The associations of selected technical parameters with discus throwing performance: A cross-sectional study

The aim of this study was to identify associations between discus throwing performance and the technical parameters of: hip–shoulder and shoulder–arm separation, trunk forward–backward tilt, and throwing-arm elevation angles. Video data of male and female discus throwers' competitive performances were captured during major competitions. Real-life three-dimensional coordinates of 21 body landmarks, and the discus's centre, were obtained for 94 trials using the direct linear transformation procedure. Each technical parameter was reduced at six critical instants. The trend of each parameter across four standards of performance was analysed separately for both sexes. For the female throwers, hip–shoulder and shoulder–arm separations after the flight phase, as well as forward–backward trunk tilts at the beginning and end of the throwing procedure were associated with performance. For male throwers, only the hip–shoulder separation immediately before the flight phase was associated with performance. These findings suggest that the relationships between technical parameters and discus throwing performance are different for males and females. Our results suggest that elite female discus throwers are reliant on effective technique throughout the throwing procedure to achieve long distances, whereas male discus throwers may have a relatively homogeneous technique, and a dependence on physical strength to achieve their long throws.     

The relationship between discus throwing performance and combinations of selected technical parameters

The aim of this study was to determine the relationship between discus throwing performance and the following technical parameters: hip-shoulder and shoulder-arm separation, trunk forward-backward tilt, throwing-arm elevation angles, and the absolute and relative throwing procedure phase times. Videographic data of 51 male and 53 female discus throwers' competitive performances were captured during major meets. The three-dimensional coordinates of 21 body landmarks and the discus were obtained for each thrower's best trial using direct linear transformation. The technical parameters were reduced from the three-dimensional data at six critical instants during the throwing procedure. Hierarchical stepwise multiple regression analyses were performed to determine the relative influence of linear combinations of the technical parameters on discus throwing performance. Specific techniques associated with linear combinations of certain technical parameters were identified using canonical correlations. Males and females were analysed separately. Suggestions for controlling the height of release and the vertical component of the speed of release using an effective technique are made.     

The relationship between discus throwing performance and combinations of selected technical parameters

The aim of this study was to determine the relationship between discus throwing performance and the following technical parameters: hip–shoulder and shoulder–arm separation, trunk forward–backward tilt, throwing-arm elevation angles, and the absolute and relative throwing procedure phase times. Videographic data of 51 male and 53 female discus throwers' competitive performances were captured during major meets. The three-dimensional coordinates of 21 body landmarks and the discus were obtained for each thrower's best trial using direct linear transformation. The technical parameters were reduced from the three-dimensional data at six critical instants during the throwing procedure. Hierarchical stepwise multiple regression analyses were performed to determine the relative influence of linear combinations of the technical parameters on discus throwing performance. Specific techniques associated with linear combinations of certain technical parameters were identified using canonical correlations. Males and females were analysed separately. Suggestions for controlling the height of release and the vertical component of the speed of release using an effective technique are made.     

对我国优秀男子铁饼运动员投掷技术的运动学分析

通过对我国优秀男子铁饼运动员旋转掷铁饼技术的速度结构特征和动作结构特征的初步分析,发现我国男子铁饼运动员与国外优秀运动员的主要差距是双支撑起转阶段和旋转阶段铁饼的速度损失较大。腾空和过渡时间长、肩髋柔韧性差、最后用力时机晚等是影响我国运动员铁饼速度发挥的主要因素。     

Sequences of upper and lower extremity motions in javelin throwing

Javelin throwing is technically demanding. Sequences of upper and lower extremity motions are important for javelin throwing performance. The purpose of this study was to determine the general sequences of upper and lower extremity motions of elite male and female javelin throwers. Three-dimensional kinematic data were collected for 32 female and 30 male elite javelin throwers during competitions. Shoulder, elbow, wrist, hip, knee, ankle, lower trunk, and upper trunk joint and segment angles were reduced for the best trial of each participant. Beginning times of 6 upper extremity and 10 lower extremity joint and segment angular motions were identified. Sequences of the upper and lower extremity motions were determined through statistical analyses. Upper and lower extremity motions of the male and female elite javelin throwers followed specific sequences (P?≤?0.050). Upper extremity motions of the male and female elite javelin throwers did not follow a proximal-to-distal sequence as suggested in the literature. Male and female elite javelin throwers apparently employed different sequences for upper and lower extremity motions (P?相似文献   

Comparison of sequence of trunk and arm motions between short and long official distance groups in javelin throwing

The purpose of this study was to determine the effects of sequences of the trunk and arm angular motions on the performance of javelin throwing. In this study, 32 male and 30 female elite javelin throwers participated and were separated into a short official distance group or a long official distance group in each gender. Three-dimensional coordinates of 21 body landmarks and 3 marks on the javelin in the best trial were collected for each subject. Joint center linear velocities and selected trunk and arm segment and joint angles and angular velocities were calculated. The times of the initiations of the selected segment and joint angular motions and maximum angular velocities were determined. The sequences of the initiations of the selected segment and joint angular motions and maximum angular velocities were compared between short and long official distance groups and between genders. The results demonstrated that short and long official distance groups employed similar sequences of the trunk and arm motions. Male and female javelin throwers employed different sequences of the trunk and arm motions. The sequences of the trunk and arm motions were different from those of the maximal joint center linear velocities.     

力量素质与铁饼成绩的灰色关联分析

本文通过对天津体院男、女铁饼运动员,集训队部分男铁饼运动员以及优秀铁饼运动员张景龙的各项力量素质与铁饼成绩的灰色关联分析,找出了影响不同类型运动员铁饼成绩的主要优势因素;并通过对他们有关力量素质的对比分析,论述了各类铁饼运动员应有不同的中心训练任务和训练方法。     

对我国优秀女子铁饼运动员投掷技术的运动学分析

目前,我国优秀女子铁饼运动员的成绩与世界一流水平相比,存在不少差距。本文将第6届全运会优秀女子铁饼运动员的技术动作分为4个时相,对其运动学特征进行解析,为改进技术动作、提高运动成绩提供参考依据。     

我国优秀女子铁饼运动员投掷过程中 铁饼的运动学特征分析

采用文献资料法、影片解析法、问卷调查法和对比分析法,对6名运动员最好的一次投掷技术进行解析,对投掷过程中铁饼的运动学特征进行分析和讨论得出相应结论,认为6名运动员在心速度变化、旋转技术节奏、铁饼运行轨迹等方面各有其特点和不足。     

我国优秀女子铁饼运动员最后用力阶段身体重心运动节奏特征分析

采用文献资料法、三维录像解析法以及数理统计等研究方法,以2007年全国田径锦标赛女子铁饼前8名的投掷技术为研究对象,对我国优秀女子铁饼运动员在掷铁饼最后用力阶段身体重心的时间、空间以及速度节奏进行了定量分析.同时采用Person相关分析对我国优秀女子铁饼运动员最后用力阶段身体重心的时间、空间以及速度的变化与投掷成绩进行了检验,提出了我国优秀女子铁饼运动员最后用力阶段身体重心节奏变化的量化指标.     

Release parameters at the foul line and the official result in javelin throwing

Range in javelin throwing is determined by the release parameters and aerodynamic factors. The current study was designed to investigate the effects of release speed, release angle and uncorrected angle of attack measured at the foul line on the official javelin throwing result. The data were collected in international competitions for 26 elite male and 15 elite female javelin throwers (total 248 throws). Multiple regression models were constructed to predict the range of throw for a) individual throwers, b) a group of throwers using the mean value for each thrower in the analysis, and c) all individual throws registered for each gender separately. The data collection was carried out using a computerised photocell gate that consists of two invisible infrared walls two metres apart, perpendicular to the throwing direction. Release speed was found to have the highest correlation with the official throwing result. The three release parameters accounted for 56% of the variance in the official result for the male and 51% for the female throwers. For individual male and female throwers, the variance explained by the model was between 46 and 87%. Among the individual male throwers an increase of 1 m.s-1 in the release speed from 29 to 30 m.s-1 was calculated to increase the official result between 2.12 to 6.14 m while among the female throwers the effect of increase from 24 to 25 m.s-1 in the release speed was from 2.25 to 3.68 m. The study emphasises the importance of investigating javelin throwing biomechanics on an individual thrower basis.     

我国女子铁饼运动员最后用力阶段技术分析

掷铁饼最后用力阶段环节枝术是指在掷铁饼的最后加速阶段,身体各环节为将铁饼以最快的出手初速度和适宜的角度掷出,而采用的动作方法。本文运用三维摄像方法对我国8名优秀女子掷铁饼运动员的最后用力技术进行研究,利用三维运动快速解析系统,获取数据,经皮尔森相关分析获得我国优秀女子掷铁饼运动员最后用力技术的各个环节中与铁饼成绩相关密切的指标。     

Athletics

The purposes of this study were to investigate (1) the relationships between official distance and selected ground reaction measures during discus throwing; and (2) the relationships between selected ground reactions and selected lower extremity joint kinetics. Three high‐speed video cameras and three force plates were used to collect three‐dimensional videographic and force plate data in this study. An inverse dynamic model was used to determine the lower extremity kinetics. Multiple regression analyses were conducted to determine relationships of the selected kinematic and kinetic measures with the official distance. Official distance was significantly correlated with ground reaction forces on the left foot during the first single‐support phase, on the right foot during the second single‐support phase and delivery phase, and on the left foot during the delivery phase. Also, the right‐hip extension and internal rotation moments and left‐knee extension moment during the delivery phase were significantly correlated with official distance. These results suggest that discus throwers should drive vigorously forward during the first single‐support phase and increase the landing impact force on the right foot after flight. Also they should increase forward and rightward ground reaction force on the right foot and backward and vertical force on the left foot by powerful right‐hip extension and internal rotation and left‐knee extension during the delivery phase. These results provide critical information regarding the training of discus‐throwing techniques, and the direction of future biomechanical studies on this event.     

我国优秀女子铁饼运动员旋转过程中身体重心变化的三维运动学分析

用三维运动学分析的方法对我国 8名优秀女子铁饼运动员的旋转技术进行评定 ,在一些参数上与世界优秀运动员对照 ,用身体重心运动变化的多项指标揭示旋转技术的规律与特征 ,找出我国女子铁饼运动员旋转技术的优势与不足     

我国女子铁饼优秀运动员过渡和最后用力阶段技术动力学及运动学的特征

时目前我国3名优秀女子铁饼运动员投掷技术进行同步研究发现,宋爱民存在腾空时间短、重心高、右脚着地早、上下肢扭紧差,最后用力阶段重心向投掷方向移动速度快、左右脚在垂直方向和前后方向的力较大、力量的向前行较好;孙太凤缓冲时间较短、右腿蹬伸充分、垂直方向和向前的力量较大;李艳凤过渡阶段上下肢扭紧好、身体后倾角度大、右脚着地对地面冲击力大、左右方向的力较大、力量在左右腿之间移动幅度大、没有转化为向前或者垂直方向的力量,向前性差,蹬伸不充分.     

Changing throwing pattern: instruction and control parameter

The purpose of this study was to determine the effects of instruction and scaling up a control parameter (velocity of throw) on changes in throwing pattern. Sixty adult female throwers (ages 20-26 years) were randomly placed into one offour practice conditions: (a) scale up on velocity with no instruction, (b) maintain constant velocity with no instruction, (c) maintain constant velocity with instruction, and (d) scale up on velocity with instruction. Participants in each condition were required to practice throwing with the nondominant arm twice per week for 5 weeks (10 sessions). Practice consisted of 20 throws per session. Participants in conditions including instruction were encouraged to rotate the trunk in an attempt to take advantage of the order parameter. Analysis indicated that each condition improved relative to use of the open kinetic chain. However, participants who increased velocity were more likely to attain maximum use of the order parameter with less practice. Additionally, throwers who increased velocity without instruction attained an optimal pattern of complete distal lag one session earlier than those who increased velocity with instruction. Data indicated that for those conditions without instruction, hand to forearm lag (H-F lag) occurred before humeral lag. It was concluded that emphasizing proximal movement (trunk rotation) without increasing velocity does not result in a final pattern that uses H-F lag.     

中外优秀女子铁饼运动员身体素质指标的比较分析

采用关联分析方法,对中国8名优秀女子铁饼运动员的7项身体素质指标进行对比分析,找出各项身体素质指标对运动成绩影响的主次关系。在此基础上,与国外优秀女子铁饼运动员进行对比,从中发现我国女子铁饼运动员身体训练中的不足,并对今后的训练提出建议。     

Technique factors related to ball release speed and trunk injuries in high performance cricket fast bowlers

In this study we analysed technique, ball speed and trunk injury data collected at the Australian Institute of Sport (AIS) from 42 high performance male fast bowlers over a four year period. We found several notable technique inter-relationships, technique and ball speed relationships, and associations between technique and trunk injuries. A more front-on shoulder alignment at back foot contact was significantly related to increased shoulder counter-rotation (p < 0.001). Bowlers who released the ball at greater speeds had an extended front knee, or extended their front knee, during the front foot contact phase (p < 0.05). They also recorded higher braking and vertical impact forces during the front foot contact phase and developed those forces more rapidly (p < or =0.05). A maximum hip-shoulder separation angle occurring later in the delivery stride (p = 0.05) and a larger shoulder rotation to ball release (p = 0.05) were also characteristics of faster bowlers. Bowlers suffering lower back injuries exhibited typical characteristics of the 'mixed' technique. Specifically, the hip to shoulder separation angle at back foot contact was greater in bowlers who reported soft tissue injuries than in non trunk-injured bowlers (p = 0.03), and shoulder counter-rotation was significantly higher in bowlers who reported lumbar spine stress fractures than non trunk-injured bowlers (p = 0.01). The stress fracture group was also characterised by a larger hip angle at front foot contact and ball release, whereas a more flexed front knee at ball release characterised the non trunk-injured group.     

掷铁饼运动的历史沿革和发展趋势研究

本文通过文献资料法对掷铁饼运动的起源、发展趋势进行了系统的分析与论述。结果显示：掷铁饼运动起源于人类早期的生产劳动;掷铁饼技术大致经历原地投掷、上步投掷、侧向旋转投掷以及背向旋转投掷几个阶段;将来掷铁饼技术的发展趋势为：继续提高器械出手速度并保持良好的出手初始状态,加快和完善旋转技术,加强旋转与最后用力的衔接连贯,充分发挥基本技术原理与个人特点的完美结合。     

旋转掷铁饼技术中肩、髋、铁饼及人体重心的时空特征研究

运用近景动态立体摄像的方法 ,对我国优秀女子运动员完成旋转掷铁饼技术时的肩、髋、铁饼及人体重心的时空特征进行了三维分析。表明不同时空的肩、髋、铁饼及人体重心处于不同的位置 ,是与铁饼技术要求紧密相关的 ,破坏了各个时空中肩、髋、铁饼及人体重心的时空结构势必会影响掷铁饼技术、速度和最后的运动成绩 ;铁饼速度与人体重心速度的变化反映了旋转掷铁饼技术的节奏特征