Identification of interindividual and intraindividual movement patterns in handball players of varying expertise levels

The authors examined the movement patterns of 5 left-handed handball players (ranging from beginner to national level) who threw a handball to different sections of a goal as if a goalkeeper were present. The authors used time-continuous, 3-dimensional kinematic data to assess interindividual movement patterns and considered participants' intraindividual differences relative to different targets. Cluster analysis yielded the highest assignment rates for level of expertise; a mean of 92% of trials was correctly assessed. The authors observed an interaction with expertise for the intraindividual movement patterns. Variability in the novice throwers was increased, whereas (a) advanced throwers experienced a period of stability, and (b) the expert thrower's variability was increased. The results indicate that random variability characterizes novice motor performance, whereas active functional variability may exemplify expert motor performance.     

Identification of Interindividual and Intraindividual Movement Patterns in Handball Players of Varying Expertise Levels

The authors examined the movement patterns of 5 left-handed handball players (ranging from beginner to national level) who threw a handball to different sections of a goal as if a goalkeeper were present. The authors used time-continuous, 3-dimensional kinematic data to assess interindividual movement patterns and considered participants' intraindividual differences relative to different targets. Cluster analysis yielded the highest assignment rates for level of expertise; a mean of 92% of trials was correctly assessed. The authors observed an interaction with expertise for the intraindividual movement patterns. Variability in the novice throwers was increased, whereas (a) advanced throwers experienced a period of stability, and (b) the expert thrower's variability was increased. The results indicate that random variability characterizes novice motor performance, whereas active functional variability may exemplify expert motor performance.     

Movement variability and skill level of various throwing techniques

In team-handball, skilled athletes are able to adapt to different game situations that may lead to differences in movement variability. Whether movement variability affects the performance of a team-handball throw and is affected by different skill levels or throwing techniques has not yet been demonstrated. Consequently, the aims of the study were to determine differences in performance and movement variability for several throwing techniques in different phases of the throwing movement, and of different skill levels. Twenty-four team-handball players of different skill levels (n=8) performed 30 throws using various throwing techniques. Upper body kinematics was measured via an 8 camera Vicon motion capture system and movement variability was calculated. Results indicated an increase in movement variability in the distal joint movements during the acceleration phase. In addition, there was a decrease in movement variability in highly skilled and skilled players in the standing throw with run-up, which indicated an increase in the ball release speed, which was highest when using this throwing technique. We assert that team-handball players had the ability to compensate an increase in movement variability in the acceleration phase to throw accurately, and skilled players were able to control the movement, although movement variability decreased in the standing throw with run-up.     

The coupling between gaze behavior and opponent kinematics during anticipation of badminton shots

PurposeWe examined links between the kinematics of an opponent’s actions and the visual search behaviors of badminton players responding to those actions.MethodA kinematic analysis of international standard badminton players (n = 4) was undertaken as they completed a range of serves. Video of these players serving was used to create a life-size temporal occlusion test to measure anticipation responses. Expert (n = 8) and novice (n = 8) badminton players anticipated serve location while wearing an eye movement registration system.ResultsDuring the execution phase of the opponent’s movement, the kinematic analysis showed between-shot differences in distance traveled and peak acceleration at the shoulder, elbow, wrist and racket. Experts were more accurate at responding to the serves compared to novice players. Expert players fixated on the kinematic locations that were most discriminating between serve types more frequently and for a longer duration compared to novice players. Moreover, players were generally more accurate at responding to serves when they fixated vision upon the discriminating arm and racket kinematics.ConclusionsFindings extend previous literature by providing empirical evidence that expert athletes’ visual search behaviors and anticipatory responses are inextricably linked to the opponent action being observed.     

Expert anticipation from deceptive action

Expertise in sports enhances the ability to anticipate forthcoming events from the observation of a player’s actions. In the present study, we investigated whether this ability is applicable to deceptive action. In three experiments, performance at anticipating the direction change of a running opponent was examined with experienced rugby players and novice counterparts. These experiments were conducted with reaction-time and temporal-occlusion tasks, in combination with eye movement recordings and the presentation of filmed actions and their point-light representations. The main finding was that the experienced players were superior to the novices in their anticipation of deceptive actions, although their performance was still impaired by the deception, in comparison with their anticipation of nondeceptive actions. We also found that the experienced players anticipated nondeceptive actions less accurately than the novices, suggesting that the players’ expectations of deceptive actions worked negatively on their judgments of nondeceptive actions. The results obtained with the point-light representations closely resembled those obtained with the filmed sequences, indicating that anticipation was based on the kinematics of the running action. These results are discussed in the context of recent developments in research on expertise and deception in sports.     

Skill level constrains the coordination of posture and upper-limb movement in a pistol-aiming task

The purpose of the experiment was to investigate whether skill level differentially organizes the coordination of the postural system and upper limb kinematics in a pistol-aiming task. Participants aimed an air-pistol at a target center in 30 s trials as accurately as possible while standing on a force platform with shooting arm joint kinematics recorded. The novice group had greater motion of the pistol end point, arm joints and the center of pressure than the skilled group. Principal components analysis (PCA) showed that the skilled group required 2 components as opposed to the 3 components of the novice group to accommodate the variance. Coherence analysis in the 0–1 Hz bandwidth revealed that the coupling between posture and upper-limb movement was stronger in the skilled than the novice group. The findings are consistent with the view that skill acquisition reduces the kinematic variables into a lower dimensional functional unit that in pistol-aiming is defined over the collective posture and upper-limb system.     

The influence of monetary reward and punishment on psychological, physiological, behavioral and performance aspects of a golf putting task

The primary purpose of the present study was to examine kinematic characteristics and force control during a golf-putting task under a pressure condition. The secondary purpose was to provide an exploratory investigation of the relationship between changes in behavior (kinematics and force control) and performance on the one hand, and psychological (attention and affect) and physiological (arousal level) changes on the other hand. Twenty male novices performed 150 acquisition trials, followed by 10 test trials during a pressure condition induced by performance-contingent distracters: a cash reward or punishment. A three-dimensional motion analysis revealed that, during the pressure test, angular displacements of rotational movements at the horizontal plane and movement time of the arms and club during the backswing and downswing phases all decreased, while acceleration of the elbows during the downswing phase increased. Mean performance indices in all participants’ were unchanged in spite of the kinematic changes under the pressure condition. Multiple regression analyses indicated that the decrement in performance, as well as increased variability of movement time and speed, were more likely to increase when participants shifted their attention to movements. Furthermore, changes in heart rate and negative affect were related to both the increase in movement acceleration and a decrease in grip force. These findings suggest that performance and behavioral changes during golf-putting under pressure can be associated with attentional changes, along with the influences of physiological-emotional responses.     

Anticipation skill and susceptibility to deceptive movement

The ability to detect deceptive movement was examined in skilled and novice rugby players. Participants (14 per group) attempted to predict direction change from video of expert and recreational rugby players changing direction with and without deceptive movement. Confidence associated with judgments was recorded on each trial to seek evidence regarding use of inferential (heuristic-based) and direct-perceptual (invariant-based) judgments. Novices were found to be susceptible to deceptive movement whereas skilled participants were not; however, both skilled and novice participants were more confident on trials containing deceptive movement. The data suggest that the skill-level difference in sensitivity to advance visual information extends to deceptive information. The implications of this finding, and the importance of considering the underlying process of anticipation skill, are discussed.     

Examining the Time Course of Attention During Golf Putts of Two Different Lengths in Experienced Golfers

A dual-task paradigm was used to investigate the time course of attention during putting relative to task difficulty (6 ft vs. 12 ft). Putting performance and reaction time (RT) were measured while 20 experienced golfers responded verbally to an auditory tone presented at 3 probe positions (PP) during the putt: backswing initiation (PP1), backswing peak (PP2), and before impact (PP3). There were 2 significant main effects for putting performance: task difficulty (better performance on the short putt) and probe position (worse performance at PP1 vs. PP3 and Catch Trials). During the short putt, there were no significant differences in RT as a function of PP, indicating that attentional demand remained constant throughout the stroke. RT of the long putt was significantly longer than the short putt, indicating that the long putt required greater attention. Skill level was examined as a potential moderating factor but did not significantly moderate results.     

Effects of different types of analogy instruction on the performance and inter-joint coordination of novice darts learners

ObjectivesAnalogy instruction has an advantage on motor skill learning. The effect of analogy instructional type on kinematics, particularly on inter-joint coordination, is an extremely understudied area of research. Against this background, this paper experimentally controlled the quality and quantity of the to-be-learned information included in instruction and applied principal component analysis (PCA) to time-series data of joint angles to examine whether different instruction methods could change inter-joint coordination structure.Methods and designForty-five novice participants, fifteen each for three independent groups, performed dart-throwing training with either explicit, rule-based biomechanical metaphor (RBM), or information-integrated biomechanical metaphor (IIM) instructions. Performance and kinematics were evaluated in pre-test, retention test, and transfer test that can increase psychological pressure. The dependent variables were performance outcome, joint variability, and measurements derived from PCA.ResultsAnalyses revealed a significant test effect for the performance outcome, joint variability, and PCA measurements. No significant group effect or group–test interaction was found for the performance outcome and joint variability. Significant test effect and test–group interaction were found for the wrist PC1 loading. The IIM group means significantly increased in the retention and transfer tests. The explicit and RBM group means showed no significant effects of the test. These results suggest that IIM learners significantly changed the PCA structure in the retention test and maintained it in the transfer test, whereas explicit and RBM learners did not.ConclusionsThe findings provide the first insight into the effects of information-integrated biomechanical metaphors on the acquisition of inter-joint coordination structures for novice learners.     

An especial skill: Support for a learned parameters hypothesis

We tested the ‘learned parameters’ hypothesis as an explanation of the ‘especial skill effect’. Outcome attainment and movement kinematics were recorded for 10 expert and 10 novice players performing basketball free-throw shots at five distances (11-19 ft) with a regular and heavy weight basketball. As predicted, experts performed better than expected relative to the regression equation at the 15 ft, free-throw line with the regular basketball, supporting the ‘especial skill effect’. This effect was not present for the experts when shooting with the heavy ball. Novices did not show an advantage at the free-throw line when performing with either ball. Although the outcome attainment scores support the ‘learned parameters’ hypotheses, kinematic analysis failed to identify differences in the movement pattern for the especial skill, suggesting that these skills (i.e., shooting at different distances) are not governed by separate motor programs.     

The distance effect and level of expertise: Is the optimal external focus different for low-skilled and high-skilled performers?

Focusing attention on a movement effect that is farther away from the body (distal external focus) has been shown to result in more effective motor performance or learning than focusing on an effect that is in greater proximity to the body (proximal focus). The present study examined whether the distance of the external focus impacts the performance of relatively inexperienced and experienced performers differently. Low-skilled and high-skilled volleyball players passed a volleyball continuously to a target. In the proximal focus condition they were asked to concentrate on the “platform,” whereas in the distal focus condition they were instructed to concentrate on the target. The high-skilled group's accuracy scores were higher in the distal relative to proximal focus condition. However, low-skilled players' accuracy scores was greater in the proximal relative to distal focus condition. We argue that the optimal distance of the external focus depends on the level of expertise when the skill requires a specific movement technique. An external focus on that technique seems to be more advantageous for low-skilled performers. In contrast, when the movement pattern has become more automatic (high-skilled performers), a focus on the overall movement effect is more beneficial.     

Investigating the effects of movement speed on the lumbopelvic coordination during trunk flexion

Movement speed during trunk flexion has long been reported to affect task performance and biomechanical responses. The current study investigated how movement speed changed lumbopelvic coordination, especially lumbopelvic continuous relative phase and phase variability during trunk flexion. Eighteen subjects executed a paced trunk flexion routine over time periods of 3, 7, 11 and 15 seconds. The results demonstrated that compared with the 3-s condition, lumbopelvic continuous relative phase was 98.8% greater in the 15-s condition, indicating a more anti-phase coordination pattern. This pattern is suggested to mitigate the increased spinal loading associated with the longer duration of muscle exertion. Additionally, phase variability was 18.8% greater in the 15-s trials than the 3-s trials, such an unstable coordination pattern is likely caused by the more active neuromuscular control. Findings of this study provide important information about the effects of movement speed on lumbopelvic coordination during trunk flexion.     

Variability in practice: facilitation in retention and transfer through schema formation or context effects?

The main purpose of the study was to examine whether the effects of variability in practice within a class of movements, that is, enhanced retention and transfer performance relative to constant practice, are due to the formation of motor schemata (Schmidt, 1975) or to contextual interference effects, as suggested by Lee, Magill, and Weeks (1985). Forty-eight subjects were tested on a sequential timing task. One group of subjects (Schema) received variable practice within one movement class, practicing the same phasing pattern with different absolute durations. Practice conditions of another group (Context) involved the same absolute movement durations, as well as a different phasing pattern for each task version. Thus, contextual interference was about the same for both groups but only one group experienced different movement variations of the same class. On a retention test performed on a task version that had been practiced by both groups before as well as on a transfer test with the same phasing pattern but a longer absolute duration, the Schema group performed more effectively than the Context group, thus supporting schema theory. On a transfer task with new phasing requirements, however, the Context group demonstrated performance superior to that of the Schema group. In this case, the Context practice condition seemed to be more transfer-appropriate.     

Response selection and execution skills of professionals and novices during singles tennis competition.

This study extended research on sport expertise concerning the development of cognitive and motor skills in singles tennis (McPherson, 1999). 12 adult male professional and novice tennis players were videotaped during singles competition. Opponents for matches were randomly selected within each group of participants. Two tennis experts utilized an observational scale to judge players' performance generated during competition for serves and shots following the serve, e.g.. return of serves, lobs. Each player was scored on three performance components: quality of movement to or control of the ball for serves or shots attempted (control skills), appropriateness of serve or shot selections in the context of game situations (response selection skills), and quality of serves or shots produced (response execution skills). Relative frequency scores for the highest category of each performance component were derived according to the number of opportunities to respond. Serve performance indicated both groups were able to control their serves: however, professionals made more tactical selections and forceful executions. Shot performance indicated professionals made more successful movement to and control of shots, tactical shot selections, and forcing shot executions than novices. Overall, players' tactical response selections were greater than their forceful response executions. Thus, assessing players' decisions during competition may provide vital information concerning tactical skill development. Further, professional players exhibited higher and more consistent tactical behavior than elite collegiate players examined in 1999 by McPherson. Findings were attributed to tactical knowledge and motor skill development resulting from competition and practice experiences.     

The influence of proximal motor strategies on pianists' upper-limb movement variability

Repetitive movements are considered a risk factor for developing practice-related musculoskeletal disorders. Intra-participant kinematic variability might help musicians reduce the risk of injury during repetitive tasks. No research has studied the effects of proximal motion (i.e., trunk and shoulder movement) on upper-limb movement variability in pianists. The first objective was to determine the effect of proximal movement strategies and performance tempo on both intra-participant joint angle variability of upper-limb joints and endpoint variability. The second objective was to compare joint angle variability between pianist's upper-limb joints. As secondary objectives, we assessed the relationship between intra-participant joint angle variability and task range of motion (ROM) and documented inter-participant joint angle variability. The upper body kinematics of 9 expert pianists were recorded using an optoelectronic system. Participants continuously performed two right-hand chords (lateral leap motions) while changing movements based on trunk motion (with and without) and shoulder motion (counter-clockwise, back-and-forth, and clockwise) at two tempi (slow and fast). Trunk and shoulder movement strategies collectively influenced variability at the shoulder, elbow and, to a lesser extent, the wrist. Slow tempi led to greater variability at wrist and elbow flexion/extension compared to fast tempi. Endpoint variability was influenced only along the anteroposterior axis. When the trunk was static, the shoulder had the lowest joint angle variability. When trunk motion was used, elbow and shoulder variability increased, and became comparable to wrist variability. ROM was correlated with intra-participant joint angle variability, suggesting that increased task ROM might result in increased movement variability during practice. Inter-participant variability was approximately six times greater than intra-participant variability. Pianists should consider incorporating trunk motion and a variety of shoulder movements as performance strategies while performing leap motions at the piano, as they might reduce exposure to risks of injury.     

The use of anticipatory visual cues by highly skilled tennis players

The authors examined 13 skilled and 12 novice tennis performers' ability to use visual information of an opponent's movement pattern to anticipate and respond. In Experiment 1, skilled and novice players anticipated the type of stroke and the direction in which the ball was hit in a highly coupled perception-action environment. Both groups of players correctly anticipated at greater than chance levels. Skilled players were significantly more accurate than novices with live and video displays but not with point-light displays. In Experiment 2, the reaction latencies of 10 expert performers were significantly faster when they returned balls hit by a live opponent than when they returned balls projected from a cloaked ball machine. The findings indicate that experts are able to use movement-pattern information to determine shot selection and to use that information to significantly reduce their response delay times. The findings are discussed in terms of perception-action coupling in time-stress activities.     

Understanding individual differences in lifting mechanics: Do some people adopt motor control strategies that minimize biomechanical exposure

The movement strategy an individual uses to complete a lift can influence the resultant biomechanical exposure on their low back. We hypothesize that some lifters may choose a motor control strategy to minimize exposure to the low back, where others may not. Lower magnitudes of exposure to the low back coupled with less variability in lift-to-lift exposure and in features of movement strategy related to biomechanical exposure would support that such lifters consider minimizing exposure in their motor control strategy. We tested this hypothesis by investigating if differences in variability of low back exposure measures, as well as features of movement strategy related to resultant low back exposures differed across lifters. Twenty-eight healthy adults participated in the study where ten repetitions of a lifting task with the load scaled to 75% of participant's one-repetition maximum were completed. In all trials, whole-body kinematics and ground reaction forces were collected. Lifters were grouped as low, moderate or high relative exposure based on low back flexion angles and normalized L4/L5 extensor moments when lifting. Principal component analysis was used to identify independent movement strategy features, and statistical testing determined which features differed between high and low exposure lifts. Variability in low back exposures and movement features associated with relative biomechanical exposure were compared across lifter classifications. Significantly less variability was observed in low back exposures among the low exposure lifter group. Additionally, a trend towards lower variability in movement features associated with relative biomechanical exposure was also observed in low exposure lifters. These findings provide initial support for the hypothesis that some lifters likely define a motor control strategy that considers minimizing biomechanical exposure in addition to completing the lift demands. Future work should explore how state and trait-based factors influence an individual to consider biomechanical exposure within their motor control strategy in lifting.     

Motor learning methods that induce high practice variability reduce kinematic and kinetic risk factors of non-contact ACL injury

The prevention of non-contact anterior cruciate ligament (ACL) injuries often involves movement training, but the effectiveness of different motor learning methods has not been fully investigated. The purpose of this study was therefore to examine the effects of linear pedagogy (LP), nonlinear pedagogy (NLP) and differential learning (DL) motor learning methods on changing kinetic and kinematic factors during expected sidestep cutting related to non-contact ACL injuries. These methods primarily differ in the amount and type of movement variability they induce during practice. Sixty-six beginner male soccer players (27.5 ± 2.7 years, 180.6 ± 4.9 cm, 78.2 ± 4.6 kg) were randomly allocated to a group that trained for 12 weeks with either a LP, NLP or DL type of motor learning methods. All participants completed a biomechanical evaluation of side-step cutting before and after the training period. Analysis of covariance was used to compare post-testing outcomes among the groups while accounting for group differences in baseline performance. Changes in all kinematic and kinetic variables in NLP and DL groups were significantly higher compared to the LP group. Most comparisons were also different between NLP and DL group with the exception of vertical ground reaction force, the knee extension/flexion, knee valgus, and ankle dorsiflexion moments. Our findings indicate that beginner male soccer players may benefit from training programs incorporating NLP or DL versus LP to lower biomechanical factors associated with non-contact ACL injury, most likely because of the associated increased execution variability during training. We discuss that practitioners should consider using the NLP or DL methods, and particular the NLP, during which variability is induced to guide search, when implementing training programs to prevent ACL injuries in soccer.     

Changes in the variability of movement trajectories with practice

We studied variability in movement phase plane trajectories (velocity-position relation) during movement. Human subjects performed 10 degrees and 30 degrees elbow flexion and extension movements in a visual step tracking paradigm. The area of ellipses with radii equal to one standard deviation in position and velocity was taken as a measure of trajectory variability. Trajectory variability was determined at 10-ms intervals throughout movements. Trajectory variability in both the acceleration and deceleration phases of movement decreased with practice. The average trajectory variability during deceleration was greater than that during acceleration even after extended practice (1000 trials). During practice, subjects usually increased movement speed while maintaining end-position accuracy. Trajectory variability was also related to movement speed when equal amounts of practice were given. Short duration (fast) movements had greater trajectory variability than long duration movements. Thus there is a tradeoff between movement speed and trajectory variability similar to the classical speed-accuracy tradeoff. Trajectory variability increased rapidly during the acceleratory phase of movement. The rate of increase was positively related to both movement amplitude and speed. Thus, the forces producing limb acceleration were variable and this variability was more marked in faster and larger movements. In contrast, trajectory variability increased more slowly or actually decreased during the deceleratory phase of movements. Forces involved in limb deceleration thus appeared to compensate to a greater or lesser degree for the variability in accelerative forces. The experiments indicate that the entire trajectory of simple limb movements is controlled by the central nervous system. Variations in accelerative forces may be compensated for by associated variations in decelerative forces. The linkage between accelerative and decelerative forces is progressively refined with practice resulting in decreased variability of the movement trajectory.