我国优秀男子背越式跳高运动员起跳过程运动学因子及其对起跳效果的影响   总被引：2，自引：0，他引：2  

刘英梅  吕乙林 《广州体育学院学报》2003,23(2):54-57

起跳效果历来是专家、学及教练员关注的焦点。背越式跳高中助跑最后一步技动腿着地瞬间就巳进入了起跳。采用三维高速摄影和影片解折的方法，通过因子分析，探讨整个起跳过程内部诸因素之间的联系及其对起跳效果的影响。结果表明：背越式跳高起跳过程运动学特征可以用4个因子来表示，并通过回归方程的分析，指出我国优秀男子背越式跳高运动员要提高起跳效果，须增大蹬伸距离，提高蹬伸幅度，提高摆动腿平均摆动角速度，加大摆动力度和调整摆动腿制动时机。  相似文献   

Specific tackling situations affect the biomechanical demands experienced by rugby union players     

Elena Seminati  Dario Cazzola  Ezio Preatoni  Grant Trewartha 《Sports biomechanics / International Society of Biomechanics in Sports》2017,16(1):58-75

Tackling in Rugby Union is an open skill which can involve high-speed collisions and is the match event associated with the greatest proportion of injuries. This study aimed to analyse the biomechanics of rugby tackling under three conditions: from a stationary position, with dominant and non-dominant shoulder, and moving forward, with dominant shoulder. A specially devised contact simulator, a 50-kg punch bag instrumented with pressure sensors, was translated towards the tackler (n = 15) to evaluate the effect of laterality and tackling approach on the external loads absorbed by the tackler, on head and trunk motion, and on trunk muscle activities. Peak impact force was substantially higher in the stationary dominant (2.84 ± 0.74 kN) than in the stationary non-dominant condition (2.44 ± 0.64 kN), but lower than in the moving condition (3.40 ± 0.86 kN). Muscle activation started on average 300 ms before impact, with higher activation for impact-side trapezius and non-impact-side erector spinae and gluteus maximus muscles. Players’ technique for non-dominant-side tackles was less compliant with current coaching recommendations in terms of cervical motion (more neck flexion and lateral bending in the stationary non-dominant condition) and players could benefit from specific coaching focus on non-dominant-side tackles.  相似文献   

Fatigue increases ankle sprain risk in badminton players: A biomechanical study     

Alexis Herbaut  Julien Delannoy 《Journal of sports sciences》2020,38(13):1560-1565

ABSTRACT

Ankle sprains are the most common injury in regular badminton players and usually occur at the end of a match or training. The purpose of the present study was to examine the influence of fatigue produced by badminton practice on the lower limb biomechanics of badminton players. It was hypothesized that fatigue induces ankle kinematic and lower leg muscle activity changes which may increase the risk of ankle sprain. Ankle kinematics, ankle kinetics and muscles activities of 17 regular badminton players were recorded during lateral jumps before and after an intense badminton practice session. Post-fatigue, ankle inversion at foot strike and peak ankle inversion increased (+2.6°, p = 0.003 and +2.5°, p = 0.005, respectively). EMG pre-activation within 100 ms before foot landing significantly decreased after fatigue for soleus (?23.4%, p = 0.031), gastrocnemius lateralis (?12.2%, p = 0.035), gastrocnemius medialis (?23.3%, p = 0.047) and peroneus brevis (?17.4%, p = 0.036). These results demonstrate impaired biomechanics of badminton players when fatigue increases, which may cause a greater risk of experiencing an ankle sprain injury.  相似文献   

对足球移动能力训练的思考          下载免费PDF全文

毛燕平 《河北体育学院学报》2017,31(3):76-79

运用文献资料法、逻辑分析法和经验总结法,对足球运动员移动能力训练进行研究.指出,移动能力是足球技能的重要组成部分,与球员的比赛表现密切相关.在对移动方式特征和分类进行分析梳理的基础上,针对长期被忽视的发展感知能力和移动效果反馈两方面,提出足球移动能力训练的内容和重点,以及不同训练阶段的训练要点.认为,发展移动能力要符合力学原理、结合专项技术训练,最终实现训练能力向比赛能力的转化.  相似文献   

Influence of sex and limb dominance on lower extremity joint mechanics during unilateral land-and-cut manoeuvres     

Joshua T. Weinhandl  Bobbie S. Irmischer  Zachary A. Sievert  Kevin C. Fontenot 《Journal of sports sciences》2017,35(2):166-174

Limb dominance theory suggests that females tend to be more one-leg dominant and exhibit greater kinematic and kinetic leg asymmetries than their male counterparts, contributing to the increased risk of anterior cruciate ligament injury among female athletes. Thus, the purpose of this study was to examine the influences of sex and limb dominance on lower extremity joint mechanics during unilateral land-and-cut manoeuvres. Twenty-one women and 21 men completed land-and-cut manoeuvres on their dominant limb as well as their nondominant limb. Three-dimensional kinematics and kinetics were calculated bilaterally for the entire stance phase of the manoeuvre. Women performed land-and-cut manoeuvres with altered hip motions and loads as well as greater knee abduction at touchdown compared to men. Dominant limb land-and-cut manoeuvres where characterised by decreased hip flexion at touchdown as well as decreased hip flexion and adduction range of motion compared to nondominant land-and-cuts regardless of sex. The observed sex differences are consistent with previous research regarding mechanisms underlying the sex disparity in anterior cruciate ligament injury rates. However, observed differences regarding limb dominances appear somewhat arbitrary and did not suggest that the dominant or nondominant limb would be at increased risk of anterior cruciate ligament injury.  相似文献   

竞技健美操提臀类与分切类难度动作的运动学对比研究     

赵轩立  张晓莹  刘曦 《山东体育学院学报》2020,(1):82-88

高分值难度动作的选编是竞技健美操比赛运动员获胜的根本。作为难度组合的常用动作,提臀类与分切类难度动作在国际高水平赛事中选用甚多,两类动作技术的掌握对于运动员成套编排和训练以及难度分值的提升尤为重要。以高分值难度A207与A220为例,对提臀类与分切类难度动作进行运动学对比研究.比赛中两个难度区分度较低,容易混淆,A220较A207更具竞争力,但A220难度技术复杂,失误率较大。运用Qualisys红外光点高速运动捕捉系统,深层次剖析A220与A207每个动作阶段的运动学特征。研究结果表明:1)以背阔肌为主导的肩关节稳定性是提臀类和分切类难度动作推起腾空的基础。2)分切类难度肩关节高度高于髋关节,左右髋关节角度变化差异较提臀类难度动作更大。3)A207与A220两个动作总体用时无显著性差异,身体重心Z轴位移变化趋势无明显差异。4)腾起高度是运动员高质量完成提臀类与分切类难度动作的基本条件。  相似文献   

竞技健美操难度动作C289不同技术特征的运动学分析     

张晓莹  刘莉  赵轩立 《北京体育大学学报》2017,40(10):99-105

摘要：竞技健美操成套动作中高难度动作的完成质量是决定比赛胜负的关键。C289作为具备高、难、险技术特征的难度动作，是运动员比赛中获得高分和竞争奖牌的重要因素，在近年的世界大赛中备受青睐，因此如何提升动作质量，避免扣分点，成为当前亟需解决的训练难题。世界优秀运动员的技术模式是极具价值的模型，本研究运用QUALISYS红外光点高速运动捕捉系统，对2名男子世界冠军完成竞技健美操难度动作C289的不同技术特征进行运动学分析，深入研究其动作原理和关键技术，为难度动作的训练提供参考借鉴，有效促进难度动作的价值提升和创新发展。研究表明：1）2名运动员技术要点不同，起跳阶段麻东髋关节缓冲角度与蹬离速度均大于胡邦达，弹性势能储备更多，蹬离地面收腿，易完成转体与屈体动作，但规范性欠缺。2）胡邦达近乎垂直起跳，转体360°后屈髋的风险性更强，腾空时间较麻东少0.05s，动作清晰流畅；屈体时刻2种技术髋关节角度均小于60°，但麻东后仰幅度大，空中屈体形态位置不标准。3）麻东落地点前后与左右方向重心位移变化较大，胡邦达落地相对准确，可控性较强，其腾空上升阶段垂直方向变化较大4）先转体后屈髋技术难度较大，其动作形式特点更符合规则发展导向。  相似文献   

Increasing hip and knee flexion during a drop-jump task reduces tibiofemoral shear and compressive forces: implications for ACL injury prevention training     

Liang-Ching Tsai  Yi-An Ko  Kyle E. Hammond  John W. Xerogeanes  Gordon L. Warren  Christopher M. Powers 《Journal of sports sciences》2017,35(24):2405-2411

Although most ACL injury prevention programmes encourage greater hip and knee flexion during landing, it remains unknown how this technique influences tibiofemoral joint forces. We examined whether a landing strategy utilising greater hip and knee flexion decreases tibiofemoral anterior shear and compression. Twelve healthy women (25.9 ± 3.5 years) performed a drop-jump task before and after a training session (10–15 min) that emphasised greater hip and knee flexion. Peak tibiofemoral anterior shear and compressive forces were calculated using an electromyography (EMG)-driven knee model that incorporated joint kinematics, EMG and participant-specific muscle volumes and patella tendon orientation measured using magnetic resonance imaging (MRI). Participants demonstrated a decrease in peak anterior tibial shear forces (11.1 ± 3.3 vs. 9.6 ± 2.7 N · kg^?1; P = 0.008) and peak tibiofemoral compressive forces (68.4 ± 7.6 vs. 62.0 ± 5.5 N · kg^?1; P = 0.015) post-training. The decreased peak anterior tibial shear was accompanied by a decrease in the quadriceps anterior shear force, while the decreased peak compressive force was accompanied by decreased ground reaction force and hamstring forces. Our data provide justification for injury prevention programmes that encourage greater hip and knee flexion during landing to reduce tibiofemoral joint loading.  相似文献   

Kinematic analysis of the drag flick in field hockey     

Rony Ibrahim  Gert S. Faber  Jaap H. van Dieën 《Sports biomechanics / International Society of Biomechanics in Sports》2017,16(1):45-57

Attaining high speed of the stick head and consequently of the ball is essential for successful performance of the drag flick in field hockey, but the coordination pattern used to maximise stick head speed is unknown. The kinematics of the drag flick was studied in ten elite hockey players who performed twenty shots each towards a target located 1.5 m high. A 150 Hz active marker motion analysis system was used, alongside two force plates to detect foot touchdown. Angular velocity and contribution to stick endpoint speed of upper body joints were analysed. Repeated measures ANOVA was used to compare timing of onset and peak angular velocities between joints. Participants used a kinematic pattern that was close to a proximal-to-distal sequence. Trunk axial rotation and lateral rotation towards the target, right wrist flexion and left wrist extension were the main contributors to stick endpoint speed. Coaches should emphasise trunk rotations and wrist flexion and extension movements for maximising stick head speed. Given the high level of the participants in this study, the coordination of joints motions, as reported here, can serve as a guideline for drag flick training.  相似文献   

Biomechanical characteristics of adults walking forward and backward in water at different stride frequencies     

Cristina Cadenas-Sánchez  Raúl Arellano  Sonia Taladriz  Gracia López-Contreras 《Journal of sports sciences》2016,34(3):224-231

The aim of this study was to examine spatiotemporal characteristics and joint angles during forward and backward walking in water at low and high stride frequency. Eight healthy adults (22.1 ± 1.1 years) walked forward and backward underwater at low (50 pulses) and high frequency (80 pulses) at the xiphoid process level with arms crossed at the chest. The main differences observed were that the participants presented a greater speed (0.58 vs. 0.85 m/s) and more asymmetry of the step length (1.24 vs. 1.48) at high frequency whilst the stride and step length (0.84 vs. 0.7 m and 0.43 vs. 0.35 m, respectively) were lower compared to low frequency (P < 0.05). Support phase duration was higher at forward walking than backward walking (61.2 vs. 59.0%). At initial contact, we showed that during forward walking, the ankle and hip presented more flexion than during backward walking (ankle: 84.0 vs. 91.8º and hip: 22.8 vs. 8.0º; P < 0.001). At final stance, the knee and hip were more flexed at low frequency than at high frequency (knee: 150.0 vs. 157.0º and hip: ?12.2 vs. –14.5º; P < 0.001). The knee angle showed more flexion at forward walking (134.0º) than backward walking (173.1º) (P < 0.001). In conclusion, these results show how forward and backward walking in water at different frequencies differ and contribute to a better understanding of this activity in training and rehabilitation.  相似文献