Understanding teachers: the potential and possibility of discourse analysis

Understanding the ways in which teachers make sense of what they do and why is critical to a broader understanding of pedagogy. Historically, teachers have been understood through the thematic and content analysis of their beliefs or philosophies. In this paper, we argue that discourse analysis (DA) involves a much finer-grained analysis of the ‘lifeworlds’ of teachers and, in our view, provides a more detailed canvas from which inferences can be made. Our argument is structured in four parts. We begin by locating DA within the physical education (PE) literature and discuss what others have referred to as its relatively modest use. Following our location of DA, we outline a conceptual framework that we regard as useful, which contains six interrelated principles. We then introduce the idea of interpretive repertoires, which we consider to have particular explanatory power as well as being a sophisticated way to represent the subjectivities of PE teachers. Finally, we discuss the methodological strengths of interpretive repertoires. The paper concludes with a discussion on the theoretical and practical merits of adopting DA to analyse problems within PE.     

Affective response to gambling promotions during televised sport: A qualitative analysis

Gambling promotions extensively punctuate contemporary televised sport broadcasts and concerns have been raised about their potential impacts on vulnerable groups. Research suggests advertising can shape individuals’ emotions, or affect, towards a product/brand and can subsequently influence purchasing decisions. Consequently, understanding how promotion of gambling influences sport viewers is an important although sparsely addressed area of research. This paper presents exploratory research on affective responses towards gambling promotions displayed during televised sport. Eight online focus groups were conducted with a sample of regular sports viewers in Queensland, Australia. Participants were exposed to a variety of gambling promotions used in National Rugby League match telecasts. Utilising adaptive theory, themes reflecting affective responses to each promotional technique were identified. A range of positive and negative affective responses were identified including arousal, joy, anger and worry. A conceptual model representing emergent affective response categories, message delivery techniques and moderating variables is proposed to inform a broader future research agenda examining how gambling promotions during televised sport influence affective response and concomitant gambling intention.     

Long-term impact of the Tokyo 1964 Olympic Games on sport participation: A cohort analysis

The sport participation rate has been shown to decrease with age in many countries. In Japan, however, the elderly sport participation rate has increased over the last decade and is the highest among all Japanese. This study investigated whether the cohort effect generated by the shared experience of hosting the Tokyo 1964 Olympic Games during their youth can explain the increased sport participation of elderly Japanese. Data from the Japanese National Sport-Life Survey over 20 years were analyzed through regression analysis. The results show that, after controlling for demographics and other determinants of sport participation, individuals who experienced the Tokyo 1964 Olympic Games participated in sport more frequently than other generations.     

Fan response to the identity threat of potential team relocation

Group identities do not remain stable over time and team identity is no exception. As researchers have acknowledged team identity formation and maintenance as ongoing processes, it is equally important to explore how fans navigate threats to team identity. The purpose of this study is to understand how fans’ team identity was impacted by identity threat. The authors used digital ethnography to investigate how fans of the National Football League (NFL) Rams processed the identity threat presented by the team’s potential cross-country relocation from St. Louis, Missouri to Los Angeles, California. Based on analysis of fans’ real-time responses (via online discussion board), the authors found that fans’ team identity changed in meaning and importance as a result of the threat. The findings have theoretical implications for the study of team identification, particularly concerning the evaluative nature of identity, the relationship between team and place identity, and the inclusiveness of the group in team identity.     

Determinants of countermovement jump performance: a kinetic and kinematic analysis

Abstract

This study aimed to investigate the contributions of kinetic and kinematic parameters to inter-individual variation in countermovement jump (CMJ) performance. Two-dimensional kinematic data and ground reaction forces during a CMJ were recorded for 18 males of varying jumping experience. Ten kinetic and eight kinematic parameters were determined for each performance, describing peak lower-limb joint torques and powers, concentric knee extension rate of torque development and CMJ technique. Participants also completed a series of isometric knee extensions to measure the rate of torque development and peak torque. CMJ height ranged from 0.38 to 0.73 m (mean 0.55 ± 0.09 m). CMJ peak knee power, peak ankle power and take-off shoulder angle explained 74% of this observed variation. CMJ kinematic (58%) and CMJ kinetic (57%) parameters explained a much larger proportion of the jump height variation than the isometric parameters (18%), suggesting that coachable technique factors and the joint kinetics during the jump are important determinants of CMJ performance. Technique, specifically greater ankle plantar-flexion and shoulder flexion at take-off (together explaining 58% of the CMJ height variation), likely influences the extent to which maximal muscle capabilities can be utilised during the jump.     

Mid-flight lateral trunk bending increased ipsilateral leg loading during landing: a center of mass analysis

Increased lateral trunk bending to the injured side has been observed when ACL injuries occur. The purpose was to quantify the effect of mid-flight lateral trunk bending on center of mass (COM) positions and subsequent landing mechanics during a jump-landing task. Forty-one recreational athletes performed a jump-landing task with or without mid-flight lateral trunk bending. When the left and right trunk bending conditions were compared with the no trunk bending condition, participants moved the COM of the upper body to the bending direction, while the COM of the pelvis, ipsilateral leg, and contralateral leg moved away from the bending direction relative to the whole body COM. Participants demonstrated increased peak vertical ground reaction forces (VGRF) and knee valgus and internal rotation angles at peak VGRF for the ipsilateral leg, but decreased peak VGRF and knee internal rotation angles at peak VGRF and increased knee varus angles at peak VGRF for the contralateral leg. Mid-flight lateral trunk resulted in an asymmetric landing pattern associated with increased ACL loading for the ipsilateral leg. The findings may help to understand altered trunk motion during ACL injury events and the discrepancy in ACL injuries related to limb dominance in badminton and volleyball.     

髓鞘内不同浓度甘丙肽拮抗剂对屈肌运动的相反效应

目的 :了解脊髓中不同剂量甘丙肽拮抗剂M35和M40对甘丙肽抑制屈肌运动作用的影响。方法 :电刺激小腿腹神经引起小腿屈肌收缩时 ,观察髓鞘内联合注入甘丙肽和不同浓度拮抗剂时屈肌张力的改变。结果注入0 0 1、 0 0 3及 0 1μmol/LM35时 ,0 1μmol/L甘丙肽对屈肌张力抑制率从 - 2 9 2 %改变至± 15 1%、 - 2 5 %及 -17 8% ;但 1及 3μmol/L的M35使甘丙肽抑制率分别增强至 - 5 1 9%及 - 6 5 6 %。而给于 0 0 1及 0 0 3μmol/LM40时 ,甘丙肽抑制率增至 - 5 6 7%及 - 41 6 % ,0 3、 1及 3μmol/LM40使甘丙肽抑制率分别改变为 - 6 8%、 +12 2 %及 +30 4%。结论　低浓度M35为甘丙肽拮抗剂 ,高浓度M35有甘丙肽激动剂作用 ;低浓度M40为甘丙肽激动剂 ,高浓度M40有甘丙太拮抗剂效应。脊髓神经元可能存在不同甘丙肽亚型受体。     

教师的作用与修养

本文论述二十一世纪教师所起的作用、应该具备的修养,并指出如何才能达到。     

The penalty throw in water polo: A cinematographic analysis

Three‐dimensional (3‐D) high‐speed cinematography was used to record the penalty throw in water polo by six elite male (M) and six elite female (F) players. The direct linear transformation technique (DLT) was used in the 3‐D space reconstruction from 2‐D images recorded via laterally placed phase‐locked cameras operating at 200 Hz. Five of the twelve subjects lifted the ball from underneath at the start of the throw whilst the remaining subjects opted for a rotation lift. As the ball was brought behind the head the females used very little hip and shoulder rotation compared to the male players so that four of the six female subjects were square on to the target at the rear point. At the completion of the backswing the wrist was flexed to a similar angle (M‐162°; F‐158°); the elbow angle showed significantly greater flexion for females (85°) than males (107°).

During the forward swing, from rear point to release, the wrist joint of the female players flexed from a rear point angle of 158° to 148° at release. The wrist movement for male subjects was different from the females in that it flexed from 162° to 147°, 0.10 s prior to release and then extended to 159° at palmar release before again flexing to 156° at release. The amount of elbow extension during the forward swing was 48° for both groups; however, the females actually released the ball with the forearm vertical (89°) compared to the male forearm angle of 78°. Maximum angular velocity of the wrist and elbow occurred at release for 9 of the 12 subjects. Both the wrist and elbow joints (F‐148°; M‐156° at wrist and F‐126°; M‐148° at elbow) demonstrated greater flexion at release in female subjects, compared with males. Maximum linear endpoint velocities for the forearm and hand segments occurred at ball release resulting in mean ball velocities of 19.1 m s ^‐1 and 14.7 m s^{‐ 1} for male and female subjects respectively.     

Biomechanical analysis of the different classifications of the Functional Movement Screen deep squat test

The purpose of this study is to examine the peak sagittal plane joint angles and joint moments of the lower extremity during the deep squat (DS) movement of the Functional Movement Screen (FMS) to assess differences between the classifications (1,2,3). Twenty-eight participants volunteered for the study and were screened to assess their FMS score on the DS task. All participants underwent a quantitative movement analysis performing the FMS DS movement at a self-selected speed. The participants in Group 3 exhibited greater dorsiflexion excursion compared to those in Group 1. Participants in Group 3 had greater peak knee flexion and knee flexion excursion than those in Group 2 who exhibited more than the participants in Group 1. Group 3 also exhibited a greater peak knee extension moment compared to Group 1. At the hip, Groups 3 and 2 exhibited greater peak hip flexion, hip flexion excursion and peak hip extension moment compared to Group 1. Thus, it appears that individuals who score differently on the deep squat as determined by the FMS exhibit differences in mechanics that may be beneficial in assessing strategies for interventions. Future research should assess how fundamental changes in mobility and stability independently affect DS performance.     

拉拉队效应的运动心理学分析

拉拉队对运动员的心理施以正负效应,进而影响运动员的成绩。拉拉队可分为简易拉拉队、表演型拉拉队、影子拉拉队等层次,不同层次的拉拉队产生不同的效应。根据不同的效应,在部署拉拉队时可采用不同的策略。根据国外经验,有必要组建专业拉拉队,走专业化、产业化之路。     

优秀女子三级跳远运动员速度变化特点的研究

主要采用摄像、录象解析法和文献资料法,对我国部分优秀女子三级跳远运动员在试跳过程中速度变化的特点以及每一跳速度变化情况进行分析,同时与世界优秀运动员进行对比。探讨女子三级跳远技术中各跳之间速度分配的特点。     

The influence of the vaulting table on the handspring front somersault

The traditional “horse” was replaced by a new vaulting “table” in artistic gymnastics competitions in 2001.The aim of this study was to determine whether the table led to a change in vaulting technique. This was achieved by comparing three-dimensional video-based analyses (50 Hz) of selected biomechanical discrete and continuous variables across four elite male gymnasts performing a series of handspring front somersault vaults on the traditional horse and the new table. Individual joint and inter-segment coupling (continuous relative phase) were used to quantify techniques used on the two apparatuses. Differences were attributed in part to the design and construction of the new table. No differences were observed for the approach and take-off from the board. Significant differences in hip flexion at board take-off and strike angle on the table were observed. One of the effects of the latter was an increase in vertical take-off velocity compared with the horse. Individual strategies were observed in hip and shoulder coordination patterns that were obscured when group data were considered. Close monitoring of the evolution of skill on this new apparatus is paramount for gymnastics coaching, and further studies of current elite competitive vaulting techniques are required.     

Application of functional principal component analysis in race walking: An emerging methodology

This study considered the problem of identifying and evaluating the factors of individual performance during race walking. In particular, the study explored the use of functional principal component analysis (f-PCA), a multivariate data analysis, for assessing and classifying the kinematics and kinetics of the knee joint in competitive race walkers. Seven race walkers of international and national level participated to the study. An optoelectronic system and a force platform were used to capture three-dimensional kinematics and kinetics of lower limbs during the race walking cycle. Functional principal component analysis was applied bilaterally to the sagittal knee angle and net moment data, because knee joint motion is fundamental to race walking technique. Scatterplots of principal component scores provided evidence of athletes' technical differences and asymmetries even when traditional analysis (mean ± s curves) was not effective. Principal components provided indications for race walkers' classification and identified potentially important technical differences between higher and lower skilled athletes. Therefore, f-PCA might represent a future aid for the fine analysis of sports movements, if consistently applied to performance monitoring.     

A distributional analysis of the effect of physical exercise on a choice reaction time task

Abstract

The aim of this study was to examine the facilitating effects of physical exercise on the reaction process. Eleven participants with specific expertise in decision-making sports performed a choice reaction time task during moderate sub-maximal exercise (90% of their ventilatory threshold power). Participants were tested at rest and while cycling. During exercise, the participants were faster, without being more variable. We suggest that the effect of exercise on cognitive performance was due to a major generalized improvement of the whole distribution of response time and, although the benefit effect was small, it was consistent throughout the entire range of reaction times.     

The Mechanics of Batting: Analysis of Ground Reaction Forces and Selected Lower Extremity Kinematics

Abstract

The purpose of this study was to examine variations in ground reaction forces and selected lower extremity kinematics during the stride and swing phases of batting. High speed photography (100 fps) employing direct linear transformation methodology and a force plate were used to record three-dimensional kinematic and kinetic data for 7 female fast pitch softball batters. Mean vertical forces (F_z) of the right or rear foot increased to approximately 1 BW during the stride. Once the left or forward foot made contact with the ground after completion of the stride, right F_z forces decreased to .43 BW while left F_z forces rapidly increased to 1.6 BW at contact. The mean decrease in right F_z forces from peak force until contact was 55%, and the ratio of left to right F_z forces; at impact was 3.67:1. Right mediolateral forces (F_x) were exerted laterally, away from the batter, and were responsible for initiating movement of the body toward the pitched ball. As the left foot made contact with the ground at completion of the stride, left F_x forces were exerted laterally toward the pitched ball. The reaction to these forces retarded the batter's forward momentum, increased stability, and caused the left hip and knee to extend as contact approached. Right and left anteroposterior forces (F_y) acted in opposite directions (right foot pushing backward, left foot pushing forward), and were responsible for rotating the hips and upper body in a counterclockwise direction toward the pitched ball. Horizontal angular deceleration of both thighs just prior to contact was due, in part, to a decrease in these forces. These data may prove helpful when attempting to identify atypical batting patterns, and when considering improvements in shoe design. In the latter instance, force production and stability may be enhanced by aligning the cleats along the lines of action of the applied resultant shear forces.     

The Submaximal Lateral Shuffle Test: A reliability and sensitivity analysis

ABSTRACT

Lateral ankle stability and how it changes in different footwear has been investigated for years. Research, however, has shown a lack of reliability or sensitivity of available methodologies. This study aimed to evaluate the test-retest reliability and sensitivity of a novel lateral stability protocol, the Submaximal Lateral Shuffle Test (SLST). We recruited 11 and 40 participants to assess reliability and sensitivity of the SLST, respectively. Participants performed the SLST in footwear that differed in collar height and upper stiffness. ICC values showed good to excellent reliability in peak ankle angles and moments, ground reaction forces, impulses, stance time, and performance time. Significantly lower peak inversion and adduction angles and lower medio-lateral push off peak forces were found in the high cut shoes compared to the low cut shoes. The medio-lateral landing peak force showed lower forces in the high cut shoes. The smallest worthwhile change indicated meaningful differences in 70.0–82.5% of participants for inversion, adduction, medio-lateral landing peak, and push off peak forces. These results, however, were not systematic such that there was not a consistent direction of the difference for all participants. In conclusion, the SLST is a promising protocol to further investigate lateral stability in footwear.     

对技巧女三膝抛直体后空翻两周下动作的动力学和动动学特征的研究

本文采用高速摄影与三维测力同步的方法，对技巧女三膝抛直体后空翻两周下动作进行了定量测试，揭示了该动作的动力学和运动学特征，进而提出了完成该动作的最佳配合技术特点．     

Shoe drop reduction influences the lower limb biomechanics of children tennis players during an open stance forehand: A longitudinal study

Compared to traditional tennis shoes, using 0-drop shoes was shown to induce an immediate switch from rear- to forefoot strike pattern to perform an open stance tennis forehand for 30% of children tennis players. The purpose of the study was to examine the long-term effects of a gradual reduction in the shoe drop on the biomechanics of children tennis players performing open stance forehands. Thirty children tennis players participated in 2 laboratory biomechanical test sessions (intermediate: +4 months and final: +8 months) after an inclusion visit where they were randomly assigned to control (CON) or experimental (EXP) group. CON received 12-mm-drop shoes twice, whereas EXP received 8?mm then 4-mm-drop shoes. Strike index indicated that all CON were rearfoot strikers in intermediate and final test sessions. All EXP were rearfoot strikers in intermediate test session, but half the group switched towards a forefoot strike pattern in final test session. This switch resulted in a decreased loading rate of the ground reaction force (?73%, p?=?.005) but increased peak ankle plantarflexors moment (+47%, p?=?.050) and peak ankle power absorption (+107%, p?=?.005) for these participants compared with CON. Biomechanical changes associated with the long-term use of partial minimalist shoes suggest a reduction in heel compressive forces but an increase in Achilles tendon tensile forces.     

The Effects of Muscular Fatigue on the Kinetics of Sprint Running

Abstract

In order to compare the kinematic and kinetic effects of fatigue on the mechanics of sprint running, 15 male subjects were filmed in the saggital plane while performing a short (50 meter) maximal exertion sprint and a long (400 meter) fatiguing sprint. The short sprint was filmed at 40 meters, while the long sprint was filmed at 40 and 380 meters. The films were reduced utilizing a digitizer coupled to a computer terminal. Analysis results were generated via a human motion analysis program. Kinematic and kinetic results were entered into the statistical analysis as differences between non-fatigued and fatigued values. Initially, quality of the performance (measured by the change in horizontal velocity of the body center of gravity) was statistically related to change in the kinetic variable of integrated muscle moment at each of the body joints. The kinetic variables found to be significant were then statistically compared to logically related changes in kinematic variables (temporally adjacent or concurrent). Changes in the generated moments about the hip and knee during ground contact were found to be related to the quality of the performer. Kinematic changes related to the significant moment changes indicated that, while the better sprinter (smaller velocity loss) closely maintained the kinetic and kinematic patterns, the poorer sprinter (larger velocity loss) inefficiently deviated in both areas. The lack of significance between the changes in upper limb moments and change in average velocity indicated that productive arm effort does not affect the level of performance in the fatigued condition.