A review on the basketball jump shot

The ability to shoot an effective jump shot in the sport of basketball is critical to a player's success. In an attempt to better understand the aspects related to expert performance, researchers have investigated successful free throws and jump shots of various basketball players and identified movement variables that contribute to their success. The purpose of this study was to complete a systematic review of the scientific literature on the basketball free throw and jump shot for the purpose of revealing the critical components of shooting that coaches, teachers, and players should focus on when teaching, learning, practising, and performing a jump shot. The results of this review are presented in three sections: (a) variables that affect ball trajectory, (b) phases of the jump shot, and (c) additional variables that influence shooting.     

Control of locomotion in expert gymnasts in the absence of vision

The main aim of this study was to determine how gymnasts are affected by the removal of vision when executing simple moves. A secondary aim was to establish whether crucial sensory cues exist for blindfolded gymnasts. Eight expert gymnasts were asked to maintain a straight displacement during three types of blindfolded locomotion: walking, steering a wheelchair and verbally ordering a second person pushing their wheelchair. In the first two conditions,active displacement made proprioceptive cues available to update the body trajectory. In the last condition, however, proprioceptive cues were greatly reduced, since the gymnasts displaced passively. The performance of the gymnasts was compared to that of eight experts in other non-gymnastic sports (control group). The results showed that the participants veered in all conditions. However, except in the verbal condition, the gymnasts departed less from linearity than the controls. We conclude that: (1) even for a simple motor task, gymnasts' performance is altered by eliminating vision; (2) compared with other sportsmen and women, gymnasts are better able to deal with the absence of vision when proprioceptive cues are available. These findings suggest two possible explanations: (1) gymnasts are more able to ‘pick up' crucial information and (2) a gymnast's proprioceptive system is more sensitive.     

Predicting Future Trends in Adult Fitness Using the Delphi Approach

Abstract

This study determined how experts see the future of adult fitness by using the Delphi Technique as a measurement tool. Experts (n = 50), all Fellows of the American College of Sports Medicine, were selected on the basis of their reputations in adult fitness. Three questionnaires were submitted to the panel. In the first questionnaire each expert listed five or more events, trends, or developments they thought would take place and five or more events they would like to see take place in the next 25 years. From the events and trends listed on this questionnaire, 100 items were generated that formed the basis for the last two questionnaires. Responses to the items on the second questionnaire were evaluated on a 5-point Likert scale for probability and desirability. In the third questionnaire, group means and standard deviations were calculated and recorded for each item. Only those items which were significantly (p < .01) higher than 3.0, the average probability or desirability response on the Likert scale, were included in the analysis. The items were divided into seven categories: fitness in sport and recreation, fitness and wellness, fitness in industry, fitness in education, fitness in business, research in fitness, and fitness equipment and facilities. The highest single mean for any item for both probability (M = 4.31) and desirability (M = 4.83) was increased awareness of health and fitness among the elderly.     

Comparison of Hydrostatic Weighing at Residual Volume and Total Lung Capacity in Children

Abstract

The influence of perceptions of the motivational climate and perceived ability on situational motivation and the physical activity behavior of 213 male and 229 female adolescent physical education students (M age= 12.56 years; SD = 0.96) was examined over a 3-day period. A significant age by gender interaction emerged, with physical activity declining from the sixth to eighth grade. The decline was more pronounced among female than male students. Perceptions of a mastery climate were strongly related to more self-determined forms of situational motivation. In contrast, perceptions of a performance climate were strongly related to less self-determined forms of situational motivation. Results of a hierarchical regression analysis revealed gender, perceived ability, and perceptions of a mastery climate to explain a significant amount of variance in physical activity. These findings suggest that promoting a mastery oriented motivational climate in physical education will foster self-determined situational motivation and physical activity.     

Cardiac Structure and Function in Women Basketball Athletes: Seasonal Variation and Comparisons with Nonathletic Controls

Abstract

To characterize hypertrophy and quantify seasonal changes in cardiac structure and function of women collegiate basketball (BB) athletes (n = 15), echocardiography (echo) measurements were made in the fall (FALL₁), winter (WIN), and spring (SPR), then again during the subsequent fall (FALL₂; n = 10). Comparisons were made to age-matched nonathletes (NA) measured during FALL₁ (n = 22) and SPR (n = 5). Left ventricular (LV) internal dimension–diastole (LVIDd), LV end-diastolic volume (LVEDV), stroke volume (SV), LV mass (LVM), septal thickness (IVS), LV posterior wall thickness (LVPW), right ventricular (RV) internal dimension-diastole (RVIDd), and aortic root diameter (AOD) were significantly larger (12–70%) in the athletes; RVIDd-, LVEDV-, SV-, and LVM-index were also significantly greater (8–46%). From FALL₁ to SPR measurement periods, LVWd, RVWd, LVEDV, SV, IVS, and LVM-index increased significantly (7–18%) in the athletes. Over the same period of time, LVIDd, LAD, AOD, LVEDV, and SV measured in the five NA subjects increased significantly. In the athletes, LVIDs, RVIDd, IVS, LVPW, and LVM decreased significantly (5–30%) from the SPR to FALL₂ measurement period. These data characterize the general nature of the cardiac hypertrophy noted in women BB athletes compared to NA controls and show that distinct changes in heart structure corresponding to different periods of the competitive season can occur in these athletes.     

Physiological Responses to Maximal Treadmill and Handweighted Exercise

Abstract

The purpose of this investigation was to compare the peak physiological responses among four protocols that employed different amounts of handweighted exercise in 16 males (aged 26.3 ± 4.1 years). The four protocols were (a) uphill treadmill running (UR; 3.36 m-s¹, 2.5% grade increase-3 min¹); (b) uphill treadmill walking while pumping 1.36kg handweights (HW) (UWHW; 1.79ms¹, 5.0% grade increase-3 min¹; (c) treadmill walking while pumping .91-kg HW (WHW; 1.79 m-s¹, 0% grade, .91kg HW increase-3 min¹); and (d) standing in place and pumping HW (SHW; arm work as described in WHW). It was hypothesized that the peak responses would be inversely proportional to the estimated muscle mass activated (i.e., UR = UWHW > WHW > SHW). Dependent variables included peak oxygen uptake (VO₂ peak), peak heart rate (HRpeak), peak ventilation (V_epeak), and peak respiratory exchange ratio (RERpeak). No differences were noted between UR and UWHW with respect to any of the dependent variables. All variables (except RERpeak) were greater (p < .01) in UR and UWHW than either WHW or SHW. RERpeak was greater (p < .01) in UR and UWHW than in WHW. VO₂peak and HRpeak were greater (p < .01) in WHW when compared to SHW. Mean VO₂peak was 97.5, 69.7, and 60% of UR for UWHW, WHW, and SHW, respectively. Therefore, walking and pumping handweights provides a maximal stimulus to the oxygen transport system.     

A mathematical analysis of the 4 × 100 m relay

In this study, we examined aspects of the 4 2 100 m relay that are amenable to mathematical analysis. We looked at factors that affect the time required to complete the relay, focusing on the performance of elite male athletes. Factors over which the individual athletes, and the team coach, can exercise some control are: the starting positions of the runners on legs 2, 3 and 4, the positions at which baton exchanges occur, the free distances at the baton exchanges and the running order of the athletes. The lane draw is shown to have an important influence on the relay time, although it is outside the control of the team coach. Teams drawn in the outside lanes benefit from the inverse relation between bend radius of curvature and running speed. For teams composed of athletes with different times over 100 m, we show that the fastest relay times are achieved with the fastest athlete taking the first leg, with the slowest two runners allocated to the final two legs.     

A Test of Schmidt's Schema Theory of Discrete Motor Skill Learning

Abstract

Schmidt's (1975) schema theory was tested with subjects who had to emit a rapid aiming response while wearing prism glasses. The glasses enabled them to view the target, but not their responding limb or the outcome of the movement. The problem was to determine the effect of (a) training with variable target practice, and (b) experiencing visual displacement information of the target, prior to training, on performance in transfer to a novel target distance. A 2 × 2 (type of practice × displacement information) factorial design was used, in which four groups of 15 male college subjects performed 60 training trials with verbal knowledge of results. The groups with variable target practice had less error on initial transfer to the novel target and throughout transfer than the groups with nonvariable target practice. No evidence was found to indicate that rate of learning for a novel target distance during transfer in the absence of KR is a positive function of the variability of target practice in training. Nor was any effect found for experiencing visual displacement information on performance in transfer.     

Theoretical Analysis of Aggressive Golf Putts

Abstract

The present study examined the relationship between students' perceptions of the motivational climate and beliefs about the causes of success, preference for challenging tasks, and satisfaction in physical education. Responses of 50 female and 46 male students (M age = 12.08 years; SD = .72) showed that perceptions of a mastery-oriented motivational climate were related to the belief that motivation or effort caused success and satisfaction. In contrast, perceptions of a performance climate were related to the belief that deception caused success and related negatively to the students' preference for challenging tasks. Results of hierarchical regression analyses revealed that perceptions of the motivational climate explained a significant amount of unique variance in the students' responses after controlling for dispositional goal orientations. The results suggest that the teacher can influence the salience of a mastery-oriented climate and, in so doing, optimize a child's motivation in physical education.