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1.
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.  相似文献   

2.
ABSTRACT

This study aimed to assess the effect of playing surface (Natural [NT] and Artificial [AT] Turf) on the fatigue response to a soccer-specific exercise protocol (SSEP). Eighteen male soccer players completed the SSEP on NT and AT with pre-, post-, and 48 h post-assessments of eccentric knee flexor (eccKF) and concentric knee extensor peak torque (PT), peak countermovement (CMJ) and squat jump (SJ) height, and Nordic hamstring break angle. No significant main effects for surface or any surface and time interactions were observed for any of the outcome measures, except for eccKF PT recorded at 3.14 rad·s-1, which was significantly lower 48 h post-trial in the AT condition (AT = 146.3 ± 20.4 Nm; NT = 158.8 ± 24.7 Nm). Main effects for time were observed between pre- and post-trial measures for eccKF PT at all angular velocities, Nordic break angle, CMJ and SJ height. Nordic break angle, and both CMJ and SJ height were significantly impaired 48 h post-trial when compared to pre-trial. The findings of the current study suggest surface dependent changes in eccKF PT which may have implications for recovery and subsequent performance after competition on AT.  相似文献   

3.
Abstract

This study aimed to investigate the contributions of kinetic and kinematic parameters to inter-individual variation in countermovement jump (CMJ) performance. Two-dimensional kinematic data and ground reaction forces during a CMJ were recorded for 18 males of varying jumping experience. Ten kinetic and eight kinematic parameters were determined for each performance, describing peak lower-limb joint torques and powers, concentric knee extension rate of torque development and CMJ technique. Participants also completed a series of isometric knee extensions to measure the rate of torque development and peak torque. CMJ height ranged from 0.38 to 0.73 m (mean 0.55 ± 0.09 m). CMJ peak knee power, peak ankle power and take-off shoulder angle explained 74% of this observed variation. CMJ kinematic (58%) and CMJ kinetic (57%) parameters explained a much larger proportion of the jump height variation than the isometric parameters (18%), suggesting that coachable technique factors and the joint kinetics during the jump are important determinants of CMJ performance. Technique, specifically greater ankle plantar-flexion and shoulder flexion at take-off (together explaining 58% of the CMJ height variation), likely influences the extent to which maximal muscle capabilities can be utilised during the jump.  相似文献   

4.
Knee peak torque (PT) is associated to jump performance in volleyball players. It is not clear whether muscle strength imbalances of the knee joint can influence jump performance. The purpose of study was to analyse the association between PT and knee muscular imbalances with jump performance in professional volleyball players. Eleven elite male volleyball players (90.3 ± 9.7 kg body mass and 1.94 ± 0.06 m height) were evaluated in an isokinetic dynamometer at speeds of 60, 180 and 300 deg/s. Muscle strength imbalances were obtained through calculation of contralateral deficit between limbs and the conventional ratio (hamstrings/quadriceps). Countermovement jump (CMJ) was performed on a force plate to calculate mechanical power and height. Association was found between knee extensor PT at 180 deg/s with CMJ power (r = 0.610, p = 0.046). Conventional ratio at 300 deg/s showed negative association with CMJ (r = ?0.656, p = 0.029). The optimal ratio between knee extensors PT in relation to the flexors PT is associated with the greater mechanical power in CMJ. Contralateral deficit does not seem to be associated with the CMJ performance. Considering the knee extensor PT is associated with CMJ power, our findings suggest that strength-based training in volleyball athletes should not omit the conventional muscle ratio.  相似文献   

5.
通过对篮、排球各10名一级运动员膝关节进行等动测试分析,结果表明:两项目运动员膝关节肌力特征最主要差异在于伸肌离心收缩能力和屈肌向心收缩能力,膝关节主对抗肌肌力比和同一肌群的离心与向心峰力矩比率上也存在一定差异,这种差异可能与两项目运动员起跳方式有关。  相似文献   

6.
It is unclear whether weighted vest (WV) use improves countermovement vertical jump (CMVJ) performance by enhancing stretch-shortening cycle (SSC) function via increased storage and utilisation of elastic strain energy. In is also unknown whether WV use stimulates different responses in men and women. WV effects on energy storage and utilisation during CMVJ were examined in men and women. Nine men (25 ± 3 y; 89.7 ± 18.7 kg; 1.8 ± 0.1 m) and 12 women (24 ± 3 y; 62.7 ± 10.3 kg; 1.6 ± 0.1 m) performed CMVJ wearing a WV with (loaded) and without (unloaded) 10% added mass while kinematic and ground reaction force (GRF) data were obtained. A longer eccentric sub-phase and increased storage of elastic strain energy occurred when loaded. Increased positive joint work occurred during the concentric portion of loaded CMVJ. Women exhibited less positive hip work and greater positive ankle work than men during the unloading and eccentric sub-phases, respectively. Joint work was similar between sexes during the concentric sub-phase, likely due to decreased trunk extension excursion in men when loaded. Women and men employ different SSC strategies during the CMVJ, though the different strategies do not alter energy storage or concentric mechanical output.  相似文献   

7.
篮、排球运动员下肢3关节肌等速测试的对比研究   总被引：32，自引：3，他引：29  
虞重干  郭权 《体育科学》2000,20(1):73-75,88
用Cybex等速测力系统对篮排球运动员进行了下肢3关节力量测试,结果表明两项目运动员下肢3关节肌力的主要差别在于膝关节伸肌离心收缩能力和膝关节屈肌向心收缩能力,在运动实践中可能表现为在起跳过程中的缓冲能力的差异。  相似文献   

8.
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   

9.
This study examined the physical differences in adult male basketball players of different competitive level and playing position using a large cohort. In the middle of the regular season, 129 players from four different Divisions completed a Yo-YoIR1 and, after 3-to-8 days, they performed a 6-min continuous running test (Mognoni’s test), a counter-movement jump (CMJ) test and a 5-min High-intensity Intermittent running test (HIT). Magnitude-based inferences revealed that differences in HIT were very likely moderate between Division I and II and likely small between Division II and III. The differences in absolute peak power and force produced during CMJs between Division I and II and between Division II and III were possibly small. Differences in Yo-YoIR1 and Mognoni’s test were very likely-to-almost certain moderate/large between Division III and VI. We observed possibly-to-likely small differences in HIT and Mognoni’s test between guards and forwards and almost certainly moderate differences in absolute peak power and force during CMJs between guards and centres. The ability to sustain high-intensity intermittent efforts (i.e. HIT) and strength/power characteristics can differentiate between competitive level, while strength/power characteristics discriminate guards from forwards/centres. These findings inform practitioners on the development of identification programs and training activities in basketball.  相似文献   

10.
This study investigated the effects on neuromuscular performance of a 6-week Optimal Load Training (OLT) and a novel modified Complex Training (MCT) (complex pairs: the same exercise using a moderate and an OL) in basketball players, in-season. Eighteen male athletes were randomly assigned to one of the protocols. Anthropometric measurements were taken to evaluate body composition. Lower- and upper-body maximum dynamic strength, countermovement jump (CMJ), standing long jump (SLJ), 10-m sprint and change of direction (COD) were also assessed. Moderate-to-large strength gains (presented as percentage change ± 90% confidence limits) were obtained for half-squat (OLT: 10.8 ± 5.3%; MCT: 17.2 ± 11.6%) and hip thrust (OLT: 23.5 ± 17.7%; MCT: 28.2 ± 19.0%). OLT athletes achieved likely small improvements in sprint (1.6 ± 1.6%) and COD (3.0 ± 3.2%). Players in the MCT attained likely moderate improvements in COD (3.0 ± 2.0%) and possibly small in SLJ (2.5 ± 4.6%). No protocol relevantly affected CMJ or body composition. An ANCOVA test revealed unclear between-group differences. In conclusion, both protocols increased basketball players’ strength without the use of heavy loads (> 85% 1RM) and without impairing sprint, CMJ and SLJ performance. These findings suggest that basketball strength and conditioning professionals may use either method to counteract strength losses during the season.  相似文献   

11.
This study examined the kinetic and temporal differences between countermovement jumps (CMJs) and eccentrically loaded CMJs. A survey of 109 coaches and athlete showed that 87% of respondents regularly used jumps with added mass within training. Sixteen male and thirteen female track and field athletes from sprinting, hurdling and jumping events performed 5 bodyweight CMJs 5 jumps wearing a weighted jacket and 5 eccentrically loaded dumbbell (LDB) jumps trials in a randomised order. Peak force (PF), peak power (PP), flight time (FT), concentric time (CON-T), eccentric time (ECT), total time (TIME) and eccentric/concentric ratio (E/C-Ratio) were obtained from force plate data. Statistically significant differences (p < 0.05) with moderate to large magnitude effect sizes were found between men and women in FT, PP and PF but not in any of the temporal variables. The results indicated that the WJ decreased FT in men (↓9%) and women (↓10%) but LDB jumps had similar FT to CMJ. Overall, the results showed that LDB increased the E/C Ratio (↑50% and ↑42%) and decreased CON-T (↓37% and ↓25%) compared with WJ and CMJ respectively. LDB jumping is not recommended as a training modality as it tends to disrupt the relative timing of the jump action.  相似文献   

12.
To investigate the influence of adding a weekly eccentric-overload training (EOT) session in several athletic performance’s tests, 18 team-handball players were assigned either to an EOT (n?=?11) or a Control (n?=?7) group. Both groups continued to perform the same habitual strength training, but the EOT group added one session/week during a 7-week training programme consisting of four sets of eight repetitions for the bilateral half-squat and unilateral lunge exercises. The test battery included handball throwing velocity, maximum dynamic strength (1RM), countermovement jump (CMJ), 20?m sprint, triple hop for distance, and eccentric/concentric power in both the half-squat and lunge exercises. Data were analysed using magnitude-based inferences. Both groups improved their 1RM in the half squat, 20?m sprint time, and CMJ performance to a similar extent, but the EOT group showed a beneficial effect for both right [(42/58/0), possibly positive] and left [(99/1/0), very likely positive] triple hop for distance performance. In addition, the EOT group showed greater power output improvements in both eccentric and concentric phases of the half-squat (difference in percent of change ranging from 6.5% to 22.0%) and lunge exercises (difference in per cent of change ranging from 13.1% to 24.9%). Nevertheless, no group showed changes in handball throwing velocity. Selected variables related to team-handball performance (i.e. functional jumping performance, power output) can be improved by adding a single EOT session per week, highlighting the usefulness of this low-volume/high-intensity training when aiming at optimizing dynamic athletic performance.  相似文献   

13.
周英 《搏击·武术科学》2011,8(11):104-106,117
文章通过对中关篮球运动员身高的比较发现：我国国家男子篮球队运动员的平均身高已经超过了美国国家男篮,但我国CBA篮球运动员的平均身高却低于美国NBA篮球运动员。在二十一世纪五、六十年代,我国篮球运动根据我国篮球运动员的自身条件,在实践中贯彻“快速、灵活、准确”的指导方针。“以小打大”的训练指导思想,是1981年全国篮球工作会议即“杭州会议”认真总结了我国篮球运动三十多年发展的历史经。  相似文献   

14.
本文试图研究在极限负荷斜蹲运动过程中肌肉做离心工作、向心工作和静力工作时的肌电信号特征。结果发现,股外肌做离心工作对的IEMG低于向心工作,而向心工作的IEMG又低于等长工作。根据对肌电信号频率特性的分析结果,股外肌做离心工作时,参与工作的运动单位可能主要是慢肌运动单位,参与工作的运动单位的数目可能少于向心工作和等长工作,等长工作中参与工作的运动单位的数目可能最多。  相似文献   

15.
The aim of this study was to establish the ways in which coping style and situational appraisals are related to the consistency of using approach and avoidance coping strategies for skilled Australian basketball referees (n = 133) after three game-related stressful events. The events, ‘making a mistake’, ‘aggressive reactions by coaches or players’ and ‘presence of important others’, were determined from previous research on sources of acute stress among basketball officials. Our findings indicated that: referees exhibited consistent avoidance, but not approach, coping styles; they used more avoidance than approach strategies; and they perceived stress to be positively correlated with approach, and negatively associated with avoidance, coping strategies. These findings suggest that individual differences exist in perceptions of stress (i.e. situational appraisals), controllability and coping styles among moderately and highly skilled basketball referees. The implications for teaching cognitive and behavioural strategies for effective coping with acute stress in basketball officiating are discussed.  相似文献   

16.
Previous studies analysing electromyograms (EMGs) from indwelling electrodes have indicated that fast-twitch motor units are selectively recruited for low-intensity eccentric contractions. The aim of this study was to compare the frequency content of surface EMGs from quadriceps muscles during eccentric and concentric contractions at various contraction intensities. Electromyograms were recorded from the rectus femoris, vastus lateralis and vastus medialis muscles of 10 men during isokinetic (1.05 rad x s(-1)) eccentric and concentric knee extension contractions at 25%, 50%, 75% and 100% of maximal voluntary contraction (MVC) for each contraction mode. Additionally, isometric contractions (70 degrees) were performed at each intensity. The mean frequency and root mean square (RMS) of the surface EMG were computed. Mean frequency was higher for eccentric than concentric contractions at 25% (P < 0.01), 50% (P < 0.01) and 75% (P < 0.05) but not at 100% MVC. It increased with increasing contraction intensity for isometric (P < 0.001) and concentric (P < 0.01) contractions but not for eccentric contractions (P = 0.27). The EMG amplitude (RMS) increased with increasing contraction intensity similarly in each contraction mode (P < 0.0001). Higher mean frequencies for eccentric than concentric contractions at submaximal contraction intensities is consistent with more fast-twitch motor units being active during eccentric contractions.  相似文献   

17.
篮球后卫运动员专项认知眼动特征研究   总被引：10，自引：1，他引：9  
采用ASL504型眼动仪对后卫位置男子篮球运动员和普通大学生在注视篮球比赛实景图片时的眼动特征进行研究。结果发现,篮球后卫运动员具有较高的专项信息加工效率;在注视篮球比赛实景图片时,篮球后卫运动员较普通大学生具有更为合理的注视分配和注视模式。  相似文献   

18.
我国男子乒乓球运动员个性特征的研究   总被引：4，自引：1，他引：3  
对我国优秀男子乒乓球运动员16项个性因素进行测试，对他们的个性状态作出诊断，并与优秀男篮运动员和男大学生16项个性因素的差异性进行比较。结果表明，我国男子乒乓球运动员16项个性因素具有典型的项目特征和很强的一致性，他们个性特征的总体状态具有乐群聪慧、争强好胜、情绪稳定、勇敢自信、进取创新的特点，同时亦反映其缺乏吃苦耐劳、意志品质较薄弱、有时易冲动的个性特征。我国男子乒乓球运动员与男篮运动员相比，在乐群性、幻想性、怀疑性、忧虑性和紧张性等个性因素存在着显性和非常显性差异，说明男子乒乓球运动员更为乐群随和、沉着自信和情绪稳定。与普通大学生相比，男子乒乓球运动员表现出更为乐群开朗、情绪稳定、冒险敢为、精明能干的个性特征。  相似文献   

19.
ABSTRACT

The purpose of the study was to assess factors that contribute to countermovement jump (CMJ) performance in women’s basketball athletes. Thirteen female athletes participated and were tested for maximal oxygen uptake (VO2max) and heart rate (HRmax). Athletes were monitored, daily for a total of 21 weeks with heart rate-based wearable devices and CMJ performance and body weight were tested weekly after one day of recovery. 3-jump average height (CMJavg), maximum height jump (CMJmax), and CMJ power (Watts) were calculated and recorded. Playing intensities >85% HRmax, HRavg, HRmax and training load were averaged for three consecutive days prior to the recovery day. After the season, data was grouped as changes in CMJ power from week one: Large (≤ ?4.39% change), Moderate (?4.4% to ?0.62% change), and Minimal (≥ ?0.61% change) changes. Fixed-effects models revealed a main effect of group (p ≤ 0.05) for CMJavg, CMJmax, VO2max, weekly percent changes in body weight and for 3-day training load, HRavg, and playing time at >85% HRmax. When athletes experienced minimal changes in CMJ performance, relative to large changes, they produced greater power, jumped higher, avoided negative changes in weekly body weight, had a greater preseason VO2max and 3-day average workloads appeared to have an impact on CMJ performance  相似文献   

20.
中国聋人篮球运动发展现状及对策研究   总被引：1，自引：0，他引：1  
在对我国聋人篮球运动员现状调查中发现,我国聋人篮球运动员的年龄绝大部分都在25岁以下,男子平均身高179．24cm,平均体重71．14kg,女子平均身高167．76cm,平均体重58．74kg,基本完成了九年制义务教育。我国聋人篮球运动员从事篮球的目的都集中在热爱篮球,运动员训练年限男子分布比较平均．女子则集中在一年以下,家人对其参加篮球运动都持支持的态度,我国聋人篮球运动员经济来源主要来自于家庭。此次聋人篮球比赛赛前集训时间集中在1～3个月,队员对于训练环境基本满意。为了发展和提高我国聋人篮球运动,应加强省市级的聋人篮球基础工作,建立建全省市聋人篮球的梯队建设,加大投入,使得我国聋人篮球运动更快地发展。  相似文献   

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