Function Of Skill Level Research Articles

Skill level and the free moment during a pistol aiming task

ABSTRACT The present study investigated the transversal rotation of body and its relation to the horizontal movement for expert shooters and novices in a pistol aiming task. Participants stood on a force plate with an air pistol and aimed it to the centre of a target, positioned 1.4 m above the floor and 10 m away from the force plate, for 30 s as accurately as possible. The results revealed that the novice group showed greater transversal body variability represented by the free moment (FM) than the expert group. Correlation analysis showed that there is tight coupling between the FM and centre of pressure both in the anterior–posterior and medio-lateral directions for the expert group while only strong coupling of that in the anterior–posterior direction for the novice group. The findings suggest that FM is a critical factor to accurately aim the pistol on the target and there is a different postural strategy, in terms of the body motion in the transversal and horizontal space, as a function of skill level to realise success in the pistol aiming task.

Limit cycle dynamics of the gymnastics longswing

The purpose of the study was to examine the macroscopic dynamics of the longswing through a limit cycle analysis of the motion of the center of mass (CM) as a function of skill level. One elite international, five gymnasts able to perform release and regrasp skills, five gymnasts unable to perform release and regrasp skills, and five novice gymnasts each performed four consecutive longswings on a high bar. Kinematic data were collected to facilitate the calculation of the center of mass position of the performer during swinging. Poincare plots were used to explore the limit cycle dynamics of the center of mass movement. The attractor dynamic was very close to a one-dimensional limit cycle for the elite (D = 1.18) but higher for the release and regrasp group (D = 1.35 ± 0.06) and non-release and regrasp group (D = 1.37 ± 0.07). The novice dynamic was characterized by a two-dimensional limit cycle (D = 2.49 ± 0.28) that also had more variability and lower determinism. In the frequency domain, Inharmonicity was lower and the Q factor higher as a function of increased skill level. The findings show that the dynamical degrees of freedom of the CM in the skilled performance were reduced compared to those of novices and represented a more efficient and predictive, rather than exploratory, technique.

Skill level changes the coordination and variability of standing posture and movement in a pistol-aiming task

ABSTRACTThe study investigated the coordination and variability of posture and pistol motion for skilled pistol shooters and novices in a pistol-aiming task. The participants stood on a force platform and held a pistol with the preferred arm to aim for accuracy to a target on 30 s trials. The results revealed that the amount of the centre of pressure (COP) and pistol motion was lower for the expert than novice group. The time–varying structure of COP as indexed by multiscale entropy (MSE) and detrended fluctuation analysis (DFA) was also lower for the expert than the novice group. The relative phase between the COP in the anterior–posterior (AP) and pistol in the AP and between the COP in the medial–lateral (ML) and pistol in AP was close to inphase for the both groups. However, for the novice group the coordination patterns of posture and pistol motion were more variable with the pistol motion leading the posture motion while it was lagging in the skilled group. The findings show different qualitative and quantitative dynamics in pistol-aiming as a function of skill level with postural control foundational to supporting the reduced dispersion and complexity of the skilled arm-pistol motion.

사격 조준 과제 시 숙련성에 따른 압력중심의 복잡성과 양 발의 체중 부하 비교

사격 조준 과제 시 숙련성에 따른 압력중심의 복잡성과 양 발의 체중 부하 비교

Coordination and control of posture and ball release in basketball free-throw shooting

The objective of this study was to investigate the coordination of a whole-body task (basketball free-throw) in which success in performance outcome can be achieved through a manifold of combinations of postural and movement trajectory configurations. Participants were healthy men (19–24years) with a range of skill levels that were tested for the accuracy of 50 basketball free-throws with both their dominant and non-dominant hand. The trial-to-trial variance in release parameters as well as postural stability of the shooter and synchronization of postural movement and ball release were strong predictors of performance, with non-elite shooters having a higher mean and variability of center-of-mass (COM) speed at the time of ball release. The synchronization between the time of peak COM and the time of ball release increased as a function of skill level and hand dominance, with the better performers releasing the ball more closely to the time of COM peak height. These findings reveal how, in addition to successfully controlling the trial-to-trial variability along the solution manifold of release parameters, the relative importance of the coordination of postural control and ball release properties on shooting success changes as a function of skill level.

Incorporating Multiskilling and Learning in the Optimization of Crew Composition

AbstractThe presence of multiskilled workers in a crew can increase the crew’s productivity through reducing inefficiencies and supervision requirements, while also providing on-the-job learning opportunities for single-skilled workers. The effect of the presence of multiskilled workers on the learning rate of workers, which is also a function of skill level and experience, and thus on the crew’s productivity, is especially significant in repetitive construction projects. This paper presents a mathematical model for identifying the optimal combination of single-skilled and multiskilled workers with different levels of experience in the crew to minimize the duration of construction projects by accounting for the overlapping effects of multiskilling, skill level, and learning on the crew’s productivity. The model is applied to an illustrative case project to demonstrate the practicality of the model. The optimum crew compositions for different activities involved in the case project are identified using a s...

Coordination as a function of skill level in the gymnastics longswing

The purpose of this study was to investigate the nature of inter-joint coordination at different levels of skilled performance to: (1) distinguish learners who were successful versus unsuccessful in terms of their task performance; (2) investigate the pathways of change during the learning of a new coordination pattern and (3) examine how the learner’s coordination patterns relate to those of experts in the longswing gymnastics skill. Continuous relative phase of hip and shoulder joint motions was examined for longswings performed by two groups of novices, successful (n = 4) and unsuccessful (n = 4) over five practice sessions, and two expert gymnasts. Principal component analysis showed that during longswing positions where least continuous relative phase variability occurred for expert gymnasts, high variability distinguished the successful from the unsuccessful novice group. Continuous relative phase profiles of successful novices became more out-of-phase over practice and less similar to the closely in-phase coupling of the expert gymnasts. Collectively, the findings support the proposition that at the level in inter-joint coordination a technique emerges that facilitates successful performance but is not more like an expert’s movement coordination. This finding questions the appropriateness of inferring development towards a “gold champion” movement coordination.

Attentional focus effects on sprint start performance as a function of skill level

Several researchers have demonstrated that an external focus of attention (about movement’s effects) during movement execution allowed better performances and learning of various motor tasks than an internal focus of attention (about movement itself). However, attentional focus effects have not been studied in tasks requiring explosive actions preceded by fast reaction time to a signal, such as a sprint start. We hypothesised that the beneficial effect of external focus of attention would be observed in the different stages of the sprint start (i.e. reaction time, block clearance and running) for both expert and novice sprinters. Novice and expert sprinters performed sprint starts followed by a 10 m sprint under three conditions: external focus instructions; internal focus instructions; and neutral instructions. The reaction time and the running time were significantly shorter in the external focus condition than in the internal focus condition, for both expert and novice participants. These results confirm the beneficial effect of an external focus of attention on the speed of movement execution. Moreover, they revealed that attentional focus influences movement preparation. Several hypotheses are proposed to account for these results, with reference to the processes that could be responsible for the observed effects.

Performance Accomplishment Information as Predictors of Self-Efficacy as a Function of Skill Level in Amateur Golf

The predictive capabilities of different types of performance accomplishment information (PAI) towards self-efficacy for amateur golfers were compared as a function of skill level. Male golfers (N = 197; skilled n = 84, lesser skilled n = 113) recorded self-efficacy levels before and after competitive golf performance. Multiple regression analyses revealed that handicap was the most significant predictor of PAI towards pre-round self-efficacy for skilled golfers while practice satisfaction was the most significant predictor for lesser skilled. Handicap achievement was a significant predictor of post-round self-efficacy for both skilled and lesser skilled golfers. The findings imply athletes of varying skill level utilize different information when developing efficacy beliefs. Further study of the relationship between PAI and self-efficacy is therefore warranted in the sports domain.

Perceiving the affordance of string tension for power strokes in badminton: Expertise allows effective use of all string tensions

Affordances mean opportunities for action. These affordances are important for sports performance and relevant to the abilities developed by skilled athletes. In racquet sports such as badminton, different players prefer widely different string tension because it is believed to provide opportunities for effective strokes. The current study examined whether badminton players can perceive the affordance of string tension for power strokes and whether the perception of affordance itself changed as a function of skill level. The results showed that string tension constrained the striking performance of both novice and recreational players, but not of expert players. When perceptual capability was assessed, perceptual mode did not affect perception of the optimal string tension. Skilled players successfully perceived the affordance of string tension, but only experts were concerned about saving energy. Our findings demonstrated that perception of the affordance of string tension in badminton was determined by action abilities. Furthermore, experts could adjust the action to maintain a superior level of performance based on the perception of affordance.

Mental representation and learning: The influence of practice on the development of mental representation structure in complex action

ObjectivesRecent research has elicited distinct differences in mental representations between athletes of different skill levels. Such differences suggest that the structure of mental representations changes as a function of skill level. However, research examining how such mental representation structures develop over the course of learning is lacking. In the present study, we examine the effects of practice on the development of one's mental representation of a complex action during early skill acquisition. DesignFor this purpose, we created a controllable learning situation, using a repeated-measures design with a control group. More specifically, novice golfers were randomly assigned to either a practice group (n = 12) or a control group (n = 12). Both groups were tested before and after an acquisition phase of three days as well as after a three day retention interval. MethodsMental representation structures of the putt were recorded, employing the structural dimensional analysis of mental representation (SDA-M), which provides psychometric data on the structure and grouping of action concepts in long-term memory. In addition, outcome performance of the practice group was measured, using two-dimensional error scores of the putt. ResultsFindings revealed a significant improvement in task performance, as well as functional changes in the structure of the practice group's mental representation. In contrast, no functional adaptations were evident in the mental representation of the control group. ConclusionOur findings suggest that motor skill acquisition is associated with functional adaptations of action-related knowledge in long-term memory.

Competitive anxiety intensity and interpretation: A two-study investigation into their relationship with performance

Two experimental studies are reported investigating the relationship between competitive anxiety intensity and interpretation and performance within the sports of rugby union and basketball. Study 1 employed video recall procedures and the Immediate Anxiety Measurement Scale (IAMS) to assist an elite and non-elite rugby union performer recall their anxiety symptoms prior to lineout throw-ins at different levels of situation criticality. Examination of the relationship between anxiety intensity, interpretation, and performance as a function of skill level and situation criticality revealed that anxiety interpretation was a stronger predictor of performance than anxiety intensity. In addition, anxiety intensity increased, interpretations became more debilitative, and performance decreased as the situation became more critical, and anxiety intensity was lower and interpreted as more facilitative toward upcoming performance by the elite rugby union player, which coincided with better lineout performance. Study 2 measured the free-throw performance of competitive basketball players during simulated basketball matches, with anxiety responses assessed in relation to these free-throws at half time and full time. Anxiety, measured through the IAMS, was interpreted as more facilitative prior to successful free-throws with players suggesting that these interpretations were due to high levels of self-confidence that was associated with an increase in focus. Implications of the findings of both of these studies for future research and practice are provided.

Bi-stability of movement coordination as a function of skill level and task difficulty.

This study investigated whether the level of practice interacts with the initial conditions (here manipulated as preparatory movements) and task difficulty (ball angular velocity and friction) in determining the stability of movement coordination for a roller ball motor task. Practice level and task difficulty were manipulated as two control parameters that theoretically were hypothesized to change the threshold for the transition between task success and failure. The findings showed bi-stability and hysteresis in the coordination mode as a manifestation of dependence on the initial conditions. The transition from failure to success in the roller ball task as a function of practice time can be modeled as a saddle-node bifurcation corresponding to a first order phase transition. It is proposed that task difficulty acts as a control parameter that is a dual to skill level and that also effectively compensates for practice time.

Goal-Setting Effects in Elite and Nonelite Boxers

Using a goal-setting model (Burton, Naylor, & Holliday, 2001), the purpose of this study was to examine the effects of a goal-setting intervention upon performance as a function of skill level. A multiple-baseline across-individuals single subject design was employed with 3 elite and 3 nonelite male boxers aged between 15–17 years (M = 16; SD = 1). Self-generated performance behaviors, competition outcome, competitive anxiety intensity and direction, and self-confidence were measured across a competitive season (10-fight period). Retention was also examined following treatment withdrawal (2-fight period). During and after the goal program was completed, the elite participants displayed consistent improvements in targeted behaviors, more facilitative interpretations of anxiety symptoms, and greater self-confidence, whereas the nonelite revealed inconsistent patterns. Postintervention, five out of the six boxers showed improvement in the percentage of fights won. The results highlight the diverse effects of goal-setting for different populations, with social validation data suggesting potential mechanism via the goal-setting model employed and changes to attentional focus.

Sources and cognitive appraisals of acute stress as predictors of coping style among male and female Chinese athletes

The purposes of this study were to determine the extent to which sources of stressful events and cognitive appraisal of those events predict coping style and to determine differences in coping style between 138 (ns = 74 females and 64 males) Chinese college athletes at the elite level and 253 (ns = 60 females and 193 males) non‐elite athletes who had competed on their high school sports team, and currently engage in recreational (intramural) sports as college students. Two fivepoint Likert‐type inventories were developed for this study, the Sources of Acute Stress in Sport Inventory (SASSI) and the Coping Style in Sport Inventory (CSSI). The Stress Appraisal Measure (SAM; Peacock & Wong, 1990), a validated measure used extensively in the non‐sport literature, identified the athletes’ cognitive appraisals. Results of a discriminant analysis indicated that three stress sources, verbal‐abuse‐by‐others, coach‐dissatisfaction, and environmental‐sources, and two cognitive appraisals, control‐by‐self and control‐by‐others, were significant predictors for athletes’ coping styles. It was concluded that coping style is a function of the type of stressor and cognitive appraisal and that an athlete's coping style differs as a function of skill level and gender

The cognitive structure of movements in classical dance

Aims This study was designed to elicit differences in the mental representations of two basic movements from classical ballet, the Pirouette en dehors and the Pas assemblé, stored in long-term memory of dancers of different skill-levels. Method The movements were demonstrated and explained verbally to professional ballet dancers, amateur dancers, and non-dancers. Subsequently, participants were assigned to a hierarchical sorting (splitting) task in which Basic Action Concepts (BACs) of the movements had to be sorted according to their functional relevance in movement execution. The task was presented as verbal labels on a computer screen. The responses were subjected to the application of a new analytical method, called SDA-M, which includes a hierarchical cluster analysis. The method enabled eliciting cognitive structures of the movements in the participants' long-term memory, and thus enabled comparing these cognitive structures in subjects of different skill-level. Results Participants of different skill-level showed movement-specific differences in their mental representation structures in long-term memory. A similar structure was noted in advanced amateurs and professionals for the Pirouette en dehors, which referred to the functional phases of the movement, and less functional representations were noted in beginners and novices. For the Pas assemblé, the experts' representation structure was different from that of amateurs and novices, pointing toward differences in movement execution. It is concluded that movement representations of this kind in long-term memory might provide the basis for motor control in skilled ballet movements in the form of suitably organized perceptual-cognitive reference structures. Implications The results point toward a unique mental representation as a function of skill-level and movement nature. Individual and group results obtained with the applied method can be implemented to support (mental) training methods in classical dance practice.

Coordination of lower limb interceptive actions as a function of skill level

Coordination of lower limb interceptive actions as a function of skill level

배드민턴선수들의 MBTI를 이용한 성격유형별 특성

The purpose of this study was to the personality type and preference by using MBTI method. The subjects for this study totalled 278 badminton players of high school, college and profession. This study compares differences of the personality type and preferences by sex, school career and function of skill level. It helps instructors to coach the players well. The results of this study were as follows: 1. Male players show ISTJ, ISTP type tendency. Female players show ESTJ, ISTJ type tendency. There was significantly difference by sex. 2. Most high school players show ESTP, ISTP type tendency. Most College badminton players and professional players shows ISTJ, ISTP type tendency. But there was no significantly difference by school career. 3. Most skilled players show ISTJ, ISTP type tendency. Most unskilled players show ISTP, ISTJ type tendency. But there was no significantly difference by function of skill level. 4. Female players show higher tendency at I, S, P type. Male players show higher tendency at T type. But there was no significantly difference in preferences by sex.

The effects of imagery perspective as a function of skill level on alpha activity

A strategy being used by athletes to enhance their performance is imagery. In previous research studying imagery, Lang's (1977, 1979) Information-Processing Theory states two types of propositions: stimulus propositions (SP) and response propositions (RP). The beneficial use of imagery scripts emphasizing these propositions may depend on the skill level of the performer. The purpose of this study was to investigate differences in lower (8–10 Hz) and upper (11–13 Hz) alpha activities during imagery emphasizing SP and imagery emphasizing RP as related to the skill level of the subjects. Twenty-two right-handed male subjects were assigned to either an ‘expert’ ( n=11) or a ‘novice’ ( n=11) group. Lower and upper alpha activities from six active sites were recorded during imagery of a golf-putting task. After subsequent fast Fourier transform (FFT) analysis of results, mean lower and upper alpha power values were entered into separate repeated measures mixed model designs. Results revealed significant differences in skill level at the occipital sites in the lower alpha band. Moreover, a significant interaction between imagery perspective and skill level was found in the lower alpha band at the occipital site and in the upper alpha band at the parietal site. Significant differences were found in imagery perspective at the parietal, temporal, and occipital sites in the lower alpha band. In addition, a significant interaction effect, imagery perspective by hemisphere, was found in the upper alpha band at the parietal site. Conclusions are discussed based on the results and future research is suggested.

Assessment of the adiabatic transformability hypothesis in a ball-bouncing task. mbrodel@freewwweb.com.

The adiabatic transformability hypothesis for non-conservative, non-rate-limited biological systems put forward by Kugler and Turvey [Kugler PN, Turvey MT (1987) Information, natural law, and the self-assembly of rhythmic movements, Erlbaum, Hillsdale, NJ] is evaluated in a ball-bouncing task as a function of skill level. We hypothesized that, when a basketball player increases or decreases the frequency of his limb motion in a vertical ball-bouncing task, the transformation should be characterized as adiabatic. Confirmation of this hypothesis would lend support to the body of knowledge that suggests that physical-biological laws guide the behavior of people engaged in motor tasks, including their acquisition of skill. We videotaped and analyzed four participants - two intermediates and two experts - bouncing a ball from various heights, and measured the energy and kinematic relations of the ball and the participants' body segments. The task presents a challenge to certain predictions of the adiabatic hypothesis in evaluating changes in movement velocity (v) or frequency (f), and energy as adiabatic transformations. Among these are the constant relation between kinetic energy (Ek) per cycle and v, constancy of energy dissipated per cycle (Et) over changes in v and Ek, the ratio of Ek to Et per cycle (the "Q" values), and the relation of amplitude to v. From our observations, which are examined in regard to the insights of Kugler and Turvey about the relation of Ehrenfest's adiabatic theorem to biological systems, we confirm the basic adiabatic character of the task in analyzing both the ball alone and the relations of various body segments. In the segmental frame of reference, we found evidence of differences in energy-kinematic relations in the Q values between skill levels.