田径、举重运动员下肢反应力量能力探析     

郑念军 《山东体育学院学报》2005,21(3):1-5,9

采用国际上通用的反应力量测试手段和方法，对191名田径、举重运动员和普通人进行了实验测试，通过对测试结果的统计分析，发现：（1）田径、举重运动员下肢反应力量测试结果未能表现出运动项目和竞技水平间的显著性差异；（2）跳深实验中，适宜的下落高度随着性别、运动项目、竞技水平等条件的不同，差异较大，因此，判定适宜的下落高度时，最好具体分析，因人而异；（3）起跳时间对于判定适宜的下落高度也有一定影响，准确的适宜下落高度的判定，对于反应力量的训练具有重要意义。  相似文献   

过早大强度专业化力量训练对足球运动员下肢形态影响的研究     

李振斌  李宏强 《安徽体育科技》2006,27(2):34-36

探讨过早大强度专业化力量训练是否对足球运动员下肢形态存在影响,从而科学地进行足球训练。方法:对原陕西省足球队二级以上的运动员25名与体育院系足球学生25名以及普通高校学生25名的下肢形态的相关指标进行对比。实验结果显示:体育院系学生与普通高校学生的下肢形态没有明显差异(P>0.05);原陕西省足球队与普通高校学生有明显差异(p<0.001),足球队运动员的腿部接近于“O”型以及脚尖略微内扣。结论:过早大强度专业化力量足球训练会对运动员下肢形态存在消极的影响。  相似文献   

4周下肢间歇负压干预对优秀赛艇运动员心率变异性和儿茶酚胺的影响     

董徽徽  高炳宏 《上海体育学院学报》2020,(4):78-83

目的探讨下肢间歇负压干预对赛艇运动员心率变异性(HRV)相关指标和儿茶酚胺的影响。方法将国家赛艇队的14名运动员分为试验组和对照组,试验组运动员每周用间歇负压干预5 d,持续4周,对照组无其他干预方式。试验期间均对2组运动员进行HRV相关指标和儿茶酚胺的测试。结果试验前2组运动员各指标均无统计学差异。开始干预后2组的变化如下:①在时域指标中,试验组正常窦性R-R间期标准差(SDNN)在第3周时高于对照组(P<0.05)。②在频域指标中,试验组高频(HF)值在第2周和第3周时高于对照组(P<0.05),而其高频与低频比(LF/HF)在第1、3和4周时低于对照组(P<0.05)。③2组儿茶酚胺组内、组间比较均无统计学差异,但试验组儿茶酚胺下降程度比对照组高。结论4周的间歇负压干预对运动员自主神经系统功能的恢复有明显促进作用,对儿茶酚胺的分泌也具有抑制趋势;这有利于降低运动员心脏负荷,促进运动后的生理恢复。  相似文献   

Comparing the magnitude and direction of asymmetry during the squat,countermovement and drop jump tests in elite youth female soccer players     

Chris Bishop  Lucas A. Pereira  Valter P. Reis  Paul Read  Anthony N. Turner  Irineu Loturco 《Journal of sports sciences》2020,38(11-12):1296-1303

ABSTRACT

The aims of the present study were to provide an in-depth comparison of inter-limb asymmetry and determine how consistently asymmetry favours the same limb during different vertical jump tests. Eighteen elite female under-17 soccer players conducted unilateral squat jumps (SJ), countermovement jumps (CMJ) and drop jumps (DJ) on a portable force platform, with jump height, peak force, concentric impulse and peak power as common metrics across tests. For the magnitude of asymmetry, concentric impulse was significantly greater during the SJ test compared to CMJ (p = 0.019) and DJ (p = 0.003). No other significant differences in magnitude were present. For the direction of asymmetry, Kappa coefficients revealed fair to substantial levels of agreement between the SJ and CMJ (Kappa = 0.35 to 0.61) tests, but only slight to fair levels of agreement between the SJ and DJ (Kappa = ?0.26 to 0.18) and CMJ and DJ (Kappa = ?0.13 to 0.26) tests. These results highlight that the mean asymmetry value may be a poor indicator of true variability of between-limb differences in healthy athletes. The direction of asymmetry may provide a useful monitoring tool for practitioners in healthy athletes, when no obvious between-limb deficit exists.  相似文献   

Key somatic variables associated with,and differences between the 4 swimming strokes     

Alan M. Nevill  Yassine Negra  Tony D. Myers  Senda Sammoud  Helmi Chaabene 《Journal of sports sciences》2020,38(7):787-794

ABSTRACT

This study identified key somatic and demographic characteristics that benefit all swimmers and, at the same time, identified further characteristics that benefit only specific swimming strokes. Three hundred sixty-three competitive-level swimmers (male [n = 202]; female [n = 161]) participated in the study. We adopted a multiplicative, allometric regression model to identify the key characteristics associated with 100 m swimming speeds (controlling for age). The model was refined using backward elimination. Characteristics that benefited some but not all strokes were identified by introducing stroke-by-predictor variable interactions. The regression analysis revealed 7 “common” characteristics that benefited all swimmers suggesting that all swimmers benefit from having less body fat, broad shoulders and hips, a greater arm span (but shorter lower arms) and greater forearm girths with smaller relaxed arm girths. The 4 stroke-specific characteristics reveal that backstroke swimmers benefit from longer backs, a finding that can be likened to boats with longer hulls also travel faster through the water. Other stroke-by-predictor variable interactions (taken together) identified that butterfly swimmers are characterized by greater muscularity in the lower legs. These results highlight the importance of considering somatic and demographic characteristics of young swimmers for talent identification purposes (i.e., to ensure that swimmers realize their most appropriate strokes).  相似文献   

复合式训练影响青少年下肢爆发力的meta分析     

翟华楠  周彤 《武汉体育学院学报》2020,54(10):65-71

目的：运用元分析的方法检验复合式训练对青少年下肢爆发力影响的干预效果，检验并提出最优的运动干预方案。方法：运用STATA 15.1和Review Manager 5.3对纳入的10篇文献和301名被试者通过设置抗阻类型、抗阻强度、间歇时间、训练频率和训练周期等5个调节变量进行亚组分析，采用固定效应模型进行整体效应、异质性、发表偏倚性检验。结果：（1）复合式训练对跳跃类运动表现的影响效应量d0.36，对短跑类运动表现的影响效应量d-0.51，两者达到中等效应且具有统计学意义；（2）本研究纳入的10篇文献异质性较低，间歇时间、训练频率和训练周期的对跳跃类和短跑类运动表现影响的效应量有一定差别。结论：（1）复合式训练能够显著提升青少年跳跃类和短跑类运动表现；（2）抗阻训练选择等张收缩、强度70%1RM以下、小于3分钟的间歇时间、在4~8周内选择每周1-2次的复合式训练能够对青少年运动表现有较好的提升；（3）围绕青少年人群开展的复合式训练较为缺乏，后续研究应加强理论与实践研究。  相似文献   

The effect of limb dominance on lower limb functional performance – a systematic review     

Timothy M. McGrath  Gordon Waddington  Jennie M. Scarvell  Nick B. Ball  Rob Creer  Kevin Woods 《Journal of sports sciences》2016,34(4):289-302

Lower limb dominance (or lateral preference) could potentially effect functional performance. Clinicians are often asked to make judgements as to when a patient has sufficiently “recovered” from an injury, typically using strength and dynamic performance outcome measures. The primary purpose of this study was to systematically review the literature in relation to limb dominance within active adult populations and discuss some limitations to current methods and relate this to current clinical practice. A search of MEDLINE and CINAHL and EMBASE databases and reference lists of those articles identified was performed. Eleven articles were selected for meta-analysis. There was no statistical effect of limb dominance for any of the functional tests: isokinetic quadriceps and hamstring tests, hamstring:quadriceps ratios, single-leg hop for distance, single-leg vertical jump and vertical ground reaction force following a single-leg vertical jump. Pooled symmetry values varied from 94.6% to 99.6% across the tests, above the clinically accepted benchmark of 90% used in clinical practice. Although the results of this study must be used with discretion, asymmetries in the tasks described in this analysis should be viewed as undesirable and remedied accordingly. Further research is needed to quantify asymmetries, particularly in relation to sport-specific contexts.  相似文献   

Assessment of three-dimensional joint kinematics of the upper limb during simulated swimming using wearable inertial-magnetic measurement units     

Silvia Fantozzi  Andrea Giovanardi  Fabrício Anício Magalhães  Rocco Di Michele  Matteo Cortesi  Giorgio Gatta 《Journal of sports sciences》2016,34(11):1073-1080

The analysis of the joint kinematics during swimming plays a fundamental role both in sports conditioning and in clinical contexts. Contrary to the traditional video analysis, wearable inertial-magnetic measurements units (IMMUs) allow to analyse both the underwater and aerial phases of the swimming stroke over the whole length of the swimming pool. Furthermore, the rapid calibration and short data processing required by IMMUs provide coaches and athletes with an immediate feedback on swimming kinematics during training. This study aimed to develop a protocol to assess the three-dimensional kinematics of the upper limbs during swimming using IMMUs. Kinematics were evaluated during simulated dry-land swimming trials performed in the laboratory by eight swimmers. A stereo-photogrammetric system was used as the gold standard. The results showed high coefficient of multiple correlation (CMC) values, with median (first–third quartile) of 0.97 (0.93–0.95) and 0.99 (0.97–0.99) for simulated front-crawl and breaststroke, respectively. Furthermore, the joint angles were estimated with an accuracy increasing from distal to proximal joints, with wrist indices showing median CMC values always higher than 0.90. The present findings represent an important step towards the practical use of technology based on IMMUs for the kinematic analysis of swimming in applied contexts.  相似文献   

The influence of shoe drop on the kinematics and kinetics of children tennis players     

Alexis Herbaut  Pascale Chavet  Maxime Roux  Nils Guéguen  Christophe Gillet  Franck Barbier 《European Journal of Sport Science》2016,16(8):1121-1129

This study investigated the immediate effects of reducing the shoe drop (i.e. the difference between the heel and the forefoot height) on the kinematics and kinetics of the lower extremities of children tennis players performing a tennis-specific movement. Thirteen children tennis players performed a series of simulated open stance forehands wearing 3 pairs of shoes differing only in the drop: 0 (D0), 6 (D6) and the control condition of 12?mm (D12). Two embedded forceplates and a motion capture system were used to analyse the ground reaction forces and ankle and knee joint angles and moments of the leading lower limb. In D6 compared with D12, the peak impact force was reduced by 24% (p?=?.004) and the ankle was less dorsiflexed at foot strike (p?=?.037). In D0 compared with D12, the peak impact force was reduced by 17% (p?=?.049), the ankle was less dorsiflexed at foot strike (p?=?.045) and the knee was more flexed at foot strike (p?=?.007). In addition, 4 out of 13 participants (31%) presented a forefoot strike pattern for some of the trials in D0. No difference was observed across shoe conditions for the peak knee extensor moment (p?=?.658) or the peak ankle plantarflexor moment (p?=?.071). The results provide preliminary data supporting the hypothesis that for children tennis players, using a 6-mm lower shoe drop might reduce heel impact forces and thus limit potentially impact-related injuries.  相似文献   

两性关系中的权力归属     

刘勇 《邵阳学院学报(社会科学版)》2002,(Z2)

现行的社会秩序体现了男性的意志、男性社会的意识形态特征。这种特征由性别地位、性别角色和性别气质构成。它们分别属于政治范畴 ,社会范畴 ,心理范畴 ,三者之间相互依赖 ,形成三体相连而又相互独立的独联体。男性认为女性是他者 ,他者的存在是威胁和危险。于是男性必须排除这种威胁和危险  相似文献