Jackie Hudson, Scholar

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Basketball Articles: Abstracts and Introductions

In the sport of basketball, the ability to shoot the basketball is a key skill. Though shooting techniques have changed, as Cooper (1990) acknowledges, shooting one handed, with one hand behind the ball and the other to the side, has become the common method of shooting both jump shots and free throws. Since shooting is such an integral part of the game, an ability to shoot successfully from a variety of distances would naturally be desirable. Consequently, identifying the characteristics which skilled performers use to achieve success across different distances should be useful information to coaches, teachers, and players.

The search for the determinants of success is compounded by the nature of shooting which allows for "endless combinations of segmental contributions in conjunction with numerous projection angles and velocities which can result in shots which directly or indirectly fall through the basket" (Hudson, 1982, p. 95). Martin (1981) suggested using a movement analysis approach to describe good shooting skill and advocated the use of kinematic variables. Yates and Holt (1982) examined kinematic characteristics of 10- and 20-foot jump shots but did not report how the 10-foot shot differed from the 20-foot shot. In general, they found that the ball was released while the body was moving upward in a predominantly vertical path and that the body, shoulder, elbow, wrist, and hand all contributed to ball projection.

In two studies of free throw shooting, elite, male basketball players were described in terms of kinematic variables. Hayes (1989) examined ball velocity and the contribution that each body segment made to ball velocity. Within this elite group of subjects there was little variability of the ball velocity at release. He also found that early in the propulsion phase, the lower body was the main contributor; at the end of the propulsion phase, the forearm's contribution increased, and finally, just before release, the hand provided the major contribution. Tsarouchas, Kalamaras, Giavroglou and Prassas (1990) analyzed elite free throw shooters as well. Based on one successful shot from each subject, they concluded that the trajectory of the ball prior to and after release approximated the same linear path. Combining the results of Hayes and Tsarouchas et al., it appears that coordination may be an important element in good shooting.

With shooting, certain characteristics are thought to exist among consistently successful shooters, although individual variation in noncrucial elements is common. For example, Hudson (1985b) compared elite and good free throw shooters and found little variability within elite shooters on the kinematic variables which distinguished skillfulness. There was, however, greater variability on characteristics which were inconclusive predictors of skillfulness. In another study of free throw shooting, Hudson (1985a) examined successful shots relative to unsuccessful shots. Within the elite shooters, there were no trends to separate the made from the missed shots. She concluded that these players were using individual strategies of adjustment and that a case study approach should be employed in future studies of highly skilled shooters. Tsarouchas et al. (1990) also found that there were individual differences within good shooters in that some had a "low" elbow technique while others used a "high" elbow technique in their shooting form.

Although free throw studies provide information about what may be important to success in shooting from 4.6 m, there is limited information about kinematic variables which are associated with success at other distances. Hence, the purpose of this study was to analyze field goals taken from three different distances. Specifically, do kinematic characteristics increase systematically as distance from the goal increases? Further, do more successful shooters differ from less successful shooters in terms of kinematics?

The set shot is used by virtually all basketball players when shooting free throws, but it is especially significant for the small and/or inexperienced performer. The set shot requires less size and strength than the jump shot, so it may be the best method of shooting field goals for small players. Because the set shot is the easiest shot to learn and the foundation for the lay-up and jump shot, it is an important skill for the novice. In fact, time spent practicing the correct mechanics of the free throw should pay off directly in improved free throw shooting and indirectly in better field goal shooting for all players.

Many writers have given what they consider to be the proper mechanics of free throw shooting. The usual models for these descriptions of technique are professional players. While it is generally true that the best players to mimic are the successful ones, professionals may be using individual advantages which are not available to the small (or even average) performer. Perhaps a better idea would be to examine the basic requirements of shooting and then design patterns of movement that suit each individual.

It is unlikely that any two individuals will shoot free throws in exactly the same manner. There are several reasons for this: each individual has unique structural and functional assets and liabilities; there are many patterns of movement and paths of projection that can result in successful shots; and there is latitude for each player to add stylistic interpretations. However, in spite of the inevitability of individual variations, all mechanically sound patterns of shooting should be reproducible and accurate, regardless of the amount of fatigue or stress. The basic characteristics that an ideal pattern should include are: 1) minimal action outside the primary plane, 2) moderate velocity from a minimal number of body segments, 3) smooth integration of body segments, and 4) a projection path with a generous margin for error.

Here are some suggestions for how small shooters can incorporate good mechanics and avoid common problems. Larger players might also profit from reviewing these techniques. (Article in pdf)

This study was designed to examine the use of selected biomechanical variables in the prediction of basketball skill. The subjects were college women in three mutually exclusive groups of basketball skill: an elite group of six competitors on the United States team in the World University Games, a good group of seven players on a varsity team, and a poor group of nine members of an instructional class. An accuracy test and digitized film records provided the data for 12 variables related to the process or product of free throw shooting. Discriminant analysis was employed to predict the categorical variable of skill. The most discrimination came from variables of accuracy, stability, and height of release rather than from variables of projection. Poor shooters were distinguished by instability; elite shooters were characterized by a high point of release and accuracy under pressure. Depending on the method of prediction, rates for correct classification of subjects ranged from 76-100%. Thus, it appears that discriminant analysis using biomechanical variables can be a successful tool in the prediction of basketball skill.

The development of skilled movement patterns depends in part on knowledge about errors in technique. For most performers this knowledge is understood at an intuitive level and acquired through the process of trial and error. Perhaps, the period of skill acquisition could be shortened if the learner had empirically derived information about errors in technique.

One approach to the diagnosis of errors is to examine intraindividual differences in successful and unsuccessful trials using biomechanical variables. Due to the abundance and interrelationship of biomechanical variables, a multivariate statistical method, such as regression analysis, is appropriate. To test the applicability of regression analysis in the diagnosis of biomechanical errors, the basketball free throw was studied.

Free throw shooting in basketball is a task that falls into two broad categories of sports skills. First, it is a task of accuracy. Second, it requires submaximal velocity for most populations of players. Because of the submaximal velocity demands, there are endless combinations of segmental contributions in conjunction with numerous projection angles and velocities which can result in shots which directly or indirectly fall through the basket. In addition to the segmental actions which contribute to shooting performance, there may be other actions which are extraneous to performance. These non-related characteristics can be termed style. Since the identification of characteristics which are consistently employed by skilled performers and conspicuously absent in poor performers may lead to improved teaching and coaching, this study was conducted to analyze selected biomechanical parameters of free throw shooting by players of varying skill. (Article in pdf)

Can scoring accuracy and the selected biomechanical measurements of the angle of trajectory, the velocity of projection, the ratio of height of release to subject height, the amount of backspin on the ball during flight, the velocity of wrist flexion, the degree of trunk inclination, and the ratio of the center of gravity to the base of support in the horizontal plane be used to expose differences and trends of skill in the performance of the one-handed basketball free throw?

Three mutually exclusive groups of college women were filmed during performance of the one-handed basketball free throw. The subjects were members of a beginning level basketball instructional class at Purdue University (n=9); members of the Purdue University women's varsity basketball team (n=7); and members of the United States women's basketball team for the 1973 World University Games (n=9). The testing procedure for each subject consisted of a warm-up period, an accuracy test of twenty free throws and three additional free throws which were filmed. A computer program written for the purpose used coordinates of the body and ball to calculate the angle of trajectory, ratio of height of release to subject height, backspin, velocity of wrist flexion, trunk inclination, and the ratio of the center of gravity to the base of support in the horizontal plane. The measures of wrist flexion, trunk inclination, and center of gravity were taken immediately prior to and immediately after release.

Analysis of variance procedures were used to determine if the groups exhibited differences in any of the ten biomechanical measurements or shooting accuracy. At the .05 level of significance the groups differed significantly on the measures of the height of release ratio, the center of gravity ratio before release, the center of gravity ratio after release, and shooting accuracy. Stepwise regression methods were used to predict the shooter's accuracy percentage and the likelihood of making a given shot. In descending order of importance the best predictors of a shooter's accuracy were the height of release ratio, the angle of trajectory, the wrist flexion velocity after release, the weight of the subject, the wrist flexion velocity before release, the trunk inclination before release, the center of gravity ratio after release and the height of the subject. The likelihood of any given shot's scoring could be predicted best by the height of the subject, the subject's percentage of accuracy, the center of gravity ratio after release, the velocity of projection, and the velocity of wrist flexion before release in that order. By using stepwise discriminant procedures the values of percentage of accuracy, center of gravity ratio after release, subject weight, trunk inclination before release, center of gravity ratio before release, height of release ratio, velocity of wrist flexion before release, and subject height were the best predictors for the group in which each subject should belong.

A similar study using more trials per subject and more subjects per group is recommended.