The relationship between the golf swing plane and ball impact characteristics using trajectory ellipse fitting     

Andrew Morrison  Denise McGrath  Eric S. Wallace 《Journal of sports sciences》2018,36(3):303-310

The trajectory of the clubhead close to ball impact during the golf swing has previously been shown to be planar. However, the relationship between the plane orientation and the orientation characteristics of the clubhead at ball impact has yet to be defined. Fifty-two male golfers (27 high skilled, 25 intermediate skilled) hit 40 drives each in an indoor biomechanics laboratory. This study successfully fitted the trajectory of the clubhead near impact to an ellipse for each swing for players of different skill levels to help better explain this relationship. Additionally, the eccentricities of the ellipses were investigated for links to skill level. The trajectory of the clubhead was found to fit to an ellipse with RMSE of 1.2 mm. The eccentricity of the ellipse was found to be greater in the high-skilled golfers. The club path and angle of attack generated from the ellipse fitted clubhead trajectory were found to have a normalised bias-corrected RMSE of 2% and 3%, respectively. A set of “rule of thumb” values for the relationship between the club path, angle of attack and delivery plane angle was generated for use by coaches.  相似文献   

Applications of Augmented Reality in Informal Science Learning Sites: a Review     

Eric E. Goff  Kelly Lynn Mulvey  Matthew J. Irvin  Adam Hartstone-Rose 《Journal of Science Education and Technology》2018,27(5):433-447

The importance of increasing interest in the STEM disciplines has been noted in a number of recent national reports. While many previous studies have focused on such efforts inside of the formal classroom, comparatively few have looked closely at informal learning environments. We investigate the innovative use of technology in informal learning by reviewing research on the incorporation of augmented reality (AR) at exhibit-based informal science education (ISE) settings in the literature. We report on the common STEM-focused topics that are covered by current AR applications for ISE learning, as well as the different devices used to support these applications. Additionally, we report on the prevalence of positive learning outcomes and engagement factors commonly associated with the use AR applications in informal environments. This review aims to foster continued development and implementation of AR technology in exhibit-based ISE settings by informing the community of recent findings and promoting additional rigorous research for the future.  相似文献   

Effects of a Mindfulness-Based Intervention on the Perception of Basic Psychological Need Satisfaction among Special Education Students     

Catherine Malboeuf-Hurtubise  Mireille Joussemet  Geneviève Taylor  Eric Lacourse 《International Journal of Disability, Development & Education》2018,65(1):33-44

Mindfulness-Based Interventions (MBIs) have been increasingly implemented in schools to foster better emotional regulation skills for students with special education needs such as learning disabilities (LDs). This pilot study aimed to evaluate the impact of a MBI on the need satisfaction of elementary students with severe LDs. A prospective quasi-experimental design involving one group and two time points was employed. A sample of 14 elementary school students from a severe LDs special education class participated in this project. Repeated-measures ANOVAs were conducted and revealed a significant reduction in need satisfaction, with a large effect size (η² = .35). Contrary to our hypothesis, the MBI appeared to be negatively related to need satisfaction among participants. These results indicate that MBIs could be linked with better self-evaluation skills in students with severe LDs, which, in turn, may change (or increase the accuracy of) the perception that children have of their own need satisfaction.  相似文献   

Editorial     

Eric Thain  Roger Bartlett 《Journal of sports sciences》2013,31(8):613-614

  相似文献   

基于三阶段DEA的中国区域二氧化碳排放绩效评价研究   总被引：5，自引：2，他引：3  

华坚  任俊  徐敏  Eric Fong 《资源科学》2013,35(7):1447-1454

要在促进社会经济发展的同时减少二氧化碳排放量,关键在于提高二氧化碳排放绩效.客观正确地评估中国各省份经济发展过程中的二氧化碳排放绩效具有重要现实意义.文章从效率的角度,界定二氧化碳排放绩效的概念,将二氧化碳排放作为非期望产出纳入全要素研究框架,探索性地利用三阶段DEA方法和线性数据转换函数法来评价中国省际区域的二氧化碳排放绩效,剔除了环境变量和随机误差对结果的影响,为真实测度二氧化碳排放绩效提供了可行的方法.结果表明,传统DEA测度的二氧化碳排放平均技术效率和纯技术效率被低估,而平均规模效率被高估;中国区域间二氧化碳排放绩效发展显著不平衡,呈现出“东＞西＞中”的格局,与传统的经济格局存在一定出入.  相似文献   

Optimising technical skills and physical loading in small-sided basketball games     

Markus J. Klusemann  David B. Pyne  Carl Foster  Eric J. Drinkwater 《Journal of sports sciences》2013,31(14):1463-1471

Abstract

Differences in physiological, physical, and technical demands of small-sided basketball games related to the number of players, court size, and work-to-rest ratios are not well characterised. A controlled trial was conducted to compare the influence of number of players (2v2/4v4), court size (half/full court) and work-to-rest ratios (4x2.5 min/2x5 min) on the demands of small-sided games. Sixteen elite male and female junior players (aged 15–19 years) completed eight variations of a small-sided game in randomised order over a six-week period. Heart rate responses and rating of perceived exertion (RPE) were measured to assess the physiological load. Movement patterns and technical elements were assessed by video analysis. There were ～60% more technical elements in 2v2 and ～20% more in half court games. Heart rate (86 ± 4% & 83 ± 5% of maximum; mean ± SD) and RPE (8 ± 2 & 6 ± 2; scale 1–10) were moderately higher in 2v2 than 4v4 small-sided games, respectively. The 2v2 format elicited substantially more sprints (36 ±12%; mean ±90% confidence limits) and high intensity shuffling (75 ±17%) than 4v4. Full court games required substantially more jogging (9 ±6%) compared to half court games. Fewer players in small-sided basketball games substantially increases the technical, physiological and physical demands.  相似文献   

The effects of eccentric phase duration on concentric outcomes in the back squat and bench press in well-trained males     

Joseph P. Carzoli  Colby A. Sousa  Daniel J. Belcher  Eric R. Helms  Andy V. Khamoui  Michael Whitehurst 《Journal of sports sciences》2013,31(23):2676-2684

ABSTRACT

The velocity and magnitude in which the eccentric phase of an exercise is completed directly affects performance during the concentric phase. Therefore, the purpose of this research was to investigate the effects of eccentric phase duration on concentric outcomes at 60% and 80% of one-repetition maximum (1RM) in the squat and bench press. Sixteen college-aged, resistance-trained males completed 1RM testing, established normative eccentric durations, and performed fast (0.75 times normative) and slow (2.0 times normative) metronome-controlled eccentric duration repetitions. Outcome measures assessed during the concentric phase were: average concentric velocity (ACV), peak concentric velocity (PCV), rating of perceived exertion (RPE), range of motion (ROM), and barbell path. Eccentric duration was significantly and inversely correlated with ACV at 60% (r = ?0.408, p = 0.004) and 80% (r = ?0.477, p = 0.001) of 1RM squat. At 60% of 1RM squat, both fast and slow eccentric conditions produced greater (p < 0.001) PCV than normative duration with fast also producing greater PCV than slow (p = 0.044). Eccentric duration had no impact on RPE, ROM, or barbell path. Our results report for the first time that resistance-trained males performing a deliberately faster eccentric phase may enhance their own squat and bench press performance.  相似文献   

The Relation of Mild Traumatic Brain Injury to Chronic Lapses of Attention     

Matthew B. Pontifex  Steven P. Broglio  Eric S. Drollette  Mark R. Scudder  Chris R. Johnson  Phillip M. Oapos;Connor 《Research quarterly for exercise and sport》2013,84(4):553-559

We assessed the extent to which failures in sustained attention were associated with chronic mild traumatic brain injury (mTBI) deficits in cognitive control among college-age young adults with and without a history of sport-related concussion. Participants completed the ImPACT computer-based assessment and a modified flanker task. Results indicated that a history of mTBI, relative to healthy controls, was associated with inferior overall flanker task performance with a greater number of omission errors and more frequent sequentially occurring omission errors. Accordingly, these findings suggest that failures in the ability to maintain attentional vigilance may, in part, underlie mTBI-related cognition deficits.  相似文献   

Determination of the swing technique characteristics and performance outcome relationship in golf driving for low handicap female golfers     

Susan J. Brown  Alan M. Nevill  Stuart A. Monk  Steve R. Otto  W. Scott Selbie  Eric S. Wallace 《Journal of sports sciences》2013,31(14):1483-1491

Abstract

Previous studies on the kinematics of the golf swing have mainly focused on group analysis of male golfers of a wide ability range. In the present study, we investigated gross body kinematics using a novel method of analysis for golf research for a group of low handicap female golfers to provide an understanding of their swing mechanics in relation to performance. Data were collected for the drive swings of 16 golfers using a 12-camera three-dimensional motion capture system and a stereoscopic launch monitor. Analysis of covariance identified three covariates (increased pelvis–thorax differential at the top of the backswing, increased pelvis translation during the backswing, and a decrease in absolute backswing time) as determinants of the variance in clubhead speed (adjusted r ² = 0.965, P < 0.05). A significant correlation was found between left-hand grip strength and clubhead speed (r = 0.54, P < 0.05) and between handicap and clubhead speed (r = ?0.612, P < 0.05). Flexibility measures showed some correlation with clubhead speed; both sitting flexibility tests gave positive correlations (clockwise: r = 0.522, P < 0.05; counterclockwise: r = 0.711, P < 0.01). The results suggest that there is no common driver swing technique for optimal performance in low handicap female golfers, and therefore consideration should be given to individual swing characteristics in future studies.  相似文献   

The effect of chalk on the finger–hold friction coefficient in rock climbing     

Arif Mithat Amca  Laurent Vigouroux  Serdar Aritan  Eric Berton 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(4):473-479

The main purpose of this study was to examine the effect of chalk on the friction coefficient between climber's fingers and two different rock types (sandstone and limestone). The secondary purpose was to investigate the effects of humidity and temperature on the friction coefficient and on the influence of chalk. Eleven experienced climbers took part in this study and 42 test sessions were performed. Participants hung from holds which were fixed on a specially designed hang board. The inclination of the hang board was progressively increased until the climber's hand slipped from the holds. The angle of the hang board was simultaneously recorded by using a gyroscopic sensor and the friction coefficient was calculated at the moment of slip. The results showed that there was a significant positive effect of chalk on the coefficient of friction (+18.7% on limestone and +21.6% on sandstone). Moreover sandstone had a higher coefficient of friction than limestone (+15.6% without chalk, +18.4% with chalk). These results confirmed climbers' belief that chalk enhances friction. However, no correlation with humidity/temperature and friction coefficient was noted which suggested that additional parameters should be considered in order to understand the effects of climate on finger friction in rock climbing.  相似文献