Vision and Visual History in Elite/Near-Elite-Level Cricketers and Rugby-League Players

Influence of trajectory and contrast on dynamic visual acuity in elite team sports players

Dynamic visual acuity (DVA) is considered an essential component for studying the visual function, especially in challenging environments like team sports. Beyond frequent comparative studies, much information is still lacking about the mechanisms underlying DVA and possible differences in stimulus presentation. It is crucial to understand the performance of DVA under different conditions of contrast and trajectories to achieve more specific data and better ecological validity of measurements. Fifty-five top professional male Spanish athletes, including 23 soccer, 14 basketball, and 18 water polo players were selected. Static visual acuity (SVA) was evaluated at 5 m. DVA was determined at 2 m under combined conditions of velocity (52°/s), three trajectories (horizontal, diagonal 45° and 135°) and two contrasts (99.7% and 13%). Significant differences in most DVA conditions measurements show that the best scores correspond to horizontal, over diagonal trajectories, and high contrast. The correlation between SVA and DVA showed a different relationship depending on the contrast conditions. Professional soccer, basketball, and water polo players have similar characteristics with reference to all the DVA evaluated conditions.

Self-efficacy assessment hinders improvement on a deliberate cricket bowling practice task

Introduction

Previous research indicates that external focused attention is linked to superior performance on motor tasks. This study examined how attention directed toward one's self-efficacy affected performance in a cricket bowling task.

Methods

In the pre-test phase, participants attempted to bowl in a designated "good length" zone across 12 trials. Following this, participants were randomly assigned to either an experimental group, where they rated their own general and task-specific self-efficacy, or a control group, where they rated someone else's ability. They each then bowled 12 more trials. Their performance was measured based on the number of trials that were bowled within the standard "good length" zone.

Results

Paired t-tests showed that while the performance of the control group improved significantly from pre-test to post-test, t = 2.613, p = 0.008; the experimental group did not show a significant improvement, t = 1.156, p = 0.131.

Discussion

Results indicate that asking people to rate their self-efficacy level may reduce their improvement on a deliberate practice task. Implications for sport performance and researchers are discussed.

Studies of Vision in Cricket-A Narrative Review

Vision is thought to play a substantial role in hitting and fielding in cricket. An understanding of which visual skills contribute during cricket play could inform future clinical training trials. This paper reviews what has been reported thus far regarding the relationship of visual skills to cricket performance and reviews the results of clinical trials in which the impact of visual skills training on cricket performance has been addressed. Fundamental or low-level visual skills, with the exception of color vision and perhaps near stereopsis and dynamic visual acuity, are similar between cricket players and the general population. Simple reaction time has been found to be shorter in cricket players in some but not all studies. While there is mixed or no evidence that the aforementioned visual skills are superior in cricket players compared to non-players, comparisons of eye and head movements and gaze tracking have revealed consistent differences between elite cricket batters and sub-elite batters. Future training studies could examine whether teaching sub-elite batters to emulate the gaze tracking patterns of elite batters is beneficial for batting. Lastly, clinical trials in which visual skills of cricket players have been trained have in many cases resulted in positive effects on visual skills, or judgments required in cricket, or cricket play. However, clinical trials with larger and more diverse groups of participants and correlations to on-field metrics and on-field performance (i.e., domain-specific assessments) are necessary before conclusions can be drawn regarding the efficacy of vision training.

Differences in visio-spatial intelligence between non-athletes and netball players

There is conflicting evidence regarding whether athletes have better visio-spatial skills than non-athletes. This gap may result from athletes' superiority in only some visio-spatial abilities (VSS), rather than all areas of vision. The aim of this study was to determine whether there is a significant difference in the visio-spatial intelligence between female netball players (n = 40) and non-athletes (n = 40) when comparing six visual skills (accommodation facility, saccadic eye movement, speed of recognition, peripheral awareness, hand-eye coordination, and visual memory). Following an optometric evaluation, the participants were assessed in six distinct established tests, including the hart near far rock, saccadic eye movement, evasion, accumulator, ball wall toss tests, and flash memory, to evaluate the VSS components of non-athletes and premier league netball players. For five of the six tests, there was a statistically significant (p ≤ 0.05) difference between netball players and non-athletes. Conversely, there is no concrete evidence that netball players have better visual memory than non-athletes (p = 0.277). When compared to non-athletes, netball players have significantly improved accommodation facility (p < .001), saccadic eye movements (p < .001), speed of recognition (p < .001), peripheral awareness (p < .001), and hand-eye coordination (p < .001), but not visual memory (p = 0.277). The findings that netball players perform better on a certain VSS have broad ramifications for theories of sport vision, the optimal way to choose tests, and the creation of VSS testing batteries for specific sports.

Effect of a Prolonged Maximal Bout of Exercise on Visual Performance

Background: Despite it being purported that acute, prolonged maximal periods of exercise may impair visual performance, little/no research on this topic is forthcoming. In fact, research has demonstrated that sub-maximal and maximal acute exercise may actually improve cognitive and sensory tasks and thus possibly improve visual performance. Objectives: This study aimed to ascertain the influence of an acute, prolonged maximal bout of exercise on visual performance. Methods: A quantitative study was undertaken with 60 untrained males being divided into a control group (CON; n = 30) or treatment group (TRE; n = 30). Both groups completed a baseline vision test battery consisting of accommodation facility, saccadic eye movement, speed of recognition, peripheral awareness, visual memory, and hand-eye coordination using the following tests; Hart Near Far Rock, saccadic eye movement, evasion, accumulator, flash memory and Ball Wall Toss tests. Two weeks later, participants returned for follow-up testing using the same vision test battery, with the TRE participants first engaging in a standardized incremental maximal treadmill protocol immediately prior to their vision testing. Results: Following the incremental maximal treadmill protocol, statistical analyses indicated that statistically significant (P ≤ 0.05) differences existed for accommodation facility, saccadic eye movements, speed of recognition, hand-eye coordination, peripheral awareness, and visual memory between pre-test and after the aerobic treatment (P = 0.00 for all measures). Conclusions: This study indicates that an acute, prolonged maximal bout of running improves visual performance. As such, an appropriate prolonged maximal warm-up may be required as opposed to a standardized and general warm-up when preparing an athlete for visual skills training or for participation in an athletic event that requires optimal visual performance.

Topical Review: Visual Performance Assessments for Sport

SIGNIFICANCE

Eye care professionals seek to provide effective vision care for a variety of patient needs, including performance in sports and recreational pursuits. This review provides an analysis of common visual performance assessments, including summaries of recent clinical research from a diverse array of professional literature.Vision is recognized as an important element of sports performance. Elite athletes frequently demonstrate exceptional abilities to see and respond effectively in sports competition. Which visual factors are important and how to most effectively assess visual performance are the sources of much debate. This topical review presents an evidence-based review of the common visual performance factors assessed in athletes, beginning with guidance for conducting a visual task analysis for the variety of sports that athlete patients may compete in. An information processing model is used to provide a framework for understanding the contributions of the many visual performance factors used during sports.

Differences in visio-spatial expertise between 1st division rugby players and non-athletes

The present study aimed to compare the visual expertise of non-athletes (n = 40; 19–35 years old; age: 22.13 ± 2.37 years) to amateur, non-professional South-African Rugby Union (SARU) first-division club rugby players (n = 40; 19–35 years old; age: 23.88 ± 4.36 years; training age mean: 9.0 ± 1.5 years). Research suggests that athletes have enhanced visio-spatial expertise in comparison to non-athletes. However, conflicting research suggests that this is not always the case as non-athletes possess similar visio-spatial expertise in certain visual skills. Participants underwent an optometric assessment after which the following 6 visio-spatial intelligence (VSI) components were measured; accommodation facility, saccadic eye movement, speed of recognition, peripheral awareness, visual memory and hand-eye coordination using the following tests; hart near far rock, saccadic eye movement, evasion, accumulator, flash memory and ball wall toss tests. Results indicated that first-division rugby players performed significantly better (p ≤ 0.05) in five of the six tests performed, except for visual memory (p = 0.893). While this study substantiates the notion that athletes, in this case first-division rugby players, performs significantly better in most VSI components, this is not the case for all, as with visual memory in this study. To more accurately distinguish between athletes and non-athletes, research should move away from tests that focus on basic visual function and develop sport specific testing methods that can be used by a variety of sports.

Extraordinary Dynamic Near Vision in Champion Shotgun Shooters: PDI Check Evaluation of Stereo and Color without Floor Effect

BACKGROUND

Conventional near and stereo tests have a "floor effect;" inability to discriminate normal from super-normal. Shotgun champions require unique performance in binocularity and rapid color discrimination.

PATIENTS AND METHODS

Twenty-nine champion clay-target shooters, 14 normal Army and 12 color-normal subjects were tested with conventional near vision tests and on PDI-Check, a series of dynamic, near vision tests on the autostereoscopic Nintendo console.

RESULTS

Conventional tested shotgunners had all perfect Ishihara and 75% best 40 sec Stereo fly while Army had 92%perfect Ishihara and 69% best stereo fly. On PDI-Check, experienced shotgunners with median stereo of 17 (IQR 12-41) arc sec were better than Army volunteers 59 (IQR 30 to 487) arc seconds (Mann-Whitney U=62, p=0.04). Median PDI-Check for shotgun compared to Army was 88% compared to 84% for blue cone, 90% compared to 84% for green and 77% compared to 72% (red, Mann-Whitney p=0.05). Adding dark cherry filter shooting glasses improved the red and green color detection (p<0.01). This study lacked power to detect eye dominance using PDI Check color or stereo.

CONCLUSION

Many champion shotgun shooters had outstanding dynamic near stereo and better-than-average color vision which could be optimized with dark filter spectacles for red and green hues. PDI Check not only helps identify abnormal binocularity and color vision, but it can clarify supranormal vision as well.

Qualities or skills discriminating under 19 rugby players by playing standards: a comparative analysis of elite, sub-elite and non-rugby players using the SCRuM test battery

Objective

Although schoolboy rugby is growing in popularity and played at different competitive levels in Zimbabwe, the influence of playing standard on qualities or skills of older male adolescent rugby players is unknown. Utilising a cross-sectional design, this study determined anthropometric, physiological characteristics and rugby-specific game skills defining elite under 19 (U19) schoolboy rugby players. Following development and subsequent assessment of test–retest reliability of School Clinical Rugby Measure (SCRuM) test battery, this study compared performance outcomes of elite rugby players (n = 41), sub-elite rugby players (n = 46) and non-rugby athletes (n = 26) to identify qualities or skills discriminating (i) elite from sub-elite and non-rugby players, and concomitantly (ii) sub-elite from non-rugby players.

Results

40 m speed test (p < 0.001, ES = 1.78) and 2 kg Medicine Ball Chest Throw test (p < 0.001, ES = 1.69) significantly discriminated elite U19 from sub-elite and non-rugby players. These tests further differentiated sub-elite from non-rugby athletes. Additionally, 1RM back squat (p = 0.009, ES = 0.57), 1RM bench press (p = 0.005, ES = 0.61), repeated high-intensity exercise test (p < 0.001, ES = 0.88) and passing ability test (p < 0.001, ES = 0.99) discriminated elite from sub-elite counterparts. These findings highlight important attributes linked to elite U19 schoolboy rugby in Zimbabwe. However, no significant differences were observed for sum of seven skinfold (p = 0.28), tackling (p = 0.08) and catching ability (p = 0.05).