Composition of Practice: Influence on the Retention of Motor Skills

Abstract

The purpose of these experiments was to investigate further the variable practice effect found by Shea and Kohl (1990). Experiment 1 was an initial attempt to determine the locus of the retention benefits demonstrated by subjects provided variable practice experiences. All groups received 20 acquisition blocks consisting of five test trials per block at a target of 150 N. The interval between test trials was either unfilled or filled, with additional trials consisting of the same target force, variable target forces, or practice on an unrelated motor task. The results indicated retention was not incremented (relative to an unfilled interval) by requiring subjects to perform an unrelated motor task in the intertest–trial interval. However, when the intertest–trial interval was filled with practice on related motor tasks, retention was significantly improved. Experiment 2 assessed the impact of increasing the number of related motor tasks interpolated between test trials. The results indicated filling the intertest–trial interval with one motor task resulted in large retention benefits relative to an unfilled interval. Further increases in the number of related motor tasks (3) interpolated between test trials resulted in only modest increments to retention. The results were consistent with the elaboration perspective proposed by Shea and Zimny (1983). The elaboration perspective proposes that the simultaneous presence of related items in working memory facilitates interitem elaborative and distinctive processing that ultimately results in retention benefits.     

Value Orientations of Preservice Teachers

Abstract

Curriculum theorists have acknowledged, the critical role that beliefs and values play in the decisions that teachers make, but very little is known about how teachers' value profiles develop. The purpose of this investigation was to examine the educational value orientations of a group of physical education preservice teachers (N = 16) enrolled in an elementary methods course and to investigate the link between value profiles and teacher behaviors. Value profiles were assessed using the Value Orientation Inventory (Ennis & Hooper, 1988). The results indicated that teachers in training entered field-based experiences with defined value profiles, but that these profiles were not stable constructs. Priorities within competing value orientations fluctuated over the course of a semester. Possible explanations for the changes that occurred and implications for teacher education programs are discussed.     

Effects of Proximity on the Choice to Be Physically Active or Sedentary

The link between physical activity and weight loss has precipitated interest in interventions to foster adherence to exercise. It has been suggested that treatment effects, when significant, should be analyzed to determine theory-based mediators. This research assessed possible mediation of changes in Physical Self-Concept, Exercise Self-Efficacy, Total Mood Disturbance, and Body Areas Satisfaction scores on the relationship between exercise session attendance and participation by obese women in a 6-month treatment based on tenets of social cognitive theory (n = 73) or a control condition (n = 64). Participation in the treatment was associated with significantly greater exercise session attendance and significantly greater improvements in Physical Self-Concept, Exercise Barriers Self-Efficacy, and Body Areas Satisfaction. Overall, changes in the assessed psychological factors demonstrated significant mediation of the association between group membership and exercise session attendance, R² = .23, with only change in Physical Self-Concept scores providing a significant unique contribution. Extensions of this research across different sample types, and with longer durations, were suggested to refine theory and, ultimately, improve exercise adherence treatments.     

Use of NSE/PS2m-transgenic mice in the study of the protective effect of exercise on Alzheimer's disease

In its late stage, Alzheimer's disease results in progressive muscle weakness in the arms and legs. The aim of this study was to determine whether mice expressing the skeletal muscle-specific mutant PS2 gene (a model of Alzheimer's disease) are a useful experimental system to study the protective effect of exercise on Aβ-42 reduction, improvement of behavioural function and changes in metabolic parameters. With this aim in mind, the transgenic mice were subjected to treadmill exercise for 3 months. The results showed that in transgenic mice, but not in normal mice, treadmill exercise resulted in a reduction of Aβ-42 deposits and an improvement in behavioural function, thereby restoring normal concentrations of total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and triglyceride. Thus, exercise may represent a practical therapeutic strategy for use with human patients with Alzheimer's disease.     

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.     

Kinematics,coordination, variability,and biological noise in the prone flutter kick at different levels of a “learn-to-swim” programme

Abstract

The purpose of this study was to establish the characteristics of the movement patterns common to flutter kicking of skilled swimmers and to determine how the movement patterns of swimmers at different levels of a “learn-to-swim” programme differ from those of skilled swimmers. Also, the nature of the skill afforded the opportunity to investigate learning of a cyclical multi-joint task from a motor control perspective. The underwater motion of nine children representing three levels of a “learn-to-swim” programme and 10 skilled swimmers were video-recorded while performing nine cycles of prone flutter kicking. Kinematics including joint angular motion and coordination of joint actions were calculated. Fourier analysis was applied to determine the frequency composition of the vertical undulations of the hip, knee, and ankle and to calculate the velocity of the body wave travelling caudally from hip to ankle. Fourier analysis also enabled investigation of biological noise, as distinct from variability. The results indicated the desired joint angles and coordination towards which learners could be guided. An index based on the ratio of hip – knee and knee – ankle body wave velocities showed that the inter-joint coordination of most learners was not appropriate for effective flutter kicking. There was strong evidence to suggest that skilled performance in flutter kicking is characterized by sequencing of joint actions to produce a single sinusoidal body wave moving caudally with not decreasing and preferably increasing velocity, low biological noise, and small variability.     

Cardiopulmonary loading in motocross riding

Abstract

The present study was designed to examine physiological responses during motocross riding. Nine Finnish A-level motocross riders performed a 15-min ride at a motocross track and a test of maximal oxygen uptake ([Vdot]O_2max) in the laboratory. Cardiopulmonary strain was measured continuously during the ride as well as in the [Vdot]O_2max test. During the ride, mean [Vdot]O₂ was 32 ml · kg^?1 · min^?1 (s = 4), which was 71% (s = 12) of maximum, while ventilation (V _E) was 73% (s = 15) of its maximum. The relative [Vdot]O₂ and V _E values during the riding correlated with successful riding performance (r = 0.80, P < 0.01 and r = 0.79, P < 0.01, respectively). Mean heart rate was maintained at 95% (s = 7) of its maximum. Mean blood lactate concentration was 5.0 mmol · l^?1 (s = 2.0) after the ride. A reduction of 16% (P < 0.001) in maximal isometric handgrip force was observed. In conclusion, motocross causes riders great physical stress. Both aerobic and anaerobic metabolism is required for the isometric and dynamic muscle actions experienced during a ride.     

Referee bias contributes to home advantage in English Premiership football

Abstract

Officiating bias is thought to contribute to home advantage. Recent research has shown that sports with subjective officiating tend to experience greater home advantage and that referees' decisions can be influenced by crowd noise, but little work has been done to examine whether individual referees vary in their home bias or whether biased decisions contribute to overall home advantage. We develop an ordinal regression model to determine whether various measures of home advantage are affected by the official for the match and by crowd size while controlling for team ability. We examine 5244 English Premier League (EPL) match results involving 50 referees and find that home bias differs between referees. Individual referees give significantly different levels of home advantage, measured as goal differential between the home and away teams, although the significance of this result depends on one referee with a particularly high home advantage (an outlier). Referees vary significantly and robustly in their yellow card and penalty differentials even excluding the outlier. These results confirm that referees are responsible for some of the observed home advantage in the EPL and suggest that home advantage is dependent on the subjective decisions of referees that vary between individuals. We hypothesize that individual referees respond differently to factors such as crowd noise and suggest further research looking at referees' psychological and behavioural responses to biased crowds.     

Modifications to the Bassin Anticipation Timer

Abstract

The purpose of this study was to ascertain and to analyze the attitudes of men and women undergraduate students at the University of California, Santa Barbara, concerning the desirability of intensive athletic competition for girls and women. In January 1966, a questionnaire and an attitude inventory were administered to a random stratified sample of 300 undergraduate students. The attitude inventory consisted of 38 statements which were divided into four categories— social-cultural, mental-emotional, physical, and personality. Two hundred and eighty-four questionnaires and attitude inventories (94.7 percent) were completed and were submitted to statistical analysis.

Although the population was found to be favorable in attitude, the range of scores indicated that considerable differences of opinion existed concerning the desirability of athletic competition for girls and women.