Injury Risk Estimation Expertise Assessing the ACL Injury Risk Estimation Quiz

Background: Available methods for screening anterior cruciate ligament (ACL) injury risk are effective but limited in application as they generally rely on expensive and time-consuming biomechanical movement analysis. A potential efficient alternative to biomechanical screening is skilled movement analysis via visual inspection (ie, having experts estimate injury risk factors based on observations of athletes’ movements). Purpose: To develop a brief, valid psychometric assessment of ACL injury risk factor estimation skill: the ACL Injury Risk Estimation Quiz (ACL-IQ). Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: A total of 660 individuals participated in various stages of the study, including athletes, physicians, physical therapists, athletic trainers, exercise science researchers/students, and members of the general public in the United States. The ACL-IQ was fully computerized and made available online (www.ACL-IQ.org). Item sampling/reduction, reliability analysis, cross-validation, and convergent/discriminant validity analysis were conducted to optimize the efficiency and validity of the assessment. Results: Psychometric optimization techniques identified a short (mean time, 2 min 24 s), robust, 5-item assessment with high reliability (test-retest: r = 0.90) and consistent discriminability (average difference of exercise science professionals vs general population: Cohen d = 1.98). Exercise science professionals and general population individuals scored 74% and 53% correct, respectively. Convergent and discriminant validity was demonstrated. Scores on the ACL-IQ were most associated with ACL knowledge and various cue utilities and were least associated with domain-general spatial/decision-making ability, personality, or other demographic variables. Overall, 23% of the total sample (40% exercise science professionals; 6% general population) performed better than or equal to the ACL nomogram. Conclusion: This study presents the results of a systematic approach to assess individual differences in ACL injury risk factor estimation skill; the assessment approach is efficient (ie, it can be completed in\3 min) and psychometrically robust. The results provide evidence that some individuals have the ability to visually estimate ACL injury risk factors more accurately than other instrument-based ACL risk estimation methods (ie, ACL nomogram). The ACL-IQ provides the foundation for assessing the efficacy of observational ACL injury risk factor assessment (ie, does simple skilled visual inspection reduce ACL injuries?). It also provides a representative task environment that can be used to increase our understanding of the perceptual-cognitive mechanisms underlying observational movement analysis and to improve injury risk assessment performance

Keeping an eye on noisy movements: On different approaches to perceptual-motor skill research and training

Contemporary theorising on the complementary nature of perception and action in expert performance has led to the emergence of different emphases in studying movement coordination and gaze behaviour. On the one hand, coordination research has examined the role that variability plays in movement control, evidencing that variability facilitates individualised adaptations during both learning and performance. On the other hand, and at odds with this principle, the majority of gaze behaviour studies have tended to average data over participants and trials, proposing the importance of universal 'optimal' gaze patterns in a given task, for all performers, irrespective of stage of learning. In this article, new lines of inquiry are considered with the aim of reconciling these two distinct approaches. The role that inter- and intra-individual variability may play in gaze behaviours is considered, before suggesting directions for future research

Expertise differences in anticipatory judgements during a temporally and spatially occluded dynamic task

There is contradictory evidence surrounding the role of critical cues in the successful anticipation of penalty kick outcome. In the current study, skilled and less-skilled soccer goalkeepers were required to anticipate spatially (full body; hip region) and temporally (–160 ms, –80 ms before, foot–ball contact) occluded penalty kicks. The skilled group outperformed the less-skilled group in all conditions. Both groups performed better in the full body, compared to hip region condition. Later temporal occlusion conditions were associated with increased performance in the correct response and correct side analysis, but not for correct height. These data suggest that there is enough postural information from the hip region for skilled goalkeepers to make highly accurate predictions of penalty kick direction, however, other regions are needed in order to make predictions of height. These data demonstrate the evolution of cues over time and have implications for anticipation training

Visual Search Strategies of Soccer Players Executing a Power vs. Placement Penalty Kick

Introduction: When taking a soccer penalty kick, there are two distinct kicking techniques that can be adopted; a ‘power’ penalty or a ‘placement’ penalty. The current study investigated how the type of penalty kick being taken affected the kicker’s visual search strategy and where the ball hit the goal (end ball location). Method: Wearing a portable eye tracker, 12 university footballers executed 2 power and placement penalty kicks, indoors, both with and without the presence of a goalkeeper. Video cameras were used to determine initial ball velocity and end ball location. Results: When taking the power penalty, the football was kicked significantly harder and more centrally in the goal compared to the placement penalty. During the power penalty, players fixated on the football for longer and more often at the goalkeeper (and by implication the middle of the goal), whereas in the placement penalty, fixated longer at the goal, specifically the edges. Findings remained consistent irrespective of goalkeeper presence. Discussion/conclusion: Findings indicate differences in visual search strategy and end ball location as a function of type of penalty kick. When taking the placement penalty, players fixated and kicked the football to the edges of the goal in an attempt to direct the ball to an area that the goalkeeper would have difficulty reaching and saving. Fixating significantly longer on the football when taking the power compared to placement penalty indicates a greater importance of obtaining visual information from the football. This can be attributed to ensuring accurate foot-to-ball contact and subsequent generation of ball velocity. Aligning gaze and kicking the football centrally in the goal when executing the power compared to placement penalty may have been a strategy to reduce the risk of kicking wide of the goal altogether

The impact of visual illusions on perception, action planning, and motor performance

The present study extended recent research revealing that illusions can influence performance in golf putting (Witt, Linkenauger, & Proffitt Psychological Science, 23, 397–399, 2012), by exploring the potential mediating roles of attention and action planning. Glover and Dixon’s (Journal of Experimental Psychology. Human Perception and Performance, 27, 560–572, 2001) planning–control model suggests that both perceptual and movement-planning processes are prone to illusion-based bias. We therefore predicted that both the perception of target size and a measure of attentional control related to movement planning in golf putting (the quiet eye) would be influenced by the illusion. Moreover, as performance could not be corrected using online control (once the ball was struck), we predicted that these biases would also influence performance. We therefore proposed a three-stage process by which illusory context biases perceptual processes, which in turn bias subsequent attentional control related to movement planning, which in turn biases motor performance. Forty novice golfers completed an Ebbinghaus illusion putting task that was designed to manipulate their perceptions of target size, while quiet eye duration and performance (mean radial error) were measured. The results indicated that the illusion was effective in facilitating differences in perceived target size, with perceptually bigger holes promoting longer quiet eye durations and more accurate putting. Follow-up mediation analyses revealed that illusion-based differences in size perception partially mediated illusion-based differences in both quiet eye duration and performance. Moreover, the relationship between illusion-based differences in quiet eye duration and performance was also significant. Future research should further test this three-stage process of bias in other far-aiming tasks in which online control cannot be use

Efeito da oclusão temporal na ação de ataque sobre a tomada de decisão defensiva na modalidade de voleibol

O presente estudo analisou o efeito da oclusão temporal na cortada do voleibol sobre a tomada de decisão defensiva em atletas com diferentes níveis de experiência. Os participantes foram divididos em três grupos: adulto (GAD; n = 16), infanto/mirim (GIM; n =16) e adulto novato (GNO; n = 16). Imagens da finalização de jogadas de ataque realizadas por quatro atletas foram editadas em cinco diferentes momentos: (OT1) a 399 ms (12 quadros) antes do contato do atacante com a bola; (OT2) a 266 ms (oito quadros) antes; (OT3) a 133 ms (quatro quadros) antes; (OT4) no momento do contato atacante/bola e; (OT5) a 133 ms (quatro quadros) após o contato do atacante com a bola. Ao assistirem os vídeos editados, os participantes deveriam informar o local de aterrissagem da bola seguido da confiança com a qual emitiam suas respostas. Foi mensurada a precisão na predição da trajetória da bola (acerto/erro) e a confiança da resposta (escala Likert 1-5). Quanto à frequência de acertos, o grupo GAD (X = 63,67 ± 10,38%) apresentou maior frequência de acertos que GIM (X = 55,46 ± 10,17%) em OT2 (p = 0,001). A frequência de acertos de GAD (X = 79,29 ± 10,38%) também foi maior que a de GNO (X = 71,87 ± 10,43%) em OT3 (p = 0,012). As condições mostraram-se diferentes entre si (Bonferroni's p < 0,005), com a frequência de acertos aumentando de OT1 (X = 36,06 ± 12,44%) à OT5 (X = 98,17 ± 4,81%). Para confiança, GAD e GIM apresentaram-se mais confiantes que GNO (Bonferroni's p < 0,016) em OT1, OT2, OT3. Novamente, as condições diferiram entre si (Bonferroni's p < 0,005), com os grupos mostrando-se mais confiantes em OT5. Concluiu-se que, independente da experiência, os grupos se mostraram capazes de predizer a localização de aterrissagem da bola. Contudo, grupos com maior experiência mostraram-se superior quanto à sua capacidade antecipatória

Athletes and novices are differently capable to recognize feint and non-feint actions

Güldenpenning I, Steinke A, Koester D, Schack T. Athletes and novices are differently capable to recognize feint and non-feint actions. Experimental Brain Research. 2013;230(3):333-343.Fast motor reactions in sports often require the ability to predict the intended action of an opponent as early as possible. Therefore, the present paper investigates whether beach volleyball athletes are able to recognize different attack hits (i.e. smash vs. poke shot) at an earlier stage of the movement than novices. Beach volleyball athletes and novices took part in a response priming experiment (Experiment 1). Participants had to decide whether a presented target picture depicts a smash or a poke shot. Importantly, the preceding prime pictures were taken from different stages of the movements varying between the jump (beginning of the movements) and the hand-ball contact (end of the movements). Diverging response congruency effects was found for athletes and novices. Athletes were able to recognize at an earlier movement stage than novices which kind of attack hit was shown at the prime picture. It is suggested that athletes might implicitly read movement-related patterns in the depicted athlete's body posture (e.g. the angle of the elbow). In contrast, novices might use information which is easier to access (e.g. hand-ball relation). In a second experiment, novice participants received a visual training to test for a potential perceptual source of the priming effects. Notably, participants did not improve their ability to differentiate the volleyball techniques, indicating that a better recognition performance in athletes is based on motor and not on perceptual expertise