Using Principal Components Analysis to Identify Individual Differences in Vertical Jump Performance

Purpose: The purpose of this study was to determine the reliability of cardiorespiratory and pelvic kinematic responses to simulated horseback riding (SHBR) and to characterize responses to SHBR relative to walking in apparently healthy children. Method: Fifteen healthy children (M_age = 9.5 ± 2.6 years) completed SHBR on a commercially available simulator at low intensity (0.27 Hz) and high intensity (0.65 Hz) during 3 sessions on different occasions. Heart rate (HR), blood pressure, and respiratory gases were measured at rest and during steady-state exercise at both intensities. Pelvic displacement was measured during steady-state exercise. Rate of energy expenditure, mean arterial pressure, and rate pressure product (RPP) were calculated. Participants also walked on a treadmill for 26.8 m/min to 80.5 m/min in 13.4-m/min increments at 0% grade during 1 session to compare cardiorespiratory responses with those of SHBR. Results: Physiological variables across all 3 SHBR sessions were similar at both intensities (p>.05 for all). Intraclass correlation coefficients (ICCs) and coefficients of variation indicate good to modest reliability of cardiorespiratory measures during SHBR (ICCs = .542–.996 for oxygen consumption, energy expenditure, and RPP). Cardiorespiratory variables, except for HR, were 2% to 19% greater, and pelvic displacement was up to 37% greater with high-intensity riding. Treadmill walking at all speeds elicited greater physiological responses compared with SHBR (p < .05). Conclusion: Cardiorespiratory responses and pelvic kinematics are reproducible with SHBR in young children, and these responses were lower than those elicited by slow treadmill walking.     

Validity of the Blast Athletic Performance Monitor for Assessing Vertical Jump Height in Female Volleyball Players

Introduction: Wearable activity monitors have been developed for jump height assessment, but the Blast Athletic Performance monitor has not yet been validated, and it remains unclear if the Blast can track changes across a sports season. Methods: Collegiate women’s volleyball players (n = 20) wore the Blast monitor (waistband) while performing standing vertical jumps (SVJs) and one-step vertical jumps (OSJs) weekly during and after a 9-week season. Jump heights from the Blast were compared to a Vertec (criterion). Results: Correlations of Blast and Vertec were moderately high (r = 0.67–0.69), but the Blast underestimated SVJ and OSJ (9.2–10.0 cm), with mean absolute percent errors 19.8–21.0%. A + 23% correction factor reduced errors to 10.5–11.3%. The Blast did not detect small decreases (2–4 cm) in criterion-measured jump height in the postseason. Conclusion: The Blast underestimated jump height and had limited ability to detect changes of up to 5.0 cm following a volleyball season. A relative correction lowered, but did not eliminate, measurement error.     

激活后增强效应的间歇时间对下蹲跳高度影响的Meta分析

目的：探究激活后增强效应（PAP）间歇时间对下蹲跳高度影响。方法：检索PubMed等数据库,查找相关随机对照试验,检索时间从建库至2017年11月30日。按纳入与排除标准筛选文献、提取数据和评价纳入文献研究方法质量后,采用Review Manager 5.3软件进行Meta分析。结果：共纳入15篇文献286名受试者。Meta分析结果显示：间歇时间为0~3 min[MD=-1.46,95% CI（-2.15,-0.78）,P<0.000 1],实验组优于对照组;间歇时间为4~7 min[MD=1.90,95% CI（0.81,2.99）,P=0.000 6]和8~12 min[MD=1.46,95% CI（0.78,2.15）,P<0.000 1],对照组优于实验组;间歇时间为13 min以上[MD=-0.45,95% CI（-2.26,1.36）,P=0.62],对照组与实验组间的差异无统计学意义。敏感性分析提示：改变研究质量差异、纳入标准、统计模型以及效应量的选择等,发现合并结果改变不明显,且受异质性影响的可能较小。结论：诱导方式为杠铃深蹲,诱导强度在85%~93% 1RM之间,重复次数为5~10次,可诱导产生PAP。间歇时间为0~3 min,可以明显提高受试者下蹲跳高度,间歇时间为4~7 min和8~12 min时下蹲跳高度未能显著增加,间歇时间为13min以上时,仍需更多高质量随机对照试验进一步研究证实。在制定诱导PAP方案时,还需考虑诱导对象的年龄与性别、训练经历和力量水平对PAP的影响。     

男子篮球运动员纵跳摸高高度与跳跃素质相关关系的研究

纵跳摸高能力是优秀篮球运动员比赛争抢板球和原地起跳投篮的重要专项素质之一,纵向摸高素质的提高与多种跳跃素质(如助跑摸高、五级蛙跳、连续快速起跳等)可能具有密切的相关关系(假说)。男子篮球运动员纵向摸高素质与跳跃素质的相关关系和科学训练的研究是很有必要的。文章以山西省体育职业学院20名男子篮球专项学生为研究对象,运用测试法测出:原地纵跳摸高、助跑摸高、立定跳远、30秒单摇跳绳、五级蛙跳、立定三级跳各项数据并得出相应的研究结果,以期为相关研究提供参考。     

The Effect of Initial Knee Angle on Concentric-Only Squat Jump Performance

Purpose: There is uncertainty as to which knee angle during a squat jump (SJ) produces maximal jump performance. Importantly, understanding this information will aid in determining appropriate ratios for assessment and monitoring of the explosive characteristics of athletes. Method: This study compared SJ performance across different knee angles—90º, 100º, 110º, 120º, 130º, and a self-selected depth—for jump height and other kinetic characteristics. For comparison between SJ and an unconstrained dynamic movement, participants also performed a countermovement jump from a self-selected depth. Thirteen participants (M_age = 25.4 ± 3.5 years, M_height = 1.8 ± 0.06 m, M_weight = 79.8 ± 9.5 kg) were recruited and tested for their SJ performance. Results: In the SJ, maximal jump height (35.4 ± 4.6 cm) was produced using a self-selected knee angle (98.7 ± 11.2°). Differences between 90°, 100°, and self-selected knee angles for jump height were trivial (ES ± 90% CL = 90°–100° 0.23 ± 0.12, 90°–SS ?0.04 ± 0.12, 100°–SS ?0.27 ± 0.20; 0.5–2.4 cm) and not statistically different. Differences between all other knee angles for jump height ranged from 3.8 ± 2.0 cm (mean ± 90% CL) to 16.6 ± 2.2 cm. A similar outcome to jump height was observed for velocity, force relative to body weight, and impulse for the assessed knee angles. Conclusions: For young physically active adult men, the use of a self-selected depth in the SJ results in optimal performance and has only a trivial difference to a constrained knee angle of either 90° or 100°.     

Three Different Methods of Calculating Vertical Jump Height from Force Platform Data in Men and Women

The purpose of the present study was to investigate the effects of different methods to calculate vertical jump height in men and women. Fifty men and 50 women performed three countermovement vertical jumps for maximal height on a force platform, the highest of which was used in the statistical analyses. The peak displacement attained by the center of mass (COM) during flight was obtained from three different calculations: (1) using the time in the air (TIA), (2) using the vertical velocity of the COM at take-off (TOV), and (3) adding the positive vertical displacement of the COM prior to take-off to the height calculated using TOV (TOV+s). With all calculations, men produced significantly greater jump heights than women (p < 0.05). TIA produced significantly greater jump heights than TOV in men and women, while TOV+s produced significantly greater jump heights than both TIA and TOV in men and women (p < 0.05). Despite these differences, the methods produced consistent results for both men and women. All calculation methods have logical validity, depending upon the definition of jump height used. Therefore, the method used to calculate jump height should be determined by the equipment available to the practitioner while giving consideration to the sources of error inherent in each method. Based upon the present findings, when using a force platform to calculate vertical jump height, practitioners are encouraged to use the TOV method.     

不同膝角静态蹲跳的生物力学研究

运用三维测力系统,对不同膝角静态蹲跳的测试结果进行比较分析：着重讨论了最大力值、蹬伸时间、冲量值等主要生物力学指标的变化规律及其对纵跳高度的影响。     

浅析影响跳远助跑准确性的因素及改进措施

当代跳远技术对助跑提出的要求很高 ,不仅距离长、速度高 ,而且对助跑技术的结构及准确性的要求也很高。助跑是跳远的前提 ,没有准确的助跑 ,跳远技术再好 ,也没有成绩 ,助跑的准确性已是当前跳远运动发展的一个趋势 ,是运动员取得优异成绩的保证 ,分析影响准确性的因素 ,为提高准确性提出了训练方法。     

三级跳远技术教法设计的理论与实践

文章从教学顺序、方法、手段3个层面建构了三级跳远普修课教法设计的理论模型,并对其进行了实证研究.结果表明:"逆向叠加教学顺序"、"结构-定向"教学方法、与教学重点与难点相匹配的练习手段三者有机组合的三级跳远教法效果达到了预期实验设计目的.     

Evaluation of Four Vertical Jump Tests: Methodology,Reliability, Validity,and Accuracy

Vertical jump performance tests can give considerably different results, even when different methods are used to analyze the same jump trial from the same subject. To evaluate and compare 4 different methods commonly used to measure vertical jump performance, 52 physically active men each performed 5 maximal vertical jumps. Kinetic and kinematic data were used to analyze each trial using the 4 methods: a criterion test based on body center of mass displacement (VJPT), 2 methods based on vertical takeoff velocity as calculated from the force platform, and 1 method based on time in the air (JUMPAIR). All 4 methods showed excellent reliability (R > .97). Using VJPT as the criterion, the other 3 methods showed excellent coefficients of validity (R > .95) but poor accuracy: The obtained vertical jump height scores were statistically different among all methods (p < .01). JUMPAIR is considered a relatively simple and inexpensive method to obtain valid and reliable measures of vertical jump performance without an arm swing, provided the appropriate adjustments are made to the jump results.     

The Effect of Depth Jumps and Weight Training on Leg Strength and Vertical Jump

Abstract

In recent years, a method of plyometrics (exercises that cause a rapid lengthening of a muscle prior to contraction) called depth jumping has become a part of the training routine of many athletes. Two experiments are described in which the effectiveness of the exercises is examined. In Experiment 1, undergraduate students in beginning weight training classes trained with three different jumping programs: (1) maximum vertical jumps, (2) 0.3 m depth jumps, and (3) 0.75 m and 1.10 m depth jumps. In addition, all groups also lifted weights. In Experiment 2, a weight training class and the volleyball team at Brigham Young University-Hawaii were divided into two groups. One group lifted weights and performed 0.75 and 1.10 m depth jumps. The other group only lifted weights. In Experiment 1, the three training programs resulted in increases in one repetition maximum (1 RM) squat strength, isometric knee extension strength, and in vertical jump; however, there were no significant differences between treatments. In Experiment 2, all groups made significant increases in vertical jump, except the group of weight lifters, who did no jumping. It was concluded that depth jumps are effective but not more effective than a regular jumping routine.     

关于提高跳远运动员助跑准确性的研究

对7名跳远运动员采用标记跑进行了6个月的助跑训练,结果表明,这种方法能够促使助跑最后几步步长的稳定,明显提高助跑的准确性。并且有利于加快运动员助跑最后几步的步频,提高助跑后10m的水平速度,从而导致跳远专项成绩的提高。     

运动性疲劳对纵跳动力学特征的影响

为揭示下肢运动性疲劳对纵跳的动力学特征的影响,22名男性体育教育专业大学生志愿参加了实验。结果表明,随着下肢负荷时间的增加纵跳的垂直方向分力和冲量下降,而左右、前后方向分力和冲量增加,三个方向的力矩随负荷时间的延长而增加。     

肌肉离心收缩的后激活增强效应对纵跳能力的影响

目的：探讨不同离心负荷激活干预对后激活增强效应所产生的影响及有效作用时间。方法：通过对14名普通男性大学生运用肌肉离心收缩激活方式,观察后续纵跳表现的影响。结果：在激活干预后即刻,对照组与离心负荷（105%1RM和125%1RM）激活干预两个实验组纵跳峰值功率和纵跳的高度没有显著差异,激活干预两个组之间的纵跳表现没有显著差异。激活干预的两组在T3和T6时段的纵跳功率峰值均明显高于对照组。在T3时段两个激活干预实验组纵跳高度峰值明显高于对照组,在T6时段,105%1RM激活干预组的纵跳高度明显增加。结论：纵跳测试前加入大强度的离心负荷刺激会小幅度提高纵跳的能力,不同强度离心负荷的激活干预的后激活增强效应差异性不大,采用105%1RM强度的离心负荷激活干预在 3~6 min有明显的后激活增强效应。     

我国女子三级跳远技术发展现状及对策

针对我国女子三级跳远运动技术水平的现状,采用文献资料法,专家访谈法,问卷法,就我国女子三级跳远运动员同世界优秀运动员在速度,三级如何衔接,及三跳比例方面进行对比分析。提出应更新训练理念,提高专项训练水平;进一步完善女子三级跳远速度、力量、跳跃能力方面训练的内容和手段,是我国女子三级跳远运动水平提高的重要保证。     

Do the peak and mean force methods of assessing vertical jump force asymmetry agree?

Abstract

The aim of this study was to assess agreement between peak and mean force methods of quantifying force asymmetry during the countermovement jump (CMJ). Forty-five men performed four CMJ with each foot on one of two force plates recording at 1,000 Hz. Peak and mean were obtained from both sides during the braking and propulsion phases. The dominant side was obtained for the braking and propulsion phase as the side with the largest peak or mean force and agreement was assessed using percentage agreement and the kappa coefficient. Braking phase peak and mean force methods demonstrated a percentage agreement of 84% and a kappa value of 0.67 (95% confidence limits: 0.45–0.90), indicating substantial agreement. Propulsion phase peak and mean force methods demonstrated a percentage agreement of 87% and a kappa value of 0.72 (95% confidence limits: 0.51–0.93), indicating substantial agreement. While agreement was substantial, side-to-side differences were not reflected equally when peak and mean force methods of assessing CMJ asymmetry were used. These methods should not be used interchangeably, but rather a combined approach should be used where practitioners consider both peak and mean force to obtain the fullest picture of athlete asymmetry.     

递增负重蹲跳与提踵时小腿三头肌表面肌电图信号比较

目的:通过对男大学生小腿三头肌在递增负重提踵和蹲跳动作时表面肌电(sEMG)信号的分析,探讨动作形式与神经肌肉活动方式之间的联系。方法:男大学生在不负重和30%、60%、80%、100%最大力量(1RM)负重下分别进行一次提踵和蹲跳动作,同时记录腓肠肌内侧头(GM)、外侧头(GL)和比目鱼肌(SO)向心收缩阶段的sEMG信号,比较各等级负重条件下两种动作运动时iEMG、MF和MPF等肌电指标的变化。结果:在进行负重提踵时,随着重量增加,GM、GL和SO表面肌电的iEMG均显著增加,但MF和MPF在不同负重等级完成动作时的差异不显著;在进行负重蹲跳时,各肌肉表面肌电信号的iEMG、MF和MPF在各级负重之间具有显著差异,其数值与重量的增加具有线性关系;在不负重提踵时各肌肉的iEMG值与蹲跳差异不显著,但大负重后显著高于蹲跳;MF和MPF值在不负重提踵时显著高于蹲跳,负重后其差异基本不显著。结论:在递增负重提踵和蹲跳动作时,小腿三头肌向心收缩阶段的sEMG信号表现存在差异,其所反映的神经肌肉控制方式不同,提示所完成动作的动力学特性如速度、多关节链等,可能会影响运动单位募集的方式。     

The Effect of In-Season Traditional and Explosive Resistance Training Programs on Strength,Jump Height,and Speed in Recreational Soccer Players

Purpose: Resistance training is often performed in a traditional training style using deliberate relatively longer repetition durations or in an explosive training style using maximal intended velocities and relatively shorter repetition durations. Both improve strength, “power” (impulsivity), and speed. This study compared explosive and traditional training over a 6-week intervention in 30 healthy young adult male recreational soccer players. Method: Full body supervised resistance training was performed 2 times a week using 3 sets of each exercise at 80% of one repetition maximum to momentary failure. Outcomes were Smith machine squat 1 repetition maximum, 10 meter sprint time, and countermovement jump. Results: Both groups significantly improved all outcomes based on 95% confidence intervals not crossing zero. There were no between-group differences for squat 1 RM (TRAD = 6.3[5.1 to 7.6] kg, EXP = 5.2[3.9 to 6.4] kg) or 10 meter sprint (TRAD = ?0.05[?0.07 to ?0.04] s, EXP = ?0.05[?0.06 to ?0.03] s). Explosive group had a significantly greater increase in countermovement jump compared to the traditional group (TRAD = 0.7[0.3 to 1.1] cm, EXP = 1.3[0.9 to 1.7] cm). Conclusion: Both the traditional training and explosive training performed to momentary failure produced significant improvements in strength, speed, and jump performance. Strength gains are similar independent of intended movement speed. However, speed and jump performance changes are marginal with resistance training.     

男子三级跳远专项力量训练与弱爆发力特征的关系

通过对速度和爆发力素质差的三级跳远运动员高春冬采用特定的训练方案进行训练,使其专项成绩1a内提高0．8m,达到15．40m(国家一级运动员)的水平。特定的训练方案是以提高快速跳跃力量、发展退让肌群力量和专项耐力为目标,以不同的手段组合成4套训练方案,其针对性强,效果好。该方案适用于相近水平的三级跳远运动员。     

跳高、跳远之间运动技能和运动素质迁移的研究

运用文献资料、对比、理论分析等方法,就跳高与跳远之间运动技能、运动素质的迁移规律进行了研究,结果表明两个项目之间存在着许多相互迁移的共同要素,且跳远对跳高的积极性迁移更为明显;同时也分析了两个项目之间在某些技术细节上存在差异而产生一定干扰;指出,运用迁移原理,加强跳远训练是提高跳高成绩的有效途径。