Simultaneous measurement of back and front foot ground reaction forces during the same delivery stride of the fast-medium bowler

Six male cricket bowlers (mean +/- s(mean): age 23.5 +/- 1.3 years; height 1.83 +/- 0.04 m; body weight 826 +/- 20 N) performed their typical bowling action at a set of stumps positioned at standard pitch length (20.1 m). A specially designed force platform rig allowed the correct positioning of two force platforms to be achieved beneath an outdoor polyflex runway (0.017 m depth) for each player's delivery stride pattern. For the back foot, the peak vertical ground reaction force was 1.95 +/- 0.08 kN (2.37 +/- 0.14 BW) and the braking force was 0.77 +/- 0.12 kN (0.94 +/- 0.16 BW). For the front foot, the peak vertical force was 4.80 +/- 0.92 kN (5.75 +/- 0.98 BW) and the braking force was 2.93 +/- 0.56 kN (3.54 +/- 0.67 BW). The mean peak vertical loading rate for front foot contact was 205 +/- 52.8 kN x s(-1) (249 +/- 64 BW x s(-1)) with mean values ranging from 81 to 446 kN x s(-1) (98 to 540 BW x s(-1)). The range for back foot contact was much smaller, 25-70 kN x s(-1) (30-85 BW x s(-1)), with a mean of 41.7 +/- 7.10 kN x s(-1) (50.6 +/- 8.6 BW x s(-1)). Mean peak impact occurred 24 ms after touchdown for the back foot and 16 ms after touchdown for the front foot. At impact, mean peak loading rates were greater for the front foot at 246 kN x s(-1) (298 BW x s(-1)), with a range of 80-483 kN x s(-1) (98-534 BW x s(-1)), than for the back foot at 65 kN x s(-1) (79 BW x s(-1)), with a range of 40-84 kN x s(-1) (49-110 BW x s(-1)).     

Type of Feedback and Young Children's Performance on Computer Presented Reading Readiness Activities

Summary Forty children, between the ages of three years ten months and four years six months and with a mean age of four years three months, did computer‐presented reading‐readiness activities under different pre‐activity and feedback conditions. The children were randomly allocated within sexes to four groups. Group 1 listened to a story which involved a teddy bear character called BJ Bear and then did reading‐readiness activities such that the smiling face of the bear appeared on the screen and a tune played when they responded correctly, and the sad face of the bear when they were incorrect. Group 2 listened to the story and then did the activities with the smiling face of the bear and a tune when correct, but with nothing when they were wrong. Group 3 did not receive the story, but did the activities with both the smiling face of the bear and a tune when correct, and the sad face of the bear when incorrect. Group 4 also did not receive the story and did the activities with the smiling face of the bear and a tune when correct, but with nothing when they were wrong. Overall it was found that children did significantly better if given the story about BJ before the activities. There was also a significant interaction between the story condition, feedback for incorrect responses and sex such that performance was better for all with‐story groups except in the case of boys with no feedback.     

Dribble files: Methodologies to evaluate learning and performance in complex environments

Research in the area of technology learning environments is tremendously complex. Tasks performed in these contexts are highly cognitive and mostly invisible to the observer. The nature of performance in these contexts is explained not only by the outcome but also by the process. However, evaluating the learning process with respect to tasks involving technology is difficult to measure objectively. As a result, audit trails (also called log or dribble files) are becoming extremely valuable tools in evaluating learning and performance in complex environments. This article reviews efforts of researchers in various areas, describes the nature of research using dribble files, and provides a framework on which investigators might build evaluations.     

案例教学在中等职业学校体育教学中的运用

在中等职业学校体育教学实践的基础上,针对中等职业学生的特点和具体情况进行教学改革.介绍了消除“综合失调症“、消除学生“心理障碍“两种体育教学案例的主要教学步骤与方法.     

A comparison of visual search strategies of elite and non-elite tennis players through cluster analysis

Considerable research has documented that successful performance in interceptive tasks (such as return of serve in tennis) is based on the performers’ capability to capture appropriate anticipatory information prior to the flight path of the approaching object. Athletes of higher skill tend to fixate on different locations in the playing environment prior to initiation of a skill than their lesser skilled counterparts. The purpose of this study was to examine visual search behaviour strategies of elite (world ranked) tennis players and non-ranked competitive tennis players (n = 43) utilising cluster analysis. The results of hierarchical (Ward’s method) and nonhierarchical (k means) cluster analyses revealed three different clusters. The clustering method distinguished visual behaviour of high, middle-and low-ranked players. Specifically, high-ranked players demonstrated longer mean fixation duration and lower variation of visual search than middle-and low-ranked players. In conclusion, the results demonstrated that cluster analysis is a useful tool for detecting and analysing the areas of interest for use in experimental analysis of expertise and to distinguish visual search variables among participants’.     

美国爱达荷州体育教师标准简介

通过对美国爱达荷州新近颁布的体育教师标准的分析与归纳，阐述了美国基础体育教育人才培养和管理的专业标准以及基础体育教育领域的新思想、新观念，以求对我国在基础体育教育人才培养方面的科学决策和管理有所启示。     

Enhancement of anatomical learning and developing clinical competence of first‐year medical and allied health profession students

Hands‐on educational experiences can stimulate student interest, increase knowledge retention, and enhance development of clinical skills. The Lachman test, used to assess the integrity of the anterior cruciate ligament (ACL), is commonly performed by health care professionals and is relatively easy to teach to first‐year health profession students. This study integrated teaching the Lachman test into a first‐year anatomy laboratory and examined if students receiving the training would be more confident, competent, and if the training would enhance anatomical learning. First‐year medical, physician assistant and physical therapy students were randomly assigned into either the intervention (Group A) or control group (Group B). Both groups received the course lecture on knee anatomy and training on how to perform the Lachman test during a surface anatomy class. Group A received an additional 15 minutes hands‐on training for the Lachman test utilizing a lightly embalmed cadaver as a simulated patient. One week later, both groups performed the Lachman test on a lightly embalmed cadaver and later completed a post‐test and survey. Students with hands‐on training performed significantly better than students with lecture‐only training in completing the checklist, a post‐test, and correctly diagnosing an ACL tear. Students in Group A also reported being more confident after hands‐on training compared to students receiving lecture‐only training. Both groups reported that incorporating clinical skill activities facilitated learning and created excitement for learning. Hands‐on training using lightly embalmed cadavers as patient simulators increased confidence and competence in performing the Lachman test and aided in learning anatomy. Anat Sci Educ 7: 181–190. © 2013 American Association of Anatomists.     

浅谈田径教学中的优化组合

在总结传统教学经验的基础上，对教师的知识结构、教学内容、教学方法、实践性教学以及教学评价等进行优化组合，指出优化组合是田径教学改革的关键，优化教师知识结构是田径教学改革的前提和基础，优化课程结构和教学内容是田径教学改革的重点。     

计算机多媒体技术在体育教育中的运用

利用文献资料法、调查研究法对计算机多媒体技术在体育教学中的应用进行了分析 ,从中发现计算机多媒体技术的开发利用有利于体育教师的理论教学和教案撰写 ,有利于运动训练中各种数据的收集与运用 ,有利于体育教师职后教育中各种知识的掌握 ,是未来社会体育教育中应用广泛的现代化教学手段。     

Embedded programming and real-time signal processing of swimming strokes

The research outlined in this paper was conducted to allow real-time processing, transmission and presentation of data to swimming coaches and subsequently their swimmers in a training environment, focused on providing information relevant to strokes in free swimming. This was achieved using a wearable wireless sensor and embedded programming techniques, using accelerations involved in the swimming stroke to provide relevant features for coaches. Current methods used do not offer real-time response to coaches, which results in the lack of real-time feedback and significantly increased post-session analysis time. Filtering and signal processing algorithms are described here, which allow real-time data analysis to be embedded within a wireless sensor node. The system significantly reduces the time for processing acquired data and has delivered a novel monitoring device suitable for operation within the harsh environment of the pool.