FREE hit counter and Internet traffic statistics from

Thursday, July 06, 2006

Baseball and the Academy

My father-in-law who is a medical librarian and baseball fan occasionally finds abstracts or articles relevant to baseball. Here's a recent batch that I thought you might find interesting (who says academics are boring?)

The relationship between age and baseball pitching kinematics in professional baseball pitchers.
American Sports Medicine Institute

Joint range of motion and physical capacities have been shown to change with age in both throwing athletes and non-athletes. The age of professional baseball pitchers could span from late teens to mid-40s. However, the effects of age on the pitching kinematics among professional baseball pitchers are still unknown. In this study, 67 healthy professional baseball pitchers were tested using a 3D motion analysis system. Their mean age was 23.7+/-3.3 years (range 18.8-34.4). The 12 pitchers more than one standard deviation older than the mean (i.e., older than 27.0 years) were categorized into the older group, and the 10 pitchers more than one standard deviation younger than the mean (i.e., younger than 20.4 years) were defined as the younger group. In all, 18 kinematic variables (14 position and 4 velocity) were calculated, and Student's t-tests were used to compare the variables between the two groups. Six position variables were found to be significantly different between the two groups. At the instant of lead foot contact, the older group had a shorter stride, a more closed pelvis orientation, and a more closed upper trunk orientation. The older group also produced less shoulder external rotation during the arm cocking phase, more lead knee flexion at ball release, and less forward trunk tilt at ball release. Ball velocity and body segment velocity variables showed no significant differences between the two groups. Thus, differences in specific pitching kinematic variables among professional baseball pitchers of different age groups were not associated with significant differences in ball velocities between groups. The current results suggest that both biological changes and technique adaptations occur during the career of a professional baseball pitcher.

An examination of the "hot hand" in professional golfers.
Department of Psychology, University of North Texas

A study investigated the "hot hand" among professional golfers. Hole-to-hole scores within 747 tournaments from a randomly chosen group of 35 players on
the 1997 PGA Tour were analyzed. Contingency analyses gave no evidence for the "hot hand". Players were just as likely to score a birdie or better following a par or worse hole as make a birdie or better following a birdie or better hole. These results are consistent with those found for individual players in baseball and basketball.

I thought this was interesting since the hot hand is also of interest in baseball. It also made me wonder just where does one go to get PGA data?.

Naive beliefs in baseball: systematic distortion in perceived time of apex for fly balls.
Department of Psychology, Ohio State University-Mansfield

When fielders catch fly balls they use geometric properties to optically maintain control over the ball. The strategy provides ongoing guidance without indicating precise positional information concerning where the ball is located in space. Here, the authors show that observers have striking misconceptions about what the motion of projectiles should look like from various perspectives and that they estimate when the physical apex of a fly ball occurs to be far later than actual, irrespective of baseball experience. Their estimations are consistent with the highest point they are looking at as the ball approaches, not with the physical apex. These findings introduce a new and robust effect in intuitive perception in which people confuse their perceptual perspective with the physical situation that they mentally represent.

Determining whether a ball will land behind or in front of you: not just a combination of expansion and angular velocity.
Max Planck Institute for Biological Cybernetics

We propose and evaluate a source of information that ball catchers may use to determine whether a ball will land behind or in front of them. It combines estimates for the ball's horizontal and vertical speed. These estimates are based, respectively, on the rate of angular expansion and vertical velocity. Our variable could account for ball catchers' data of Oudejans et al. [The effects of baseball experience on movement initiation in catching fly balls. Journal of Sports Sciences, 15, 587-595], but those data could also be explained by the use of angular expansion alone. We therefore conducted additional experiments in which we asked subjects where simulated balls would land under conditions in which both angular expansion and vertical velocity must be combined for obtaining a correct response. Subjects made systematic errors. We found evidence for the use of angular velocity but hardly any indication for the use of angular expansion. Thus, if catchers use a strategy that involves combining vertical and horizontal estimates of the ball's speed, they do not obtain their estimates of the horizontal component from the rate of expansion alone.

Optical trajectories and the informational basis of fly ball catching.
The RAND Corporation

D. M. Shaffer and M. K. McBeath (see record 2002-02027-006) plotted the optical trajectories of uncatchable fly balls and concluded that linear optical trajectory is the informational basis of the actions taken to catch these balls. P. McLeod, N. Reed, and Z. Dienes (see record 2002-11140-016) replotted these trajectories in terms of changes in the tangent of optical angle over time and concluded that optical acceleration is the informational basis of fielder actions. Neither of these conclusions is warranted, however, because the optical trajectories of even uncatchable balls confound the information that is the basis of fielder action with the effects of those same actions on these trajectories. To determine the informational basis of fielder action, it is necessary to do the control-theory-based Test for the Controlled Variable, in which the informational basis of catching is found by looking for features of optical trajectories that are protected from experimentally or naturally applied disturbances.

No comments: