原地连续纵跳的运动生物力学特征研究

为研究原地连续纵跳的运动生物力学特征,运用录像拍摄与三维测力同步测试的方法对其研究发现,不同频率作用下的时间参数存在一定差异,随着纵跳频率的增加,时间参数都表现出逐渐减小的趋贽.同一频率作用下随着运动时间的延长,支撑时间逐渐增人.蹬伸力峰值随着连续纵跳运动时间的延长呈现明显逐渐减小的趋势,不同频率原地连续纵跳蹬伸力峰值对起跳效果的影响程度是不同的;缓冲冲量和蹬伸冲量随运动时间的延长,也都呈现出明显的逐渐减小的趋势,并且运动前期的恢复系数人于1.     

北京世锦赛女子跳远运动员起跳技术运动学分析

运用文献资料、信息技术、数理统计等方法,以北京世界田径锦标赛女子跳远决赛前三名运动员为研究对象,对跳远起跳技术进行运动学分析.结果表明:北京世锦赛女子跳远运动员的起跳技术整体上已达到世界优秀水平,在起跳阶段蹬地角度、起跳扇面角度比较理想;在起跳中时间大体呈现T1> T2=T3 的特征,存在较大的不合理性;运动员起跳腿的"缓冲与蹬伸"和摆动腿的"蹬、摆"技术呈现出摆动腿摆动不积极、蹬伸质量不高的特征.     

Which drop jump technique is most effective at enhancing countermovement jump ability, “countermovement” drop jump or “bounce” drop jump?

Abstract

The drop jump is a popular form of plyometric exercise often undertaken to enhance countermovement jump ability (jump height). Despite its popularity the effects of drop jump training on countermovement jump height are often inconsistent. Such inconsistencies may be as a result of differences in the drop jump technique being employed. Two recognised forms of drop jump are the “countermovement” drop jump and the “bounce” drop jump and the current study examined the effects of eight weeks of training with these drop jump techniques on countermovement jump height. Methods: A kinetic and kinematic analysis of each participant's countermovement jump, bounce- and countermovement drop jumps was undertaken prior to training. Participants were then randomly assigned to a bounce drop jump training group (n = 34), a countermovement drop jump training group (n = 35) or a control group (n = 34). Changes in jump height were examined following training. Results: The countermovement drop jump training group increased their countermovement jump height by 2.9 cm (6%), which was a significant change (P < 0.05) in comparison to that experienced by the bounce drop jump (-0.2 cm, -0.4%) and the control group (-0.1 cm, 0.2%). Conclusion: The countermovement drop jump may be more effective than the bounce drop jump at enhancing countermovement jump height.     

我国优秀女子跳远运动员起跳技术的运动学分析

为了找出目前我国女子跳远运动员技术存在的问题,为其动作技术训练提供一定的理论依据和数据参考。运用文献资料法、三维录像解析法和数理统计法,对我国优秀女子跳远运动员起跳动作进行三维录像解析分析。研究得出:八名运动员的着地角均偏小,不利于快速起跳动作的完成;郑艳、陈水清和邹畅三名运动员的蹬地角均偏小;除陆敏佳和许小令外,其余六名运动员起跳扇面角偏大,降低了起跳效率。八名运动员起跳腿部力量偏弱以及抵抗冲击力的能力差,导致缓冲效果不理想;八名运动员都较好的控制了腾起角度,但绝对速度偏小使我国女子跳远运动员的腾起初速度与优秀运动员之间的差距加大。     

Acute effects of a cluster-set protocol on hormonal,metabolic and performance measures in resistance-trained males

Abstract

Limited research exists on rest-pause or cluster-set (CS) protocols. Acute effects of a traditional set (TS) and CS protocols of resistance exercise on serum growth hormone (GH), cortisol (C), blood lactate (BL), countermovement vertical jump (CMVJ) and standing long jump (SLJ) were compared. Eleven resistance-trained males (22.9±2.6 year; 176.9±10.6 cm; 78.5±1.6 kg; 12.9±3.1% BF) completed one repetition maximum tests for clean pull (CP), back squat (BS) and bench press (BP). Subjects were then randomly assigned to TS or CS protocols for sessions 2 and 3, and performed CP and BS lifts followed by two circuits of three sets of three exercises. GH, C, BL, CMVJ and SLJ were measured pre-exercise (Pre), mid-exercise following completion of CS or TS protocol (Mid), immediately (IP), 15 (15P) and 30 (30P) minutes post-exercise. Repeated measures ANOVAs examined differences in GH, C, BL, CMVJ and SLJ. No differences (p>0.05) existed between protocols for GH and C. GH levels 15P were elevated (p<0.05) above 30P (15.78 + 4.66 vs. 12.10 + 4.66 µg^.L^?1). C levels 30P were elevated (p<0.05) above Pre (716.85 + 102.56 vs. 524.79 + 75.79 nmol^.L^?1). Interaction (p <0.05) existed between protocol and time for BL; mid-BL was lower for CS than TS (7.69±3.73 vs. 12.78±1.90 mmol^.L^?1). Pooled data for CMVJ and SLJ were greater (p <0.05) across the CS protocol. The less metabolically taxing CS protocol resulted in better sustainability of jump measures.     

第11届全运会女子三级跳远运动员三跳技术的运动学分析

对参加第11届全运会田径比赛女子三级跳远决赛前8名运动员三跳技术的相关运动学参数进行研究,结果表明:我国女子三级跳远运动员助跑绝对速度和起跳速度利用率较差,只有8.96 m/s和95.5%,与世界女子三级跳运动员的9.41 m/s和98.2%相比,差异具有显著性(P<0.01);起跳脚着地与离地瞬间身体重心水平速度较差,只有8.71 m/s,与世界选手的9.33 m/s相比,差异有非常显著性(P<0.01);单足跳与跨步跳时的身体重心腾起角度适宜,分别为(17.19±4.37)°、(15.07±4.12)°,但最后跳跃的身体重心腾起角过大(23.57±4.12)°,超过世界运动员的16°~20°;三跳的支撑总时间较长,起跳效果不理想。     

Force– and power–time curve comparison during jumping between strength-matched male and female basketball players

The purpose of this study was to compare force– and power–time curve variables during jumping between Division I strength-matched male and female basketball athletes. Males (n?=?8) and females (n?=?8) were strength matched by testing a one-repetition maximum (1RM) back squat. 1RM back squat values were normalised to body mass in order to demonstrate that strength differences were a function of body mass alone. Subjects performed three countermovement jumps (CMJ) at maximal effort. Absolute and relative force– and power–time curve variables from the CMJs were analysed between males and females. Average force– and power–time curves were generated for all subjects. Jump height was significantly greater (p?≤?.05) in males than females. Absolute force was higher in males during the concentric phase, but not significantly different (p?≥?.05) when normalised to body mass. Significance was found in absolute concentric impulse between sexes, but not when analysed relative to body mass. Rate of force development, rate of power development, relative peak force, and work were not significantly different between sexes. Males had significantly greater impulse during the eccentric phase as well as peak power (PP) during the concentric phase of the CMJ than did females in both absolute and relative terms. It is concluded that sex differences are not a determining factor in measured force during a CMJ when normalised to body mass between strength-matched subjects. However, eccentric phase impulse and concentric phase PP appear to be influenced by sex differences independent of matching strength levels.     

国内外优秀男子跳远选手全程技术运动学特征比较研究

运用文献资料法和对比分析法,以国内外23名优秀男子跳远选手为研究对象,利用运动学参数对其全程技术特征进行比较分析,结果表明:国内选手助跑最后2步着板与离板瞬时水平速度、最后2步的步频提高率、垂直速度与腾起角均低于国外选手,而助跑的速度利用率、最后2步的步长变化、离地瞬间身体重心水平速度损失之和则明显高于国外选手.     

外加束缚在连续下蹲跳至力竭过程中对下肢肌肉活动的影响

目的：运用表面肌电技术探讨外加紧身束缚在连续下蹲跳至力竭过程中对下肢主要发力肌肉活动的影响及其可能的内在机制.方法：随机抽取成年健康男性受试者12名,利用梯度压缩式紧身运动长裤使下肢分别在4种不同紧身束缚压下完成全力连续下蹲跳至力竭运动测试;对一侧下肢肌群均方根肌电图（RMS）和中心品频率（CF）肌电指标作信号处理后,采用单因素方差分析进行实验数据的统计和比较.结果：（1）无外加紧身束缚时,下肢肌RMS整体随蹲跳次数的增加呈现出先增大后减小的趋势,CF仅在疲劳后期有一定程度的降低;（2）外加轻度紧身束缚对下肢肌RMS及CF的整体变化特征无显著影响;（3）外加中度紧身束缚在疲劳末期使下肢肌RMS减小幅度降低,CF的降低趋势及程度减弱;（4）外加高度紧身束缚在疲劳末期使下肢肌RMS减小幅度上升,CF的降低程度增加.结论：连续下蹲跳至力竭过程中,外加轻度紧身束缚对下肢肌肉活动无明显影响;外加中度紧身束缚有利于维持力竭前肌力的输出功率和动作电位的传导速率,对下肢肌肉疲劳后期的活动有积极影响;而外加高度紧身束缚则在一定程度上会加速下肢肌肉疲劳后期的力竭进程.     

Influence of football match time–motion parameters on recovery time course of muscle damage and jump ability

ABSTRACT

We analysed the time course of recovery of creatine kinase (CK) and countermovement jump (CMJ) parameters after a football match, and correlations between changes in these variables and match time–motion parameters (GPS-accelerometry) in 15 U-19 elite male players. Plasma CK and CMJ height (CMJ_H), average concentric force (CMJ_CON) and average eccentric force (CMJ_ECC) were assessed 2 h before and 30 min, 24 h and 48 h post-match. There were substantially higher CK levels 30 min, 24 h and 48 h (ES: 0.43, 0.62, 0.40, respectively), post-match. CMJ_ECC (ES: ?0.38), CMJ_H (ES: ?0.35) decreased 30 min post, CMJ_CON (ES: ?0.35), CMJ_ECC (ES: ?0.35) and CMJ_H (ES: ?1.35) decreased 24 h post, and CMJ_CON (ES: ?0.41) and CMJ_H (ES: ?0.53) decreased 48 h post. We found correlations between distance covered at velocities ≤21 km · h^?1 and changes in CK at 24 h (r = 0.56) and at 48 h (r = 0.54) and correlations between CK and distance covered >14 km · h^?1 (r = 0.50), accelerations (r = 0.48), and decelerations (r = 0.58) at 48 h. Changes in CMJ_CON 30 min and 24 h post (both r = ?0.68) correlated with impacts >7.1·G. Decelerations >2 m · s^?2 correlated with changes CMJ_CON (r = ?0.49) at 48 h and CMJ_ECC (r = ?0.47) at 30 min. Our results suggest that match GPS-accelerometry parameters may predict muscle damage and changes in components of neuromuscular performance immediately and 24–48 h post-match.     

我国优秀男子跳远和三级跳远运动员助跑最后一步运动学参数的比较

跳远和三级跳远均属于典型的速度力量型远度项目。采用文献资料、专家访谈、测试法和数理统计等研究方法,通过对我国优秀男子跳远和三级跳远运动员的助跑最后一步的某些运动学参数进行对比研究,结果表明:(1)助跑最后一步摆动腿支撑阶段的身体重心高度变化值,跳远组比三级跳远组大且具有显著性差异。(2)助跑最后一步的最大缓冲瞬间,跳远组的摆动腿大腿角速度比三级跳远组大,且具有显著性差异。(3)助跑最后一步支撑阶段摆动腿缓冲扇角和蹬伸扇角,三级跳远组均大于跳远组。     

竞技武术C级跳跃难度的运动学特征研究

采用运动生物力学的研究方法,分析和讨论了武术C级跳跃难度的运动学特征及动作特点,发现腾空摆莲720°成功率最低,选择人数最少。旋子转体的成功率高,但完成的人并不多,主要是该动作的结构容易导致运动损伤。建议在跳跃难度的训练中可以通过提高动作旋转速度达到规则要求的旋转角度。研究还发现,部分C级跳跃难度动作的分值设置不科学。     

Scaling isometric mid-thigh pull maximum strength in division I Athletes: are we meeting the assumptions?

ABSTRACT

This study examined the validity of various scaling methods, isometric mid-thigh pull (IMTP) peak force using various scaling methods, and the relationships between IMTP peak force and countermovement jump height. Fifty-one collegiate baseball and soccer athletes performed two maximal IMTPs. Absolute peak force was compared between teams and when data were scaled using ratio (RS), traditional allometric (ALLO_Trad), and fitted allometric (ALLO_Fit) scaling. ALLO_Trad and ALLO_Fit validity was violated because different derived exponents existed for baseball (b = 0.20) and soccer (b = 1.20). Soccer athletes produced greater RS peak force compared to baseball (p = 0.012), while no difference existed with absolute, ALLO_Trad or ALLO_Fit (all p > 0.05) peak force. Moderate relationships existed between body mass and absolute (r = 0.402, p = 0.003) and RS (r = -0.328, p = 0.019) peak force, while trivial relationships existed with ALLO_Trad and ALLO_Fit (both r < -0.10, p > 0.05). Trivial relationships existed between countermovement jump height and absolute, RS, ALLO_Trad, and ALLO_Fit (all r < 0.20, p > 0.05) peak force. The current dataset violated allometric scaling assumptions, making it inappropriate to use ALLO_Trad and ALLO_Fit scaling. Practitioners must understand the assumptions, limitations, and purpose of scaling methods.     

我国优秀男子跳高运动员起跳前摆动腿支撑技术的三维运动学分析

采用两台SONY高速摄像机对当前我国优秀男子跳高运动员起跳前摆动腿支撑技术进行现场同步拍摄，运用爱捷运动录像反馈系统进行解析。结果表明：我国优秀男子跳高运动员在摆动腿着地瞬间，身体重心距摆动腿着地点的水平距离较大，在摆动腿缓冲阶段，部分被试摆动腿膝关节缓冲幅度过大，水平速度的损失较为严重；最后一步步长、步长／身高指数较小，与国外优秀运动员相比有显著性差异。