Do baseball pitchers improve mechanics after biomechanical evaluations?

The purpose of this study was to determine how often flaws in pitching mechanics identified from biomechanical analysis are corrected. The biomechanics of 46 baseball pitchers were evaluated twice, with an average of 12 months (range 2–48 months) between evaluations. Pitchers were healthy at the time of both evaluations, competing at the high school, college, minor league or Major League level. After warming up, each participant pitched 10 full-effort fastballs. Automated three-dimensional motion analysis was used to compute eight kinematic parameters which were compared with a database of elite professional pitchers. Flaws—defined as deviations from the elite range—were explained to each participant or coach after his initial evaluation. Data from the second evaluation revealed that 44% of all flaws had been corrected. Flaws at the instant of foot contact (stride length, front foot position, shoulder external rotation, shoulder abduction, elbow flexion) or slightly after foot contact (time between pelvis rotation and upper trunk rotation) seemed to be corrected more often than flaws near the time of ball release (knee extension and shoulder abduction). Future research may determine which level athletes or which training methods are most effective for correcting flaws.     

Multifaceted Evaluation Criteria of Digital Libraries in Academic Settings: Similarities and Differences From Different Stakeholders

Digital library (DL) evaluation is essential to the success and enhancement of DLs. However, there is a lack of research on the assessment of comprehensive evaluation criteria across multiple dimensions of DLs. In particular, limited research is available on criteria prioritization to determine which criteria are perceived important by different stakeholders. This study was conducted to compare similarities and differences in perceptions of the importance of different DL evaluation criteria by heterogeneous stakeholders in academic settings. Ninety subjects were recruited with 30 from each of the group representing DL scholars, DL librarians, and DL users. Subjects were instructed to fill in an in-depth survey consisting of 10 evaluation dimensions with 94 criteria. ANOVA and t-test were applied to examine the similarities and differences among the three groups. This study reveals consensus and divergence in perceptions of criteria importance among the three groups, and indicates an inherent tension among the stakeholders. Moreover, the differences identify gaps not only between user expectations and the DL practice but also between what's desirable and what's possible in the academic environment. The findings provide a comprehensive list of criteria to guide practical evaluation of DLs, and contribute to the narrowing of the identified gaps.     

Understanding pupils' hiding techniques in physical education

Previous research shows that some pupils find physical education (PE) demanding and difficult. Some pupils use strategies to avoid participation in PE when it is demanding and difficult. The present study aims to illuminate and describe strategies used by pupils to avoid negative self-perception in difficult situations and activities in PE classes. This behavior, called hiding techniques, arises out of the need to protect self-perception and save academic or social face in the PE subject. Interviews and focus groups have been used with six PE teachers in Norwegian primary and lower secondary school to illuminate hiding techniques. Ten former pupils have also been interviewed about their experience of PE classes in primary/lower secondary school and upper secondary school for the same purpose. The results show that hiding techniques are experienced and practised in many different ways, and that there is a wide range of causes behind hiding techniques. Pupils' hiding techniques are categorized into main types, and the causes underlying the hiding techniques are summarized. This study provides insight into educational challenges that need to be highlighted to help all pupils in school, not just those who complete the PE subject without any real problems, to realize an important aim of the subject and to experience the joy of movement and lasting physical activity. It also highlights hiding techniques that are sophisticated, clever and deliberate actions pupils use to take control over the social setting in PE through the covert act of resistance rather than passively allowing the oppressive social setting to overpower them.     

Kinematic and kinetic differences between left-and right-handed professional baseball pitchers

While 10% of the general population is left-handed, 27% of professional baseball pitchers are left-handed. Biomechanical differences between left- and right-handed college pitchers have been previously reported, but these differences have yet to be examined at the professional level. Therefore, the purpose of this study was to compare pitching biomechanics between left- and right-handed professional pitchers. It was hypothesised that there would be significant kinematic and kinetic differences between these two groups. Pitching biomechanics were collected on 96 left-handed pitchers and a group of 96 right-handed pitchers matched for age, height, mass and ball velocity. Student t-tests were used to identify kinematic and kinetic differences (p < 0.05). Of the 31 variables tested, only four were found to be significantly different between the groups. Landing position of the stride foot, trunk separation at foot contact, maximum shoulder external rotation and trunk forward tilt at ball release were all significantly greater in right-handed pitchers. The magnitude of the statistical differences found were small and not consistent with differences in the two previous, smaller studies. Thus, the differences found may be of minimal practical significance and mechanics can be taught the same to all pitchers, regardless of throwing hand.     

L'education professionnelle des femmes et le conflit des roles

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