The main purpose of this study was to develop a model for calculating forces produced by a swimmer’s hand, with the thumb adducted, accelerating in the direction of flow. The model included coefficients to account for the velocity and acceleration of the hand. These coefficients were designed to calculate forces in the direction opposite the motion (drag) and two components of lift orthogonal to the direction of motion. To determine the coefficients, three-dimensional forces acting on a resin cast of a swimmer’s hand were recorded while accelerating the hand from rest to 0.45 m · s−1 and 0.6 m · −1 in a towing tank. The hand orientation was varied throughout the entire range at 5° increments. Three-dimensional surfaces describing the magnitude of the coefficients as functions of pitch and sweepback angle were produced. It was found that acceleration coefficients as well as velocity coefficients are required for accurate modeling of the forces produced by the hand in swimming. The forces generated by the hand are greatest when pitch angles approach 90° due to the large contribution by the drag component. However, at pitch angles near 45° and sweepback angles near 45° and 135°, lift forces contribute substantially.
Ross H. Sanders
Jeffrey N. Howard
The game of baseball and its internal cryptic communication system has always been vulnerable to sign stealing. By systematically studying the signals of an opponent so as to decrypt and intercept opponent communications, one can garner valuable insight into future events and strategies. Such “theft of signals” can lead teams to frequently change their sign indicator, should they suspect it has been compromised. The current paper presents a theoretical process of “hot” sign indicator obfuscation whereby the pitcher and catcher use unique hot indicator values that are generated after each pitch via an algorithm derived from randomly changing situational and/or scoreboard data.
Brenda A. Riemer
This study is an examination of the identity formation of lesbians in sport and how lesbians interpreted the softball environment with regard to social support and the ability to be open about their lesbianism. Twenty four women on summer slow pitch softball teams, and 5 spectators, participated in qualitative interviews. Responses were consistent with a model of lesbian identity formation that included preconformist, conformist, post-conformist, lesbian conformist, and lesbian post-conformist levels. The support these women received from softball players helped them to come out to others and to enter the lesbian community.
Ross H. Sanders
The purpose of this study was to investigate technique in the eggbeater kick and to identity factors contributing to height that can be maintained. The kinematics of the lower limbs of 12 players ranging in ability from novice to elite were quantified using three-dimensional videographic techniques. Mean height of the vertex of the head with respect to water level was used as the measure of performance. These heights ranged from 0.22 m to 0.42 m. The mean of the squared fool velocity (r = .85, p < .01), the percent contribution of the vertical and anteroposterior components of foot velocity (r = −.72 and r = .72, respectively, p < .05) were strongly related to height. There were also substantial contributions due to mediolateral motion by all players, but this was not statistically related to height. Pitch angles were generally small throughout the kick cycle. Elite players maximized me period of positive pitch by appropriate use of ankle dorsi-flexion and plantar-flexion and eversion and inversion. The foot orientadons and flow directions of the elite players suggested that effective technique involved sculling actions to utilize lift forces.
Michael E. Feltner and Jesús Dapena
The motion of a body segment is determined by joint torques and by the motions of the segments proximal or distal to it. This paper describes a three-dimensional model that was used to determine the effects of the shoulder and elbow joint torques and of the upper trunk and arm motions on the angular accelerations of the arm segments during baseball pitching. Equations were developed to fractionate the three-dimensional components of the angular acceleration vector of each segment into angular acceleration terms associated with the joint torques made on the segment, and into various “motion-dependent” angular acceleration terms associated with the kinematic variables of the arm segments. Analysis of the values of the various motion-dependent angular acceleration terms permitted the determination of their contributions to the motion of the segment. Although the model was developed to provide further understanding of the mechanics of the throwing arm during baseball pitching, it can be used to analyze any two-segment two-dimensional or three-dimensional motion.
Michael E. Powers
This paper reviews the role of the rotator cuff during two key phases of the pitching sequence and presents a training program for these muscles. The program uses a periodization design consisting of three stages, beginning with a high-resistance/low-repetition eccentric strengthening stage. This is followed by a low-resistance/high-repetition stage for training muscular endurance. The core exercises for these two stages are prone external rotation in the 90/90 position, prone horizontal abduction, side-lying D2 flexion pattern, supine internal rotation in the 90/90 position, prone elevation with 100° of shoulder abduction and external rotation, and standing scapular plane elevation. The final stage of the program uses high-speed functional exercises: 90/90 external rotation, 90/90 internal rotation, D2 PNF flexion pattern, D2 PNF extension pattern, supine plyometric 90/90 internal rotation with a medicine ball, and the “arm whip” through the D2 PNF flexion pattern. The goal of this program is to prepare the muscles for the stresses of pitching and prevent shoulder injuries.
Shihui Chen, Ernest Lange, Paul Miko, Jiabei Zhang and Daniel Joseph
The purpose of this study was to investigate the effectiveness of the progressive time delay (PTD) procedure on teaching gross motor skills to adult males with severe mental retardation. A multiple probe design across three skills and replicated across 4 participants was utilized. Results indicated that a PTD procedure with a 0 to 5 s delay was effective in teaching 4 participants three gross motor skills (tee-ball batting, softball pitching, croquet striking) over a period of 13 weeks. Data on effectiveness were analyzed in terms of the number of instructional sessions (M = 9.58), the number of trials (M = 105.41), the number of min (M = 84.66), and the number of performing errors to criterion (M = 4.08%). A maintenance level (M = 96.87%) was also determined across 4 participants and three skills on the 1st, 4th, 14th, and 24th sessions after terminating the PTD instruction.
Sarah Kelly, Len Coote, T. Bettina Cornwell and Anna McAlister
This research provides insight into the complex relationship between consumer response to persuasion attempts and skepticism, suggesting that erstwhile targets may be swayed by campaigns pitched as a form of entertainment. The authors examine consumer responses to an important sponsorship-leveraging tool: sponsorship-linked advertising (SLA). A theoretical model of consumer response to SLA is proposed, drawing on important resistance mechanisms to persuasion, including ad skepticism, attributed advertiser motives, and the nature of thoughts. Results confirm existing research on consumer skepticism suggesting its transitory nature and hence potential for advertisers to strategically temper it through specific cues in ad execution. Differential processing between SLA and traditional advertising is supported, such that SLA elicits more favorable cognitive response.
Dennis Smart, Jason Winfree and Richard Wolfe
Smart and Wolfe (2003) assessed the concurrent contribution of leadership and human resources to Major League Baseball (MLB) team performance. They found that player resources (defense/pitching and offence/batting) explained 67% of the variance in winning percentage, whereas leadership explained very little (slightly more than 1%) of the variance. In discussing the minimal contribution of leadership to their results, the authors suggested that future studies expand their operationalization of leadership. That is what is done in this study. Finding that the expanded operationalization has limited effect in explaining the contribution of leadership, we take an alternative tack in attempting to understand leadership in MLB. In addition, we estimate a production frontier (based on offensive and defensive resources), determine the efficiency of MLB managers relative to that frontier, and investigate the extent to which manager efficiency can be explained by manager characteristics. Finally, manager characteristics are related to manager compensation.
Carsten H. Larsen, Dorothee Alfermann, Kristoffer Henriksen and Mette K. Christensen
The purpose of this article is to present practitioners and applied researchers with specific details of an ecological-inspired program and intervention in a professional football (soccer) club in Denmark. Based on an ecological agenda, the aim is to reinforce the culture of psychosocial development in the daily practice of a professional football academy, provide the skills required to succeed at the professional level and create stronger relations between the youth and professional departments. The authors suggest six principles as fundamental governing principles to inform an intervention inspired by the holistic ecological perspective. Descriptions of the intervention program and findings are presented in four interconnected steps. Insights are provided into delivery of workshops, the supervision of the coach, on-pitch training, evaluation of the program, and integrating sport psychology as a part of the culture within the club.