visual stimulus or success in goal kicking between dark- and light-eyed Rugby League players.     

Perceptual-cognitive performance of youth soccer players in a 360°-environment – Differences between age groups and performance levels

IntroductionAn important requirement for soccer players is the accurate and rapid processing of dynamic and complex visual scenes. Therefore, in high-level youth soccer the players’ perceptual-cognitive skills are highly relevant from a scientific and practical point of view. The aim of the present study was to investigate differences in perceptual-cognitive performance between youth soccer players of different age groups and soccer performance levels in a dynamic 360°-environment.MethodsIn a sample of 292 elite and sub-elite youth soccer players from the age groups U12–U23, perceptual-cognitive skills were assessed using a 360°-multiple object tracking task. An 8 × 2 (age group x performance level) analysis of variance (ANOVA) was conducted to examine the effects of age group and soccer performance level on performance in the task.ResultsThe analyses revealed a significant main effect of age group. Post hoc analyses showed that youth players belonging to the older age groups (U16, U17, U19, and U23) performed significantly better in the 360°-multiple object tracking task than players of the youngest age group (U12). Yet no significant age-related differences could be found from age group U16 on. Furthermore, there was a significant effect of soccer performance level on the 360°-multiple object tracking performance in favor of the elite players. Significant differences between elite and sub-elite players within the same age group were only present in the highest age groups U19 and U23.ConclusionsThe results suggest that in a dynamic 360°-environment highly talented youth soccer players show better perceptual-cognitive performance with increasing age. Furthermore, elite youth players exhibit distinctive perceptual-cognitive abilities particularly at the highest age groups. These findings provide interesting implications for science and practice regarding the perceptual-cognitive skills of talented soccer players and their role in talent development.     

Handedness and footedness: relations to differences in sprinting speed and multiple sprints performance in prepubertal boys

Physical performance and movement skills are differentiated by brain hemispheric dominance. Relations of handedness and footedness to differences in sprint speed and multiple sprints performances were investigated in 362 prepubertal, male, novice wrestlers. Participants with two months of irregular training experience were grouped by hand and foot preferences and matched on age and anthropometry. Mean running speed was associated with the number of sprints and handedness, but not with footedness. The decrease in sprint speed was less for right-handed subjects, who also had better sprinting speed and multiple sprint performance. Symmetrical arm and leg strength development for left-handers should be emphasized.     

A multidimensional approach to skilled perception and performance in sport

Three experiments examined the relative importance of attributes determined largely by the efficiency of the visual/central nervous system versus cognitive domain‐specific skills, in the determination of expertise in soccer. In Experiment 1, expert and intermediate soccer players were assessed on various non‐specific abilities including: processing (simple reaction time, peripheral reaction time, visual correction time), optometric (static, dynamic and mesopic acuity), and perimetric parameters (horizontal and vertical peripheral range). In Experiment 2, domain‐specific variables were assessed including complex decision speed and accuracy, number of visual fixations, fixation duration, and fixation location in solving game problems. Stimuli were initially presented by slides (Experiment 2) and later by 16 mm film (Experiment 3). Eye movements were recorded and analysed. A stepwise discriminant analysis of both non‐specific abilities and soccer‐specific skills revealed an average squared canonical correlation=0.84, with the significant step variables all being domain‐specific skills. Copyright © 1999 John Wiley & Sons, Ltd.     

Excess of mixed-footedness among professional soccer players

This study concerns the distribution of footedness among professional soccer players (n=415) and nonsporting university students (n=430). Chi-squared showed that there were statistically significant differences between the proportion of mixed-footedness in the two groups (p<.0001). It appears that mixed-footedness or the ability to use both feet with an almost equal consistency is an important factor in the potential of individuals to reach high skill in soccer play. The mixed-footedness of these professional soccer players can be understood best in terms of both the nature of the game and genetic predisposition. This result is of direct interest in the context of those activities in which structural and functional biases in the lower extremities are important variables in acquisition and performance of motor skill.     

Effect of intermittent exercise on multiple-choice reaction times of soccer players

The influence of intermittent exercise on a choice-response time task was investigated. Two groups of 8 male soccer players (M age = 20.9, SD = 2.0) participated. They spent 4.4 (SD = 1.3) weekly hours on soccer training and had been playing soccer for 13 (SD = 3.3) years. Multiple-choice reaction speed and response accuracy were measured four times. Between measurements, one group performed 8-min. blocks of intermittent exercise on a bicycle ergometer and one group rested. Analysis showed that reaction speed and response accuracy were not significantly different between the two groups. Furthermore, there were significant faster reaction times and a larger number of correct reactions through Block 2 in both the exercise and control group (p < .05), probably a result of learning processes and familiarization with the task procedures. Further research towards the specific influence of mode of exercise, intensity, work-rest ratio and duration of intermittent exercise, and the sensitivity of reaction time tasks will be necessary to clarify the relationship between intermittent exercise and cognitive performance.     

Examining the reliability and predictive validity of performance assessments by soccer coaches and scouts: The influence of structured collection and mechanical combination of information

Soccer coaches and scouts typically assess in-game soccer performance to predict players’ future performance. However, there is hardly any research on the reliability and predictive validity of coaches’ and scouts’ performance assessments, or on strategies they can use to optimize their predictions. In the current study, we examined whether robust principles from psychological research on selection – namely structured information collection and mechanical combination of predictor information through a decision-rule – improve soccer coaches’ and scouts’ performance assessments. A total of n = 96 soccer coaches and scouts participated in an elaborate within-subjects experiment. Participants watched soccer players’ performance on video, rated their performance in both a structured and unstructured manner, and combined their ratings in a holistic and mechanical way. We examined the inter-rater reliability of the ratings and assessed the predictive validity by relating the ratings to players’ future market values. Contrary to our expectations, we did not find that ratings based on structured assessment paired with mechanical combination of the ratings showed higher inter-rater reliability and predictive validity. In contrast, unstructured-holistic ratings yielded the highest reliability and predictive validity, although differences were marginal. Overall, reliability was poor and predictive validities small-to-moderate, regardless of the approach used to rate players’ performance. The findings provide insights into the difficulty of predicting future performance in soccer.     

Assessing cue usage in performance contexts: A comparison between eye-movement and concurrent verbal report methods

The relationship between eye fixations and concurrent verbal reports as measures of selective attention was examined in two different performance contexts. Experienced and less experienced soccer players were presented with filmed action sequences. In Experiment 1, subjects reacted to 11-versus-11 soccer simulations; in Experiment 2, 3-versus-3 situations were presented. Each study involved two experimental conditions: (1) visual fixations were recorded using an eye-movement system and (2) subjects continuously verbalized the location of their visual attention. In 11-versus-11 situations, there were no differences in performance across the two conditions, indicating that verbalization had no effect on performance. Also, there were no differences between the two methods in identifying important information sources. In 3-versus-3 situations, concurrent verbalization resulted in reactivity. Moreover, there were differences between the two methods in identifying important display areas. Findings showed that the relationship between visual fixation and selective attention is dependent on the nature of the stimulus presented. When peripheral vision is employed to extract task-specific information, verbal reports provide a more veritable measure of selective attention; eye fixations may yield a more accurate measure when the task requires information to be extracted foveally. Findings are discussed with regard to the differences between “looking” and “seeing” as a methodological issue.     

Visual skills involved in decision making by expert referees

Previous studies have compared visual skills of expert and novice athletes; referees' performance has not been addressed. Visual skills of two groups of expert referees, successful and unsuccessful in decision making, were compared. Using video clips of soccer matches to assess decision-making success of 41 national and international referees from 31 to 42 years of age, 10 top referees were selected as the Successful group and 10 as the Unsuccessful group. Visual tests included visual memory, visual reaction time, peripheral vision, recognition speed, saccadic eye movement, and facility of accommodation. The Successful group had better visual skills than the Unsuccessful group. Such visual skills enhance soccer referees' performance and may be recommended for young referees.     

Effects of the axis of rotation and primordially solicited limb of high level athletes in a mental rotation task

A recent set of studies has investigated the selective effects of particular physical activities that require full-body rotations, such as gymnastics and wrestling (Moreau, Clerc, Mansy-Dannay, & Guerrien, 2012; Steggemann, Engbert, & Weigelt, 2011), and demonstrated that practicing these activities imparts a clear advantage in in-plane body rotation performance. Other athletes, such as handball and soccer players, whose activities do require body rotations may have more experience with in-depth rotations. The present study examined the effect of two components that are differently solicited in sport practices on the mental rotation ability: the rotation axis (in-plane, in-depth) and the predominantly used limb (arms, legs). Handball players, soccer players, and gymnasts were asked to rotate handball and soccer strike images mentally, which were presented in different in-plane and in-depth orientations. The results revealed that handball and soccer players performed the in-depth rotations faster than in-plane rotations; however, the two rotation axes did not differ in gymnasts. In addition, soccer players performed the mental rotations of handball strike images slower. Our findings suggest that the development of mental rotation tasks that involve the major components of a physical activity allows and is necessary for specifying the links between this activity and the mental rotation performance.