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91.
The purpose was to evaluate the traditional method, of visually focusing on the ball, in comparison to focusing on the hole, during the putting stroke. The study design consisted of a pretest, a 4-week practice period, and a posttest. Participants (n = 31, handicap: 18.7 ± 10.4) practised using only one of the two gaze techniques. Testing consisted of having all participants putt using both gaze techniques from both a 1.22 m and a 4 m distance. Five putts were executed for each gaze technique/putt length combination for a total of 20 putts in each testing session per participant. The kinematics of every putting stroke executed during testing (1240 strokes) were captured using a TOMI? system. There was a significant improvement in putting success for both groups following practice (P = 0.001). Practising while visually focusing on the hole, resulted in a statistically significant reduction in putter speed variability in comparison to practising while visually focusing on the ball (P = 0.017). Visually focusing on the hole did not meaningfully (nor statistically) affect the quality of impact as assessed by the variability in face angle, stroke path, and impact spot at the precise moment the putter head contacted the ball.  相似文献   
92.
In this study, we evaluated the peak torque, functional torque ratios, and torque curve profile of the shoulder rotators in overhead athletes with impingement symptoms so as to examine possible alterations in response to sports training and shoulder pain. Twenty-one overhead athletes with impingement symptoms were compared with 25 overhead athletes and 21 non-athletes, none of whom were symptomatic for impingement. The participants performed five maximal isokinetic concentric and eccentric contractions of medial and lateral shoulder rotations at 1.57 rad · s(-1) and 3.14 rad · s(-1). Isokinetic peak torque was used to calculate the eccentric lateral rotation-to-concentric medial rotation and the eccentric medial rotation-to-concentric lateral rotation ratios. An analysis of the torque curve profiles was also carried out. The eccentric lateral rotation-to-concentric medial rotation torque ratio of asymptomatic athletes was lower than that of non-athletes at both test velocities. The concentric medial rotation isokinetic peak torque of the asymptomatic athletes, at 3.14 rad · s(-1), was greater than that of the non-athletes, and the peak appeared to occur earlier in the movement for athletes than non-athletes. These findings suggest that there may be adaptations to shoulder function in response to throwing practice. The eccentric medial rotation-to-concentric lateral rotation torque ratio was altered neither by the practice of university-level overhead sports nor impingement symptoms.  相似文献   
93.
Numerous variables influence burnout, one of which is leader-member exchange. The present study was conducted to determine whether leader-member exchange quality affects burnout in professional footballers. The study used the Leader-Member Exchange-7 scale developed by Scandura and Graen ( 1984 ) to measure leader (coach)-member (player) exchange and Pines's ( 2005 ) abbreviated version of the burnout scale developed by Pines and Aronson ( 1988 ) to measure burnout. The data were obtained from the professional players (N = 107) of six football clubs in the Turkish Secondary Football League in western Turkey. The results demonstrated that quality of leader-member exchange significantly and inversely influenced burnout of professional footballers. The study also evaluated quality of leader-member exchange in terms of three strengths of relationship (low, fair, and high) between the coach and players. Contrary to expectations, the results revealed significant differences in burnout when comparing low versus fair quality and low versus high quality, while no significant difference in burnout was observed between fair and high quality.  相似文献   
94.
The effects of switching focusing strategies on complex motor skill learning were investigated using a dart-throwing task. Participants were screened for reinvestment of conscious processing by completing the Reinvestment Scale (RS) of Masters, Polman, and Hammond (1993). After an initial baseline phase, two focusing strategies were described. Low and high reinvestors were then asked which of the strategies was used during baseline. Regardless of preference, they were requested to change focus. Novice dart-players used either a nonpreferred internal focus (EI), in which they were asked to concentrate on movements of their body, or a nonpreferred external focus (JE), in which they were asked to focus on the effects of their movements. This procedure produced two separate groups, El and 1E. Those scoring low and high on the RS were separated, thus producingfourgroups. Participants in the El high group were the least successful. These results support the findings of earlier studies suggesting that switching to an El is detrimental. Additionally, it appears that high reinvestors switching from a preferred 1E to a nonpreferred El are the most susceptible to unsuccessful performance.  相似文献   
95.
Non-exercise equations developed from self-reported physical activity can estimate maximal oxygen uptake (VO(2)max) as well as submaximal exercise testing. The International Physical Activity Questionnaire (IPAQ) is the most widely used and validated self-report measure of physical activity. This study aimed to develop and test a VO(2)max estimation equation derived from the IPAQ-Short Form (IPAQ-S). College-aged males and females (n = 80) completed the IPAQ-S and performed a maximal exercise test. The estimation equation was created with multivariate regression in a gender-balanced subsample of participants, equally representing five levels of fitness (n = 50) and validated in the remaining participants (n = 30). The resulting equation explained 43% of the variance in measured VO(2)max (SEE = 5.45 ml·kg(-1)·min(-1)). Estimated VO(2)max for 87% of individuals fell within acceptable limits of error observed with submaximal exercise testing (20% error). The IPAQ-S can be used to successfully estimate VO(2)max as well as submaximal exercise tests. Development of other population-specific estimation equations is warranted.  相似文献   
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97.
尽管宇宙已不如往昔那样活跃,但它仍然在以令人叹服的步伐形成恒星并打造黑洞。  相似文献   
98.
One hundred five participants from a random sample of elementary and middle school children completed measures of reading achievement and cognitive abilities presumed, based on a synthesis of current dyslexia research, to underlie reading. Factor analyses of these cognitive variables (including auditory processing, phonological awareness, short-term auditory memory, visual memory, rapid automatized naming, and visual processing speed) produced three empirically and theoretically derived factors (auditory processing, visual processing/speed, and memory), each of which contributed to the prediction of reading and spelling skills. Factor scores from the three factors combined predicted 85% of the variance associated with letter/sight word naming, 70% of the variance associated with reading comprehension, 73% for spelling, and 61% for phonetic decoding. The auditory processing factor was the strongest predictor, accounting for 27% to 43% of the variance across the different achievement areas. The results provide practitioner and researcher with theoretical and empirical support for the inclusion of measures of the three factors, in addition to specific measures of reading achievement, in a standardized assessment of dyslexia. Guidelines for a thorough, research-based assessment are provided.  相似文献   
99.
Dimensions and patterns of parenting were examined in a sample of 193 low-income African American single mothers with preschool-age children. Factor analyses yielded three dimensions: Aggravation, Nurturance, and Cognitive Stimulation. Cluster analysis yielded four patterns of parenting: Aggravated but Nurturant; Cognitively Stimulating; Patient and Nurturant; and Low Nurturance. Discriminant function analysis was used to predict membership in each of the four parenting clusters. Two composite functions emerged, the first representing maternal well-being (locus of control, depressive symptoms), the second representing sociodemographic characteristics (maternal education, duration on welfare, age at first birth), accounting for 93% of between-groups variability. Children's scores on measures of cognitive school readiness and personal maturity were significantly related to parenting pattern, even after controlling for significant predictors of parenting pattern; children's verbal ability was no longer related to parenting pattern once significant maternal characteristics were controlled. Findings are discussed in terms of contributions to the literature on parenting and in terms of implications for welfare policy and programs.  相似文献   
100.
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