Optimal release conditions for the free throw in men's basketball

Abstract

The purpose of this study was to determine the optimum release conditions for the free throw in men's basketball. The study used hundreds of thousands of three-dimensional simulations of basketball trajectories. Five release variables were studied: release height, release speed, launch angle, side angle, and back spin. The free throw shooter was assumed to shoot at 70% and to release the ball 2.134 m (7 ft) above the ground. We found that the shooter should place up to 3 Hz of back spin on the ball, should aim the ball towards the back of the ring, and should launch the ball at 52° to the horizontal. We also found that it is desirable to release the ball as high above the ground as possible, as long as this does not adversely affect the player's launch consistency.     

Dynamics of the basketball shot with application to the free throw

Abstract

A completely general three-dimensional dynamic model is presented for the motion of basketball shots that may contact the rim, the backboard, the bridge between the rim and board, and possibly the board and the bridge simultaneously. Non-linear ordinary differential equations with six degrees of freedom describe the ball angular velocity and ball centre position. The model includes radial ball compliance and damping and contains five sub-models: purely gravitational flight, and ball – rim, ball – bridge, ball – board, and ball – bridge – board contact. Each contact sub-model has both slipping and non-slipping motions. Switching between the sub-models depends on the reaction force at, and velocity of, the contact point. Although the model can be used to study shots from any point on the court, we here use it to study the sets of free throw release angle, velocity, angular velocity, and lateral deviation angle that result in success (capture), as well as underhand free throws and those using an under-inflated ball. Free throw shots with larger backspin, lower inflation pressures, and underhand release conditions are shown to result in larger capture percentages.     

Dynamics of the basketball shot with application to the free throw

A completely general three-dimensional dynamic model is presented for the motion of basketball shots that may contact the rim, the backboard, the bridge between the rim and board, and possibly the board and the bridge simultaneously. Non-linear ordinary differential equations with six degrees of freedom describe the ball angular velocity and ball centre position. The model includes radial ball compliance and damping and contains five sub-models: purely gravitational flight, and ball-rim, ball-bridge, ball-board, and ball-bridge-board contact. Each contact sub-model has both slipping and non-slipping motions. Switching between the sub-models depends on the reaction force at, and velocity of, the contact point. Although the model can be used to study shots from any point on the court, we here use it to study the sets of free throw release angle, velocity, angular velocity, and lateral deviation angle that result in success (capture), as well as underhand free throws and those using an under-inflated ball. Free throw shots with larger backspin, lower inflation pressures, and underhand release conditions are shown to result in larger capture percentages.     

上肢力量训练对篮球专项班男生罚球命中率的影响

运用教学实验和比较分析等方法，对上肢力量训练影响篮球罚球命中率进行了研究。结果表明，上肢力量训练对大学专项班学生的罚球命中率有显著性影响，在其他教学条件完全相同的情况下，进行上肢力量训练的学生要比不进行上肢力量训练的学生投篮命中率高得多。     

Especial skill vs. quiet eye duration in basketball free throw: Evidence for the inhibition of competing task solutions

Abstract

The quiet eye (QE) is a gaze phenomenon that has been studied over more than two decades. However, the underlying mechanisms of the well-known expertise effect, namely, longer QE durations in experts when compared to less-skilled athletes remain unclear. Therefore, from a functional perspective, an inhibition hypothesis was proposed that explains long QE durations in experts with increased inhibition requirements over movement parametrisation. This hypothesis was tested by making use of the especial-skill effect in basketball free throw which refers to the observation of higher actual performance than would be predicted on the basis of performance at the nearby locations. In line with the expectations, from the distance of the free-throw line, higher actual than predicted shooting accuracy and longer actual than predicted QE duration were revealed. This suggests that when performing free throws prolonged QE durations are required to shield the optimal against alternative task solutions within the very dense sub-space of this especial skill. These findings suggest an inhibition function of long QE durations in expert athletes.     

Exploring the effects of substituting basketball players in high-level teams

Substituting basketball players during competition is a key process to optimise collective performance. Available research on this topic is scarce, probably due to the difficulty in isolating these effects; thus, the aim of this study was to identify the temporal effects of substitutions in basketball (Spanish professional basketball league). The sample was composed of 1118 substitutions gathered from 21 basketball games. The analysed variables were coach-controlled (player and team’s personal fouls, player in and player out roles, player’s in and out minutes on-court and timeout situation); on-court (foul committed, free throws, 2- and 3-point field-goal effectiveness) and situational variables (scoreline, quality of opposition, game location and game quarter). The results showed positive scoring performances after the substitution for all the analyses. During the first quarter, there were significant effects for fouls committed, scoreline and game location after the substitution. The player’s out personal fouls, free-throw effectiveness, player in, minutes on-court player in, timeout situation and 3-point field-goal effectiveness were significant during the second quarter. The team’s personal fouls, game location, and scoreline were identified as important in the third quarter. The fourth quarter did not show significant effects on the independent variables. Current findings allow optimising coaches’ plans and team management of on-court and bench players throughout the game.     

The physiological load imposed on basketball players during competition

In this study, the intensities of activity and movement patterns during men's basketball were investigated by videoing the movements and monitoring the heart rate and blood lactate responses of eight elite players during competition. The results are expressed according to ‘live time’, which is actual playing time, and ‘total time’, which includes live time as well as all stoppages in play. The mean (± s.d.) frequency of all activities was 997 ± 183, with a change in movement category every 2.0 s. A mean total of 105 ± 52 high‐intensity runs (mean duration 1.7 s) was recorded for each game, resulting in one high‐intensity run every 21 s during live time. Sixty percent of live time was spent engaged in low‐intensity activity, while 15% was spent in high‐intensity activity. The mean heart rate (HR) during live time was 169 ± 9 beats min^‐l (89 ± 2% peak HR attained during laboratory testing); 75% of live time was spent with a HR response of greater than 85% peak HR. The mean blood lactate concentration was 6.8 ± 2.8 mM, indicating the involvement of glycolysis in the energy demands of basketball. It is concluded that the physiological requirements of men's basketball are high, placing considerable demands on the cardiovascular and metabolic capacities of players.     

Effect of verbal instructions and image size on visual search strategies in basketball free throw shooting

We assessed the effects on basketball free throw performance of two types of verbal directions with an external attentional focus. Novices ( n = 16) were pre-tested on free throw performance and assigned to two groups of similar ability ( n = 8 in each). Both groups received verbal instructions with an external focus on either movement dynamics (movement form) or movement effects (e.g. ball trajectory relative to basket). The participants also observed a skilled model performing the task on either a small or large screen monitor, to ascertain the effects of visual presentation mode on task performance. After observation of six videotaped trials, all participants were given a post-test. Visual search patterns were monitored during observation and cross-referenced with performance on the pre- and post-test. Group effects were noted for verbal instructions and image size on visual search strategies and free throw performance. The 'movement effects' group saw a significant improvement in outcome scores between the pre-test and post-test. These results supported evidence that this group spent more viewing time on information outside the body than the 'movement dynamics' group. Image size affected both groups equally with more fixations of shorter duration when viewing the small screen. The results support the benefits of instructions when observing a model with an external focus on movement effects, not dynamics.     

Associations of object control motor skill proficiency,game play competence,physical activity and cardiorespiratory fitness among primary school children

This study investigated if object control relates to children’s game play competence, and examined these competencies as correlates of physical activity and cardiorespiratory fitness. Game play (Game Performance Assessment Instrument), object control (The Test Gross Motor Development-3), moderate-to-vigorous physical activity (Accelerometry), and cardiorespiratory fitness (20-metre shuttle) assessments were completed for 107 children (57% Female, 43% Male) aged 9–12 years (M 10.53, SD 0.65). Two-level regression of object control on game play competence, and object control and game play competence on physical activity and cardiorespiratory fitness assessed associations. Object control competence was positively associated with game play competence (Std. B = 0.25, t (104.77) = 2.38, p = 0.001). Game play competence (Std. B = 0.33, t (99.81) = 5.21, p < 0.000) was more strongly associated with moderate-to-vigorous physical activity than object control competence (Std. B = 0.20, t (106.93) = 2.96, p = 0.003). Likewise, game competence (Std. B = 0.39, t (104.41) = 4.36, p < 0.000) was more strongly associated with cardiorespiratory fitness than object control competence (Std. B = 0.22, t (106.69) = 2.63, p = 0.002). Object control and game competence are both important as correlates of physical activity and cardiorespiratory fitness in children.     

Ball possession effectiveness in men's and women's elite basketball according to situational variables in different game periods

Abstract

The aim of the present study was to identify the importance of basketball performance indicators in predicting the effectiveness of ball possessions in men's and women's basketball, when controlling for situational variables and game periods. The sample consisted of 7234 ball possessions, corresponding to 40 games from the Spanish professional leagues. The effects of the predictor variables on successful ball possessions according to game period were analysed using binary logistic regressions. Results from men's teams show interactions with number of passes and ending player during the first five minutes, with starting and ending zone, defensive systems, screens used and possession duration during the middle thirty minutes, and there were interactions with passes used, possession duration and players involved during the last five minutes. Results from women's teams show interactions with starting and ending zone, passes used, defensive systems and ending player during the first five minutes, and with starting and ending zone, and screens used during the middle thirty minutes. The results show no interaction with situational variables in men's basketball, while league stage was important during the middle thirty minutes and last five minutes in women's basketball, whereas match status was only important during the last five minutes.     

Perception-action coupling in complex game play: Exploring the quiet eye in contested basketball jump shots

The duration of the final fixation before movement initiation – a gaze strategy labelled quiet eye – has been found to explain differences in motor expertise and performance in precision tasks. To date, research only addressed this phenomenon in situations without adversarial constraints. In the present study, we compared the quiet-eye behaviour of intermediately-skilled and highly-skilled basketball players in defended vs. undefended game situations. We predicted differences in quiet-eye duration as a function of skill and performance particularly resulting from late quiet-eye offsets. Results indicated performance-enhancing effects of long quiet-eye durations in the defended but not in the undefended game situation. Furthermore, in line with our prediction, later quiet-eye offsets were associated with superior performance elucidating the phenomenon’s relevance in online-demanding motor tasks. Further, earlier quiet-eye onsets were linked to successful performance supporting earlier suggestions that it is not only the duration but also the timing that matters. These findings not only extend the positive effects of the quiet eye in motor performance to dynamic game-play situations but also support the role of the quiet eye in response to programming and information processing respectively.     

运动员运动表现的影响因素--运动竞赛的挑战性与运动员技能水平对运动员运动表现的影响

随着“文化强国,体育强国”的口号喊起,足以显示国家对体育运动的重视。时值中国建国七十周年的激动时刻,中国女排也成为了大家关注的重点,就在2019年9月29日女排以11胜0负的战绩夺得了女排世界杯的冠军。对于“女排精神”郎平说:女排精神不是赢得冠军,而是有时候知道不会赢,也竭尽全力。这句话就引发了在运动竞赛过程中,竞赛的挑战性和运动员技能水平对运动员的运动表现有什么影响。本研究运用文献资料法、问卷调查法、数理统计法等对50名足球社团的学生进行研究。结果表明:运动竞赛的高挑战性和运动员的高技能水平更有利于运动员运动表现的发挥。     

篮球、蹦床运动员在辨别任务中的返回抑制时程特征

采用辨别任务形式比较运动员与普通大学生的返回抑制时程特征.实验为"3×2×3"的混合设计,组间变量为被试组别(篮球运动员、蹦床运动员和普通大学生各16人),组内变量依次为靶子位置(线索化位置和非线索化位置)和线索化开始到靶子出现的时间间隔(SOA,400、600、800 ms).结果发现:篮球运动员、蹦床运动员和普通大学生分别在SOA为400、800和600 ms开始出现返回抑制.说明与普通大学生相比,篮球运动员表现出较强的抑制效应,能在较短的SOA中出现返回抑制,而蹦床运动员没有表现出返回抑制能力的优势,需要在更长的SOA中才能出现返回抑制.返回抑制对篮球运动员的心理选材和训练监控、定向具有一定的参考价值.     

On the temporal and behavioural consistency of pre-performance routines: An intra-individual analysis of elite basketball players' free throw shooting accuracy

Abstract

The effectiveness of pre-performance routines on skilled performance in a self-paced skill has yet to be verified. In this study, we examine the importance of temporal and behavioural consistency in these routines. The duration and specific pattern of behaviours exhibited before each free throw (n = 284) were observed during 14 National Basketball Association play-off games. An intra-individual standardized score was calculated for each shot's duration. Each player's dominant behavioural routine was identified and each shot was classified as “sequence followed” or “sequence not followed”. No difference was observed in the success rates of shots associated with brief, long, and regular duration routines (P > 0.05). However, players were more successful when they followed their dominant behavioural sequence (83.77% success) than when they deviated from their specific behavioural pattern (71.43% success) (P < 0.05). The findings are interpreted in light of relevant theory and implications for practice are discussed.     

On the temporal and behavioural consistency of pre-performance routines: an intra-individual analysis of elite basketball players' free throw shooting accuracy

The effectiveness of pre-performance routines on skilled performance in a self-paced skill has yet to be verified. In this study, we examine the importance of temporal and behavioural consistency in these routines. The duration and specific pattern of behaviours exhibited before each free throw (n = 284) were observed during 14 National Basketball Association play-off games. An intra-individual standardized score was calculated for each shot's duration. Each player's dominant behavioural routine was identified and each shot was classified as "sequence followed" or "sequence not followed". No difference was observed in the success rates of shots associated with brief, long, and regular duration routines (P > 0.05). However, players were more successful when they followed their dominant behavioural sequence (83.77% success) than when they deviated from their specific behavioural pattern (71.43% success) (P < 0.05). The findings are interpreted in light of relevant theory and implications for practice are discussed.     

Influence of force-vector and force application plyometric training in young elite basketball players

Plyometric training composed by unilateral exercises with horizontal jumping direction seems to be an effective way to improve physical performance in athletes. The present study aimed to compare the influence of a combined jumping direction and force application (horizontal-unilateral vs. vertical-bilateral) plyometric training on linear sprinting, jumping, change of direction (COD) and dynamic balance in young elite basketball players. Twenty young (U-13 to U-14) male basketball players (age: 13.2?±?0.7 years, body mass: 59.5?±?12.7?kg, height: 172.9?±?7.9?cm) were randomly assigned either to a unilateral-horizontal (UH, n?=?10) or bilateral-vertical (BV, n?=?10) plyometric group, twice a week for 6-wk. Both groups performed between 60 and 100 jumps/session. UH executed all jumps unilaterally with horizontal direction, while jumps in the BV were bilaterally with vertical direction. Performance was assessed by a linear sprinting test, vertical and horizontal jumping tests, COD tests (V-cut and 5+5?m with a 180°COD test), an ankle dorsiflexion test and dynamic balance tests (anterior and postero-lateral directions). Within-group differences showed substantial improvements (Effect size (ES):0.31–1.01) in unilateral vertical and horizontal jumping, V-cut test and postero-lateral direction with right leg after both training interventions. Furthermore, UH group also substantially improved (ES:0.33–0.78) all sprinting times and postero-lateral direction with left leg, while BV enhanced anterior direction with left leg (ES:0.25). Between-group analyses showed substantially greater improvements (ES:0.33) in 10-m and V-cut test in UH than in BV. The likely beneficial effect (small ES) achieved in sprinting abilities suggests the combination of unilateral-horizontal jumps to improve such abilities.     

Jump higher,run faster: effects of diversified sport participation on talent identification and selection in youth basketball

ABSTRACT

The aims of this study were to examine the medium-term effects of previous experiences during early stages of sport development on physical capacities of under-13 (U-13) talented basketball players and, to identify variables that discriminated under-14 (U-14) national team training camp selection. Anthropometrical and physical measurements were collected during a basketball training camp. Previous sport experiences (6–10 years), maturity offset, power outputs for jumping and sprinting were determined. A cluster analysis was used to allocate the subjects according to their different levels of sport experiences (more specialized vs. less specialized) to allow creating a dummy variable for the subsequent analysis of the physical variables. A stepwise discriminant analysis was computed to identify the construct that best classifies selected and non-selected players for U-14 national team training camp. The less specialized group outscored more specialized in all physical parameters, irrespectively of gender. The Abalakov Jump Peak Power and Predicted Adult Height (PAH) could successfully discriminate selected from non-selected players for U-14 national team training camp in boys and PAHin girls. The diversified and non-specific sport stimulus during early ages seem to be determinant to the acquisition and development of fundamental movement skills of talented basketball players.     

论篮球运动员的基本功

通过研究篮球运动基本功的含义和作用,阐述了基本功对篮球运动员的重要性,并提出训练运动员基本功的方法和手段,为各级教练员提供参考.     

Physical and perceptual-cognitive demands of top-class refereeing in association football

The aim of this study was to examine the physical and perceptual-cognitive demands imposed on UEFA top-class referees and assistant referees during the final round of the Euro 2000 Championship. To investigate the physical workload, the heart rates during matches were monitored by short-range radio telemetry and translated to different workloads expressed as a percentage of maximal heart rate. For measurement of the perceptual-cognitive workload, video-recordings of games were used to obtain the average number of observable decisions taken by a referee. On average, referees and assistant referees performed the matches at 85±5% and 77±7% of their maximal heart rate, respectively. Over the 31 games, the mean number of observable decisions was 137 (range 104–162), 64% of which were based on communication with the assistant referees and/or the fourth official. To optimize the physical preparation of top-class match officials, the results of this study support the application of intensive and intermittent training sessions, which should place priority on high-intensity aerobic stimuli. In addition, video training is discussed as an additional method for improving match officials' decision making.     

心率监测在高校体育训练中的应用刍议

在当今信息时代的影响下,同时在高校扩招而就业竞争日趋激烈的环境下,高校学生的运动量明显减少,为数不多的体育活动和体育训练就成为学生们有效进行运动锻炼的必然选择.而究竟如何针对不同体质的学生进行不同的训练手段就成为教练或老师的难题,心率监测由于功效显著而倍获高校体育老师的青睐.本文对此进行探讨,旨在使心率监测技术在高校体育训练中得到广泛应用.