Validity and reliability of a linear positional transducer across commonly practised resistance training exercises     

Harry F. Dorrell  Joseph M. Moore  Mark F. Smith  Thomas I. Gee 《Journal of sports sciences》2019,37(1):67-73

This study investigated the validity and reliability of the GymAware PowerTool (GPT). Thirteen resistance trained participants completed three visits, consisting of three repetitions of free-weight back squat, bench press, deadlift (80% one repetition maximum), and countermovement jump. Bar displacement, peak and mean velocity, peak and mean force, and jump height were calculated using the GPT, a three-dimensional motion capture system (Motion Analysis Corporation; 150 Hz), and a force plate (Kistler; 1500 Hz). Least products regression were used to compare agreeability between devices. A within-trial one-way ANOVA, typical error (TE; %), and smallest worthwhile change (SWC) were used to assess reliability. Regression analysis resulted in R² values of >0.85 for all variables excluding deadlift mean velocity (R² = 0.54–0.69). Significant differences were observed between visits 3-2 for bench press bar displacement (0.395 ± 0.055 m; 0.383 ± 0.053 m), and deadlift bar displacement (0.557 ± 0.034 m; 0.568 ± 0.034 m). No other significant differences were found. Low to moderate TE (0.6–8.8%) were found for all variables, with SWC ranging 1.7–7.4%. The data provides evidence that the GPT can be used to measure kinetic and kinematic outputs, however, care should be taken when monitoring deadlift performance.  相似文献   

‘The influence of overseas coaching and management on the occupational subculture of English professional soccer: views from the dugout’     

Graham Smith 《Soccer & Society》2019,20(1):61-85

It is generally acknowledged that expatriate British players and coaches were instrumental in soccer’s radiant global diffusion and that different technical and tactical emphases developed according to particular geographical locations and cultural milieu. As the twentieth century unfolded, the trend reversed with increased inward flows of elite foreign playing and coaching labour challenging the distinctive and erstwhile dominant occupational culture of the English game. This paper explores the dynamics and tensions of subcultural modification and adaptation at the British: migrant coaching talent interface. Owing to issues associated with access, the occupational subculture of elite-level football is impenetrable to most researchers. Previous employment in professional soccer allowed this author to overcome such impediments, permitting access to a range of high-status national and international players and coaches (n = 25) affecting and affected by occupational subcultural change. This enabled a distinctive research platform combining insider knowledge and grounded experience with academic orthodoxy. The paper is built upon primary data collected in semi-structured interviews and critical analysis of emerging themes. In doing so, it offers a fresh dimension to understanding the impact of globalization on elite professional English soccer. Key findings indicated the opinion of British coaches on the impact of this foreign influx polarized. Although many demonstrated an enlightened standpoint, adopting innovative practices introduced by overseas coaching talent, these views were counter-balanced by evidence of a myopic arrogance bordering on xenophobic resistance to change in what now has to be considered the global rather than the ‘English’ game.  相似文献   

Considerations for the use of functional principal components analysis in sports biomechanics: examples from on-water rowing     

John Warmenhoven  Stephen Cobley  Conny Draper  Andrew Harrison  Norma Bargary  Richard Smith 《Sports biomechanics / International Society of Biomechanics in Sports》2019,18(3):317-341

The proliferation of new biomechanical technology in laboratory and field settings facilitates the capture of data-sets consisting of complex time-series. An understanding of the appropriate statistical approaches for analysing and interpreting these data-sets is required and the functional data analysis (FDA) family of statistical techniques has emerged in the biomechanical literature. Given the use of FDA is currently in its infancy with biomechanical data, this paper will form the first of a two part series aiming to address practical issues surrounding the application of FDA techniques in biomechanics. This work focuses on functional principal components analysis (fPCA), which is explored using existing literature and sample data from an on-water rowing database. In particular methodological considerations for the implementation of fPCA such as temporal normalisation of data, removal of unwanted forms of variation in a data-set and documented methods for preserving the original temporal properties within a set of curves are explored in detail as a part of this review. Limitations and strengths of the technique are outlined and recommendations are provided to encourage the appropriate use of fPCA within the field of applied sports biomechanics.  相似文献   

Classroom management: Approaches of regular education teachers and learning disability resource teachers     

Douglas K. Smith 《Psychology in the schools》1983,20(3):363-366

The approaches to classroom management of classroom teachers and learning disability resource teachers were examined. Significant differences in overall approach to classroom management were indicated, with classroom teachers displaying a more sensitizing (punitive) approach to classroom management. Classroom teachers pursuing graduate training in learning disabilities, as compared to elementary education or reading, displayed a significantly less sensitizing approach to classroom management.  相似文献   

Feedback: Task analysis—does it get us to where we really oughta wanta go?     

Bill Brooks  Arthur De W. Smith 《Performance Improvement》1980,19(7):25-27

  相似文献   

Sibling incest: a study of the dynamics of 25 cases   总被引：1，自引：0，他引：1  

H Smith  E Israel 《Child abuse & neglect》1987,11(1):101-108

  相似文献   

Effects of a motivational climate inntervention for coaches on young athletes' sport performance anxiety     

Smith RE  Smoll FL  Cumming SP 《运动与训练心理学杂志》2007,29(1):39-59

The mastery approach to coaching is a cognitive-behavioral intervention designed to promote a mastery-involving motivational climate, shown in previous research to be related to lower anxiety in athletes. We tested the effects of this intervention on motivational climate and on changes in male and female athletes'cognitive and somatic performance anxiety over the course of a basketball season. Hierarchical linear modeling analyses revealed that the athletes in the intervention condition perceived their coaches as being more mastery-involving on the Motivational Climate Scale for Youth Sports when compared to athletes in an untreated control condition. Relative to athletes who played for untrained coaches, those who played for the trained coaches exhibited decreases on all subscales of the Sport Anxiety Scale-2 and on total anxiety score from preseason to late season. Control group athletes reported increases in anxiety over the season. The intervention had equally positive effects on boys and girls teams.  相似文献   

A comparison of self-focus versus attentional explanations of choking     

Wilson M  Chattington M  Marple-Horvat DE  Smith NC 《运动与训练心理学杂志》2007,29(4):439-456

This study examined attentional processes underlying skilled motor performance in threatening situations. Twenty-four trained participants performed a simulated rally driving task under conditions designed either to direct the focus of attention toward the explicit monitoring of driving or a distracting secondary task. Performance (lap time) was compared with a "driving only" control condition. Each condition was completed under nonevaluative and evaluative instructional sets designed to manipulate anxiety. Mental effort was indexed by self-report and dual-task performance measures. The results showed little change in performance in the high-threat explicit monitoring task condition, compared with either the low-threat or the high-threat distraction conditions. Mental effort increased, however, in all high- as opposed to low-threat conditions. Performance effectiveness was therefore maintained under threat although this was at the expense of reduced processing efficiency. The results provide stronger support for the predictions of processing efficiency theory than self-focus theories of choking.  相似文献   

Electricity in plants     

Edwin Smith 《Journal of The Franklin Institute》1870,89(1):69-71

  相似文献   

Carbohydrate and carbohydrate + protein for cycling time-trial performance     

Osterberg KL  Zachwieja JJ  Smith JW 《Journal of sports sciences》2008,26(3):227-233

Carbohydrate intake during endurance exercise delays the onset of fatigue and improves performance. Two recent cycling studies have reported increased time to exhaustion when protein is ingested together with carbohydrate. The purpose of the present study was to test the hypothesis that ingestion of a carbohydrate + protein beverage will lead to significant improvements in cycling time-trial performance relative to placebo and carbohydrate alone. Thirteen cyclists completed 120 min of constant-load ergometer cycling. Thereafter, participants performed a time-trial in which they completed a set amount of work (7 kJ kg(-1)) as quickly as possible. Participants completed four experimental trials, the first for familiarization and then three randomized, double-blind treatments consisting of a placebo, carbohydrate, and carbohydrate + protein. Participants received 250 ml of beverage every 15 min during the constant-load ride. Time-trial performance for carbohydrate (37.1 min, s = 3.8) was significantly (P < 0.05) faster than placebo (39.7 min, s = 4.6). Time-trial performance for carbohydrate + protein (38.8 min, s = 5.5) was not significantly different from either placebo or carbohydrate. Ingestion of a carbohydrate beverage during two hours of constant-load cycling significantly enhanced subsequent time-trial performance compared with placebo. The carbohydrate + protein beverage provided no additional performance benefit.  相似文献