How can novel task constraints be used to induce acute changes in gaze behaviour?

Abstract

Quiet eye (QE) is a robust phenomenon in golf putting and expert players frequently demonstrate longer QE periods (i.e., the final fixation prior to the onset of the putting motion) relative to their less-skilled counterparts. In this experiment we used a pre-test/post-test design to determine whether we could use novel training aids and instructions to elicit acute changes in QE behaviour after a brief intervention. Three techniques were used: a marker under the ball, a hole-focus instruction, and a novel putting device – the putting box of science (PBoS). We compared gaze behaviour before and after 30 practice putts and found significant changes in QE duration in the absence of concomitant changes in putting performance. The control (?18 ms) and PBoS (+198 ms) groups did not change, the hole-focus group (?287 ms) had a decrease in QE duration, and the marker group (+366 ms) increased in QE duration. These finding are discussed relative to current QE training programs and the implications for development of evidence-based training aids with coach consultation.     

Effects of physical randomness training on virtual and laboratory golf putting performance in novices

External randomness exists in all sports but is perhaps most obvious in golf putting where robotic putters sink only 80% of 5 m putts due to unpredictable ball-green dynamics. The purpose of this study was to test whether physical randomness training can improve putting performance in novices. A virtual random-physics golf-putting game was developed based on controlled ball-roll data. Thirty-two subjects were assigned a unique randomness gain (RG) ranging from 0.1 to 2.0-times real-world randomness. Putter face kinematics were measured in 5 m laboratory putts before and after five days of virtual training. Performance was quantified using putt success rate and “miss-adjustment correlation” (MAC), the correlation between left-right miss magnitude and subsequent right-left kinematic adjustments. Results showed no RG-success correlation (r = ?0.066, p = 0.719) but mildly stronger correlations with MAC for face angle (r = ?0.168, p = 0.358) and clubhead path (r = ?0.302, p = 0.093). The strongest RG-MAC correlation was observed during virtual training (r = ?0.692, p < 0.001). These results suggest that subjects quickly adapt to physical randomness in virtual training, and also that this learning may weakly transfer to real golf putting kinematics. Adaptation to external physical randomness during virtual training may therefore help golfers adapt to external randomness in real-world environments.     

Evidence for biomechanics and motor learning research improving golf performance

The aim of this review was to determine how the findings of biomechanics and motor control/learning research may be used to improve golf performance. To be eligible, the biomechanics and motor learning studies had to use direct (ball displacement and shot accuracy) or indirect (clubhead velocity and clubface angle) golf performance outcome measures. Biomechanical studies suggested that reducing the radius path of the hands during the downswing, increasing wrist torque and/or range of motion, delaying wrist motion to late in the downswing, increasing downswing amplitude, improving sequential acceleration of body parts, improving weight transfer, and utilising X-factor stretch and physical conditioning programmes can improve clubhead velocity. Motor learning studies suggested that golf performance improved more when golfers focused on swing outcome or clubhead movement rather than specific body movements. A distributed practice approach involving multiple sessions per week of blocked, errorless practice may be best for improving putting accuracy of novice golfers, although variable practice may be better for skilled golfers. Video, verbal, or a combination of video and verbal feedback can increase mid-short iron distance in novice to mid-handicap (hcp) golfers. Coaches should not only continue to critique swing technique but also consider how the focus, structure, and types of feedback for practice may alter learning for different groups of golfers.     

Quiet eye training aids the long-term learning of throwing and catching in children: Preliminary evidence for a predictive control strategy

Abstract

Quiet eye training (QET) may be a more effective method for teaching children to catch than traditional training (TT) methods, but it is unclear if the benefits accrued persist in the long term. Thirty children were randomly allocated into a QET or TT group and, while wearing a mobile eye tracker, underwent baseline testing, training and two retention tests over a period of eight weeks, using a validated throw and catch task. During training, movement-related information was provided to both groups, while the QET group received additional instruction to increase the duration of their targeting fixation (QE1) on the wall prior to the throw, and pursuit tracking (QE2) period on the ball prior to catching. In both immediate (R1) and delayed (R2, six weeks later) retention tests, the QET group had a significantly longer QE1 duration and an earlier and longer QE2 duration, compared to the TT group, who revealed no improvements. A performance advantage was also found for the QET compared to the TT group at both R1 and R2, revealing the relatively robust nature of the visuomotor alterations. Regression analyses suggested that only the duration of QE1 predicted variance in catch success post-training, pointing to the importance of a pre-programming visuomotor strategy for successful throw and catch performance.     

Using visual guidance to retrain an experienced golfer’s gaze: A case study

Eye movements are essential for both predictive and reactive control of complex motor skills such as the golf swing. We examined the use of a visually guided learning protocol to retrain an experienced golfer’s point-of-gaze immediately prior to execution of the full golf swing; his swing, and his gaze behaviour, had become established over more than a decade of practice and competition. Performance and eye movement data were obtained, from baseline, through intervention, to retention, for a total of 159 shots struck at a target 200 yards away. Results show that, at baseline, not only was the golfer’s point-of-gaze not at the intended/predicted location, at the top-rear of the ball, but there was also high trial-to-trial variability. A bespoke visual guidance protocol improved his gaze behaviour considerably, in terms of accuracy and consistency – and this was reflected in accuracy and consistency of his shots. Implications of oculomotor interventions for the relearning of established motor skills are discussed.     

Synchronized metronome training induces changes in the kinematic properties of the golf swing

The purpose of this study was to evaluate possible effects of synchronized metronome training (SMT) on movement dynamics during golf-swing performance, as captured by kinematic analysis. A one-group, between-test design was applied on 13 male golfers (27.5 ± 4.6 years old, 12.7 ± 4.9 handicap) who completed 12 sessions of SMT over a four-week period. Pre- and post-assessments of golf swings with three different clubs (4-iron, 7-iron, and pitching wedge) were performed using a three-dimensional motion capture system. Club velocity at three different swing phases (backswing, downswing, and follow-through) was measured and cross-correlation analysis of time-series signals were made on joint couplings (wrist–elbow–shoulder) of both arms, and between joints and the club, during the full golf swing. There were significantly higher cross-correlations between joint-couplings and concomitant changes of the associated phase-shift differences, as well as reduced phase-shift variability at post-test. No significant effect of SMT was found for the club velocities. We suggest that domain-general influences of SMT on the underlying brain-based motor control strategies lead to a more coordinated movement pattern of the golf-swing performance, which may explain previous observations of significantly improved golf-shot accuracy and decreased variability after SMT.     

State anxiety and motor performance: Testing the conscious processing hypothesis

Previous research has argued that skills acquired explicitly are more likely to fail under stressful conditions than skills that have been learned implicitly.The present study addressed an alternative explanation for the robustness under stress of implicit task performance. As implicit learners acquired the skill of golf putting while generating random letters, it is possible that they became desensitized to self-generated verbalizations and thus immune to the effects of competitive anxiety. We tested this interpretation while controlling for a further rival hypothesis generated by Eysenck's Processing Efficiency Theory. Wealso examined the effect of increased state anxiety on the kinematic processes underlying performance breakdowns. For task performance, we found evidence that partially supported the conscious processing hypothesis, while the results of the kinematic analysis of the putting stroke were equivocal. Analysis of self-reported effort scores provided partial support for processing efficiency theory.     

The effect of dimple error on the horizontal launch angle and side spin of the golf ball during putting

This study aimed to examine the effect of the impact point on the golf ball on the horizontal launch angle and side spin during putting with a mechanical putting arm and human participants. Putts of 3.2 m were completed with a mechanical putting arm (four putter-ball combinations, total of 160 trials) and human participants (two putter-ball combinations, total of 337 trials). The centre of the dimple pattern (centroid) was located and the following variables were measured: distance and angle of the impact point from the centroid and surface area of the impact zone. Multiple regression analysis was conducted to identify whether impact variables had significant associations with ball roll variables, horizontal launch angle and side spin. Significant associations were identified between impact variables and horizontal launch angle with the mechanical putting arm but this was not replicated with human participants. The variability caused by “dimple error” was minimal with the mechanical putting arm and not evident with human participants. Differences between the mechanical putting arm and human participants may be due to the way impulse is imparted on the ball. Therefore it is concluded that variability of impact point on the golf ball has a minimal effect on putting performance.     

The stroke has only a minor influence on direction consistency in golf putting among elite players

In the golf instructional literature, the putting stroke is typically given higher priority than green reading and aiming. The main purpose of this study was to assess the importance of the putting stroke for direction consistency in golf putting. Kinematic stroke parameters were recorded from 71 elite golf players (mean handicap = 1.8, s = 4.2) on 1301 putts from about 4 m. Of the different factors deciding stroke direction consistency, face angle was found to be the most important (80%), followed by putter path (17%) and impact point (3%). This suggests that improvements in consistency of putter path and impact point will have very little effect on overall putting direction consistency and should not be prioritized in the training of elite players. In addition, mean stroke direction variability for an elite player (European Tour) was found to be 0.39 degrees, which is good enough to hole about 95% of all 4-m putts. In practice, however, top professionals in tournaments only hole about 17% of 4-m putts. We conclude that the putting stroke of elite golfers has a relatively minor influence on direction consistency.     

The Effect of Gradual Self-Control of Task Difficulty and Feedback on Learning Golf Putting

ABSTRACT

Purpose: This study aimed to examine the effect of gradual self-control of task difficulty and feedback on accuracy and movement pattern of the golf putting sport skill. Method: Sixty students were quasi-randomly assigned to four groups under a varying combination of the two factors of task difficulty control (self-controlled or yoked) and feedback control (self-controlled or yoked). The participants in the two groups (dual-factor gradual self-control and self-controlled task difficulty group) that granted control over task difficulty in the acquisition phase were told they could choose any of the pre-set distances from the target. All groups were given 100% feedback in the first half of the acquisition phase, but the participants in the two groups (dual-factor gradual self-control group and self-controlled feedback) that could control their feedback were told that in the second half of the acquisition phase they would be able to ask for feedback when needed. The practice schedule of each member of the dual-factor gradual self-control group was used as a basis to plan the practice of predetermined distances and feedback presentation to the corresponding participants in the yoked conditions. Results: ANOVA with repeated measures showed that the practice method involving gradual self-control of two factors had a positive impact on accuracy and movement pattern of golf putting in the retention and transfer tests compared to other methods (p_s < .05). Conclusion: The advantages of self-control practice presumably come from better adjustment of challenge points by the learner in the course of the practice.     

State anxiety and motor performance: testing the conscious processing hypothesis

Previous research has argued that skills acquired explicitly are more likely to fail under stressful conditions than skills that have been learned implicitly. The present study addressed an alternative explanation for the robustness under stress of implicit task performance. As implicit learners acquired the skill of golf putting while generating random letters, it is possible that they became desensitized to self-generated verbalizations and thus immune to the effects of competitive anxiety. We tested this interpretation while controlling for a further rival hypothesis generated by Eysenck's Processing Efficiency Theory. We also examined the effect of increased state anxiety on the kinematic processes underlying performance breakdowns. For task performance, we found evidence that partially supported the conscious processing hypothesis, while the results of the kinematic analysis of the putting stroke were equivocal. Analysis of self-reported effort scores provided partial support for processing efficiency theory.     

Three-dimensional trunk kinematics in golf: between-club differences and relationships to clubhead speed

The aims of this study were (i) to determine whether significant three-dimensional (3D) trunk kinematic differences existed between a driver and a five-iron during a golf swing; and (ii) to determine the anthropometric, physiological, and trunk kinematic variables associated with clubhead speed. Trunk range of motion and golf swing kinematic data were collected from 15 low-handicap male golfers (handicap = 2.5 ± 1.9). Data were collected using a 10-camera motion capture system operating at 250 Hz. Data on clubhead speed and ball velocity were collected using a real-time launch monitor. Paired t-tests revealed nine significant (p ≤ 0.0019) between-club differences for golf swing kinematics, namely trunk and lower trunk flexion/extension and lower trunk axial rotation. Multiple regression analyses explained 33.7–66.7% of the variance in clubhead speed for the driver and five-iron, respectively, with both trunk and lower trunk variables showing associations with clubhead speed. Future studies should consider the role of the upper limbs and modifiable features of the golf club in developing clubhead speed for the driver in particular.     

Directional aiming bias in golf putting

Johnston, Benton, and Nishida (2003, Last but not least - Golfers may have to overcome a persistent visuospatial illusion. Perception, 32(9), 1151–1154) reported that when standing sideways to hit a golf ball, it becomes very difficult to see the veridical line of putt to the target and it creates a bias to misread the direction to the right of target. The purpose of the study was to determine if this perceptual aiming bias also impacts putting. A group of expert (N = 24) and novice (N = 24) players performed a perception task of aligning a line on the golf ball towards the target hole and an action task of putting a ball to the target hole located 1 m and 4 m away. Novice players showed large perceptual aiming bias and small action aiming bias of putting. Yet, expert players showed neither bias in perceptual aiming nor in putting. This replicates earlier work (van Lier, van der Kamp, & Savelsbergh, 2011 Perception action in golf putting: Skill differences reflect calibration. Journal of Sport & Exercise Psychology, 33(3), 349–369) and was explained by the two-visual-pathway hypothesis. Despite the results showing some favorable support for the two-visual-pathway hypothesis, possible limitations are discussed.     

On generalized rolling of golf balls considering an offset center of mass and rolling resistance: a study of putting

This paper seeks to address the implications on putting a golf ball with an off-center mass by analyzing the effect of unbalanced mass of ball on its impact and subsequent rolling. We present the general formulation of a rigid golf ball rolling with slip that is able to transition to rolling friction on an arbitrary surface. Particular attention is given to the effects of the offset center of mass on the golf ball’s path. An experimental setup based on a USGA Stimpmeter is used to calibrate the position of contact point as the ball rolls on the green. The trajectories of the ball due to the mass imbalance were studied by numerically solving the equations of motion during putting. Theoretical predictions show that a mass imbalance has little effect on the launch conditions of the ball. However, on a level green a mass offset center of 0.2 % of the ball’s radius can impact the path of the ball with the consequences of missing the hole in a 5.8 m putt. Changing golf ball trajectories with mass offset center has implications on the development of balls and putting.     

Methodological considerations for the 3D measurement of the X-factor and lower trunk movement in golf

It is believed that increasing the X-factor (movement of the shoulders relative to the hips) during the golf swing can increase ball velocity at impact. Increasing the X-factor may also increase the risk of low back pain. The aim of this study was to provide recommendations for the three-dimensional (3D) measurement of the X-factor and lower trunk movement during the golf swing. This three-part validation study involved; (1) developing and validating models and related algorithms (2) comparing 3D data obtained during static positions representative of the golf swing to visual estimates and (3) comparing 3D data obtained during dynamic golf swings to images gained from high-speed video. Of particular interest were issues related to sequence dependency. After models and algorithms were validated, results from parts two and three of the study supported the conclusion that a lateral bending/flexion-extension/axial rotation (ZYX) order of rotation was deemed to be the most suitable Cardanic sequence to use in the assessment of the X-factor and lower trunk movement in the golf swing. The findings of this study have relevance for further research examining the X-factor its relationship to club head speed and lower trunk movement and low back pain in golf.     

国外高尔夫推杆心理研究进展

推杆是高尔夫项目运动技能的重要组成部分,在比赛中对比赛成绩有显著影响,也是高尔夫心理学研究的热点主题。研究对国外高尔夫推杆心理的研究进行总结,分析了学习（练习）方式、认知加工策略、专项感知能力、注意等因素对高尔夫推杆的影响,以及运动动机、竞赛焦虑、注意、生理状态、静眼和"Yips"与竞赛中推杆表现的关系;提出了注意力训练、表象训练、节奏反馈策略和辅助策略训练等高尔夫推杆心理训练的方法。在此基础上总结了当前研究的局限并指出今后研究的方向。     

Methodological considerations for the 3D measurement of the X-factor and lower trunk movement in golf

It is believed that increasing the X-factor (movement of the shoulders relative to the hips) during the golf swing can increase ball velocity at impact. Increasing the X-factor may also increase the risk of low back pain. The aim of this study was to provide recommendations for the three-dimensional (3D) measurement of the X-factor and lower trunk movement during the golf swing. This three-part validation study involved; (1) developing and validating models and related algorithms (2) comparing 3D data obtained during static positions representative of the golf swing to visual estimates and (3) comparing 3D data obtained during dynamic golf swings to images gained from high-speed video. Of particular interest were issues related to sequence dependency. After models and algorithms were validated, results from parts two and three of the study supported the conclusion that a lateral bending/flexion-extension/axial rotation (ZYX) order of rotation was deemed to be the most suitable Cardanic sequence to use in the assessment of the X-factor and lower trunk movement in the golf swing. The findings of this study have relevance for further research examining the X-factor its relationship to club head speed and lower trunk movement and low back pain in golf.     

Putts that get missed on the right: Investigating lateralized attentional biases and the nature of putting errors in golf

Abstract

Although the effects of lateral biases in visual attention (“pseudoneglect”) have been examined in real-world settings, this phenomenon has yet to be considered within the realm of sporting performance. In the present study, we investigated the effects of pseudoneglect on putting errors in golf. Novice golfers (n = 30) performed 90 putting trials followed by a series of pseudoneglect tasks: requiring participants to bisect lines manually and with a biomechanical bisection tool. All pseudoneglect measures were performed with both the left and right hands. Results demonstrated a leftward bias for all the pseudoneglect tasks, and a rightward bias for putting error. Moreover, the results revealed that individuals who bisected lines to the left on the Bisection Tool (the typical class of pseudoneglect error for humans) with the left hand (the hand that typically produces the greatest pseudoneglect bias) displayed significantly smaller rightward putting errors. Moreover, these individuals also holed more putts. No other pseudoneglect tasks were shown to impact on putting performance. Our findings suggest that lateralized attentional biases have a significant effect on sport performance; they appear to influence a wide range of precision-based sports (e.g. shooting, archery). Findings are also discussed in terms of the processes that are likely to be involved in this effect.     

Perception and action in golf putting: skill differences reflect calibration

We assessed how golfers cope with the commonly observed systematic overshoot errors in the perception of the direction between the ball and the hole. Experiments 1 and 2, in which participants were required to rotate a pointer such that it pointed to the center of the hole, showed that errors in perceived direction (in degrees of deviation from the perfect aiming line) are destroyed when the head is constrained to move within a plane perpendicular to the green. Experiment 3 compared the errors in perceived direction and putting errors of novice and skilled players. Unlike the perceived direction, putting accuracy (in degrees of deviation from the perfect aiming line) was not affected by head position. Novices did show a rightward putting error, while skilled players did not. We argue that the skill-related differences in putting accuracy reflect a process of recalibration. Implications for aiming in golf are discussed.     

Taxonomy of golf putting: Do different golf putting techniques exist?

Abstract

This study is a preliminary investigation into the use of cluster analysis to determine if different putting techniques existed in a group of club level golfers.

Putting at a hole 4?m away, the performances of 34 experienced golfers (age 55.3?±?17.8 years and handicap 15.3?±?6.9, range 3–27) were analysed using putter head kinematic and centre of pressure data. Two distinct putting techniques were identified (named as Arm putting and Body putting), this being the first time different putting techniques have been reported in the research literature. These techniques were defined by parameters related solely to movement of the centre of pressure along the line of the putt. Some players (17 of 34) moved between techniques when performing their putting trials. Neither technique produced more accurate putt results (P?=?0.783).

Putting technique was further analysed after grouping players according to handicap (similar skill level) or accuracy (similar putting performance). The lack of significant findings when players were re-analysed according to handicap or accuracy highlights the importance of the correct methodological approach to detecting technique differences.