Effects of curricular activity on students' situational motivation and physical activity levels

The purpose of this study was to examine (a) the effects of three curricular activities on students'situational motivation (intrinsic motivation [IM], identified regulation [IR], external regulation, and amotivation [AM]) and physical activity (PA) levels, and (b) the predictive strength of situational motivation to PA levels. Four hundred twelve students in grades 7-9 participated in three activities (cardiovascular fitness, ultimate football, and Dance Dance Revolution [DDR]) in physical education. ActiGraph GT1M accelerometers were used to measure students' PA levels for three classes for each activity. Students also completed a Situational Motivation Scale (Guay, Vallerand, & Blanchard, 2000) at the end of each class. Multivariate analysis of variance revealed that students spent significantly higher percentages of time in moderate-to-vigorous PA (MVPA) in fitness and football classes than they did in DDR class. Students reported higher lM and IR toward fitness than DDR They also scored higher in IR toward fitness than football. In contrast, students displayed significantly lower AM toward fitness than football and DDR Hierarchical Linear Modeling revealed that IM was the only positive predictor for time in MVPA (p = .02), whereas AM was the negative predictor (p < .01). The findings are discussed in regard to the implications for educational practice.     

Understanding the role of shaft stiffness in the golf swing

Theoretically, shaft stiffness can alter shot distance by increasing clubhead speed or altering clubhead orientation at impact. A 3D forward dynamics model of a golfer and flexible club simulated the downswing. A genetic algorithm optimized the coordination of the model’s muscles (four torque generators) to maximize clubhead speed. The maximum torque output and maximum rate of torque development from the torque generators were varied to simulate the swing of golfers that generate different clubhead speeds. Four shafts of varying stiffness (flexible, regular, stiff, and completely rigid) were entered into these simulations to examine the role that shaft flexibility had on clubhead speed and orientation at impact. Shaft stiffness was found to have a meaningful effect only on clubhead orientation (dynamic loft and dynamic close) at impact. There was no evidence to support the premise that matching the stiffness properties of the shaft with the golfer would improve clubhead speed.     

Impaired motor control after sport-related concussion could increase risk for musculoskeletal injury: Implications for clinical management and rehabilitation

This review presents a conceptual framework and supporting evidence that links impaired motor control after sport-related concussion(SRC)to increased risk for musculoskeletal injury.Multiple studies have found that athletes who are post-SRC have higher risk for musculoskeletal injury compared to their counterparts.A small body of research suggests that impairments in motor control are associated with musculoskeletal injury risk.Motor control involves the perception and processing of sensory information and subsequent coordination of motor output within the central nervous system to perform a motor task.Motor control is inclusive of motor planning and motor learning.If sensory information is not accurately perceived or there is interference with sensory information processing and cognition,motor function will be altered,and an athlete may become vulnerable to injury during sport participation.Athletes with SRC show neuroanatomic and neurophysiological changes relevant to motor control even after meeting return to sport criteria,including a normal neurological examination,resolution of symptoms,and return to baseline function on traditional concussion testing.In conjunction,altered motor function is demonstrated after SRC in muscle activation and force production,movement patterns,balance/postural stability,and motor task performance,especially performance of a motor task paired with a cognitive task(i.e.,dual-task condition).The clinical implications of this conceptual framework include a need to intentionally address motor control impairments after SRC to mitigate musculoskeletal injury risk and to monitor motor control as the athlete progresses through the return to sport continuum.     

Gender differences among sagittal plane knee kinematic and ground reaction force characteristics during a rapid sprint and cut maneuver

Women are more prone to anterior cruciate ligament (ACL) injury during cutting sports than men. The purpose of this study was to examine knee kinematic and ground reaction forces (GRF) differences between genders during cutting. Male and female athletes performed cutting trials while force platform and video data were recorded (180 Hz). Differences (p < . 05) were observed between groups for knee flexion at contact and GRF at maximum knee flexion. Women averaged 5.8 degrees less flexion at contact and 1.0 N. (kg x m x s(-1))(-1) greater GRF at maximum flexion. Knee range of motion and peak GRF variables were not significantly different, but women had greater values. Women exhibited technique characteristics believed to increase ACL injury risk, but men exhibiting similar characteristics were also observed and could also be at risk.     

Optimized versus corrected peak power during friction-braked cycle ergometry in males and females

Abstract

The aim of this study was to compare optimization and correction procedures for the determination of peak power output during friction-loaded cycle ergometry. Ten male and 10 female sports students each performed five 10-s sprints from a stationary start on a Monark 864 basket-loaded ergometer. Resistive loads of 5.0, 6.5, 8.0, 9.5, and 11.0% body weight were administered in a counterbalanced order, with a recovery period of 10 min between sprints. Peak power was greater and occurred earlier, with less work having been done before the attainment of peak power, when the data were corrected to account for the inertial and frictional characteristics of the ergometer. Corrected peak power was independent of resistive load (P > 0.05), whereas uncorrected peak power varied as a quadratic function of load (P < 0.001). For males and females, optimized peak power (971 ± 122 and 668 ± 37 W) was lower (P < 0.01) than either the highest (1074 ± 111 and 754 ± 56 W respectively) or the mean (1007 ± 125 and 701 ± 45 W respectively) of the five values for corrected peak power. Optimized and mean corrected peak power were highly correlated both in males (r = 0.97, P < 0.001) and females (r = 0.96, P < 0.001). The difference between optimized and mean corrected peak power was 37 ± 30 W in males and 33 ± 14 W in females, of which approximately 15 W was due to the correction for frictional losses. We conclude that corrected peak power is independent of resistive load in males and females.     

An evaluation of inertial sensor technology in the discrimination of human gait

Abstract

Inertial sensors may provide the opportunity for broader and more cost effective gait analysis; however some questions remain over their potential use in this capacity. The aim of the study was to determine whether an inertial sensor could discriminate between normal walking, fast walking, and running. A single group crossover design was used to compare acceleration profiles between three gait conditions: normal walking, fast walking, and running. An inertial sensor was placed on the sacrum of 12 participants (6 male, 6 female) who performed 3 trials of each gait condition on both overground and treadmill settings. A significant difference (P < 0.001) in the occurrence of heel strike in the gait cycle was found between running and both walking conditions. No differences were seen between overground and treadmill in any condition or variable. The results indicate that a single sacral mounted inertial sensor can differentiate running from normal walking and fast walking using temporal gait event measures. This study indicates that inertial sensors can differentiate walking from running gait in healthy individuals which may have potential for application in the quantification of physical activity in the health and exercise industry.     

Effect of Mastering Swim Skills on Older Adults' Self-Efficacy

Abstract

Two groups of 23 junior high school boys were tested before and after an eight weeks' progressive resistance training program. The experimental group participated in this program, but the control group took part only in regularly scheduled physical education classes. At the end of the eight weeks, it was found that the experimental group increased their ability to do pull-ups, push-ups, the Harvard Step Test, Dodge run, the Burpee test, and trunk extension and flexion. The control group improved in the Dodge run, the Burpee test, push-ups, and trunk extension. In no case did the improvement of the control group exceed the improvement of the experimental group. The experimental group also increased in anthropometric measurements. Medical examinations indicated that no harmful effects were experienced by either group.     

Cardiac Dimensions in Elite Young Track Athletes

The purpose of the study was to compare young sprint and distance runners for changes in their cardiac dimensions with increased age (10–17 years) or body surface area (1–2 m²). Echocardiographic dimensions were obtained on 73 male track athletes competing in the 1983 National Age Group Track and Field Association championships. Each group of athletes was also compared with a hypothetical normal population (matched for weight and age) generated from prediction equations derived by Henry, Gardin, & Ware (1980). The cardiac dimensions examined were: Left ventricular internal diameter, left ventricular posterior wall thickness, and interventricular septum thickness. The male distance runners (n = 38) had a significantly greater increase in left ventricular posterior wall thickness and interventricular septum thickness with increasing age or increasing body surface area compared to the sprinters (n = 35) or compared to the predicted normal population. The left ventricular internal diameter was not significantly different between the groups. These results indicate that the hearts of male distance runners are undergoing a training hypertrophy whereas the hearts of sprinters are no different than hearts in a normal population. The changes in cardiac dimensions of these young athletes run counter to the generalizations stated for adult athletes: That endurance training enlarges the left ventricular internal diameter, but does not increase the left ventricular posterior wall or interventricular septum thickness.     

Evaluating standards-based assessment rubrics in a postgraduate public health subject

Standards-based assessment rubrics are recognised as an important tool for ensuring clear criteria in higher education. Most of the available evidence on rubrics comes from studies with face-to-face undergraduate students. Our study evaluated the introduction of rubrics into a postgraduate subject that included both online and face-to-face students. We conducted formative evaluation with former students to develop the rubrics, as well as surveying current students for process and impact evaluation, supplemented with a focus group. Process results showed that the rubrics were used widely and were generally considered to be of at least some use. Clarity of the rubrics was the main issue affecting perceived usefulness, particularly for the assessment tasks that had undergone comparatively less formative evaluation. Impact evaluation showed mixed results, with students that reported always using rubrics having higher marks on average compared to students who did not always use the rubrics. However, an expected improvement in marks across the whole student cohort compared to previous years did not eventuate, although this could be explained by a number of factors independent of the rubrics. Our results provide some evidence for the use of rubrics in postgraduate and online settings but highlight the need for rigorous formative evaluation.