The Kinematics and Kinetics of the Running Pattern of Two-, Four-, and Six-Year-Old Children

Abstract

Selected kinematic and kinetic variables in the running pattern of 2-, 4-, and 6-year-old children were investigated. Cinematographic records and force-plate tracings were used to study the running patterns of the 28 Caucasian subjects, 15 male and 13 female. A 2 × 3 (sex × age) factorial analysis of variance was used to determine whether effects of variation between and within age and sex factors for each of the dependent variables of selected kinematic (displacement and velocity) and kinetic (ground reaction force) variables were significant. The running speeds improved with age. Although height and weight gains influenced the improvement shown in performance, certain biomechanical variables also contributed to the development of the running pattern. In the majority of the selected kinematic and kinetic variables there were significant differences between the 2-year-old group and the other two groups. Where there were significant differences in the variables, the differences tended to be in displacement, velocity, and magnitude of force measures, rather than in time of occurrence measures. Significant differences between male and female subjects appeared in five kinematic variables related to the swing leg.     

Assimilation Effects in Coincident Timing Responses

Abstract

The purpose of the study was to investigate ways in which gender-related perceptions and actions influenced students' construction of realities in curriculum-in-action in secondary school physical education. The participants were junior and senior secondary school students in a midwestern city in the United States. Data collection methods included observations and interviews. Data were analyzed with inductive analytical procedures. The findings of the study revealed that a majority of the female and male students reproduced traditionally dominant forms of femininity and masculinity. Female students patterned their behavior consistent with feminine ideology in selecting and participating in class activities, and male students chose and participated in class activities along masculine conceptions. The results were interpreted with reproduction and resistance theories. While femininity and masculinity cultures were reproduced through students' choice of activities and participation patterns, these cultures were resisted through students' construction of oppositional behavior.     

Specificity of a Maximal Step Exercise Test

To adhere to the principle of “exercise specificity” exercise testing should be completed using the same physical activity that is performed during exercise training. The present study was designed to assess whether aerobic step exercisers have a greater maximal oxygen consumption (max VO₂) when tested using an activity specific, maximal step exercise test (SET; arms and legs) versus a maximal running test (legs only). Female aerobic step exercisers (N=18; 20.7 ± 1.5 years) performed three maximal graded exercise tests (GXTs): 2 SETs; 1 treadmill test (TMT). The SET consisted of six 3-min progressive stages of alternate lead, basic step, basic step with biceps curls, knee raise with pull-down, repeater knee with pull-down, lateral lunge with pull-down, and side squat with shoulder presses. Stepping rate was 32 steps· min^?1 on an 8-in (20.32 cm) step for stages 1–3, and a 10-in (25.4 cm) step for stages 4–6. Submaximal and maximal heart rate (HR) and oxygen consumption (VO₂) were recorded at the end of each stage. Test–retest reliability for the first five stages of the SET ranged from .91 to .97 for HR, and from .84 to .96 for VO₂. Maximal HR was significantly greater (p =.0001) for the SET (200 ± 6.2 beats·min^?1) as compared to the TMT (193 ± 7.9 beats·min^?1). No significant difference was found for max VO₂ (42.9 ± 8.5, 41.2 ± 5.9 ml·kg^?1·min^?1, p =.14). The SET was a valid and reliable protocol for assessing responses of these aerobic step exercisers; however, max VO₂ from a TMT did not differ significantly from the SET. Conversely, max HR obtained from the criterion TMT was 7 beats·min^?1 lower than from the SET. If a training HR for step exercise (arms and legs exercise) is prescribed based on the max HR from treadmill exercise (legs only), then the training HR should be calculated from a TMT max HR that has been increased by 7 beats·min^?1 to obtain an intensity of step exercise comparable to that of running.     

System Analysis for Oxygen Uptake Kinetics with Step and Pseudorandom Binary Sequence Exercise in Endurance Athletes

We examined whether the system analysis for step and pseudorandom binary sequence (PRBS) exercises could be useful to characterize oxygen uptake (VO₂) kinetics of female sedentary subjects and endurance athletes. Breath-by-breath VO₂ was determined during step- and PRBS-cycle ergometer exercises. The time course of the VO₂ kinetics was evaluated by the time constant of the second phase, which should reflect the adjustment of the oxidative metabolism at the skeletal muscle level. The VO₂ kinetics were significantly faster in long-distance runners than in sedentary subjects for both exercises. A significant relationship was observed in the VO₂ kinetics obtained from step and PRBS exercises. In each group, there was no significant difference in the VO₂ kinetics for step and PRBS exercises. These results indicated that the system analysis with PRBS exercises revealed the faster VO₂ kinetics in endurance athletes than in sedentary subjects.     

Dispositions of elite-level Australian rugby coaches towards game sense: characteristics of their coaching habitus

Bourdieu's analytic concept of habitus has provided a valuable means of theorising coach development but is yet to be operationalised in empirical research. This article redresses this oversight by drawing on a larger study that inquired into how the ‘coaching habitus’ of elite-level Australian and New Zealand rugby coaches structured their interpretation and use of the Game Sense approach to coaching to illustrate how habitus can be operationalised. It focuses on the identification of characteristics of the individual coaching habitus of four elite-level Australian rugby coaches and how they shape their interpretation and use of Game Sense. Drawing on suggestions made by Lau, we identify the characteristics of four individual ‘coaching habitus’ by examining their views on: (1) the characteristics of good coaches; (2) characteristics of great rugby players and how to develop them; and (3) their dispositions towards innovation in coaching.     

A Multidimensional Timing Device for Cinematography

Abstract

Six tests were developed for the purpose of measuring selected basic skills in ice hockey. The test-retest method indicated four tests as reliable. Validity coefficients for each of the four tests when compared to subjective ranking in each skill ranged from .75 to .96. Intercorrelations were computed among the tests. The puck carry test correlated with the other three tests and was determined the best single-item for measuring overall ability. It was concluded that an ice hockey test battery should include at least three of the tests.     

The Relationship between Perceptual and Motor Abilities

Abstract

Eighty randomly selected kindergarten pupils were administered one of four figure-ground variations of a gross motor task in order to determine the effects of the various patterns on the performance of the task. All subjects were administered the figure-ground subtest of the Frostig Developmental Test of Visual Perception and the gross motor task which involved walking in a lateral direction between the rungs of a ladder placed in a horizontal position over a floor pattern. An analysis of variance revealed significant differences in the error-time performance among the groups. Pearson product-moment correlation techniques revealed significant relationships between the gross motor task and the Frostig test.     

Buoyancy of College Women as Predicted by Certain Anthropometric Measures

Abstract

A discriminant analysis equation was computed to predict buoyancy from 17 anthropometric variables. The subjects for the study were 74 Caucasian women and 81 Negro women university students. The Negro group had less buoyancy and was the only group for which it was possible to compute a discriminant equation as the Caucasian group did not have any nonfloaters.     

Spot Reduction of Subcutaneous Adipose Tissue

Abstract

This study was designed to determine if the skinfold measurements on an exercised arm would decrease as a result of regular weight training with that arm. Thirty-two subjects completed three sets of 7-RM curls and three sets of 7-RM triceps extensions on either a daily or an alternate day schedule for a period of 6 weeks. The nonexercised arm was measured to establish the specificity of the spot reduction on the exercised arm. The results indicate that hard exercise in a specific area of the arm will result in a reduction of the subcutaneous adipose tissue in that area.