Force transducer system for measurement of ice hockey skating force

The purpose of this study was to develop a portable force measurement system for ice hockey skating. The system consisted of three strain gauge pairs affixed to an ice hockey skate’s blade holder with wire leads connected to a microprocessor controlled data acquisition device carried in a backpack worn by the skater. The configuration of the strain gauges simultaneously determined the vertical and medial–lateral force components experienced by the blade holder with a resolution accuracy of 1.9 N and a coefficient of variation of 9.2%. On-ice testing of this system with subjects performing forward start, acceleration, and constant velocity skating permitted unencumbered, natural movement and demonstrated clear, unambiguous signal responses, high trial-to-trial repeatability, and easy data retrieval. The practicality and accuracy of this testing approach have many applications, such as a quantitative tool for skating force assessment to aid athletes and coaches, as well as providing the means to examine other skill-specific dynamics.     

Where, when, and why young athletes use imagery: an examination of developmental differences

The purpose of this study was to investigate young athletes' imagery use from a developmental perspective. The participants were 110 male and female athletes competing in both team and individual sports. They represented four different age cohorts (i.e., 7-8, 9-10, 11-12, and 13-14 years). Sixteen focus groups, two for each age category and gender, were used as the method of data collection. The findings indicated "where," "when, " and "why" young athletes use imagery and how imagery use changes as children move from early childhood through to early adolescence. Overall, results revealed that all age cohorts reported using imagery in both training and competition and for both cognitive and motivational purposes. The present research also found support for studying imagery use by young athletes from a developmental perspective.     

Differences in activation patterns between eccentric and concentric quadriceps contractions.

Previous studies analysing electromyograms (EMGs) from indwelling electrodes have indicated that fast-twitch motor units are selectively recruited for low-intensity eccentric contractions. The aim of this study was to compare the frequency content of surface EMGs from quadriceps muscles during eccentric and concentric contractions at various contraction intensities. Electromyograms were recorded from the rectus femoris, vastus lateralis and vastus medialis muscles of 10 men during isokinetic (1.05 rad x s(-1)) eccentric and concentric knee extension contractions at 25%, 50%, 75% and 100% of maximal voluntary contraction (MVC) for each contraction mode. Additionally, isometric contractions (70 degrees) were performed at each intensity. The mean frequency and root mean square (RMS) of the surface EMG were computed. Mean frequency was higher for eccentric than concentric contractions at 25% (P < 0.01), 50% (P < 0.01) and 75% (P < 0.05) but not at 100% MVC. It increased with increasing contraction intensity for isometric (P < 0.001) and concentric (P < 0.01) contractions but not for eccentric contractions (P = 0.27). The EMG amplitude (RMS) increased with increasing contraction intensity similarly in each contraction mode (P < 0.0001). Higher mean frequencies for eccentric than concentric contractions at submaximal contraction intensities is consistent with more fast-twitch motor units being active during eccentric contractions.     

Using the Ecosystemic Approach to Change Chronic Problem Behaviour in Primary Schools

This paper describes a small‐scale study of what the authors describe as the ecosystemic approach to changing chronic problem behaviour. The study was undertaken with a group of twelve Leicestershire primary teachers. The technique is briefly described and then teachers' responses to it and its effectiveness are discussed. Four case study examples are presented and finally its potential is considered. Although in this case the work was undertaken with primary teachers, this is an approach which could also be useful at secondary level.     

Serials management: integration and enhancement through reorganization

It is broadly acknowledged that effective serials management supports and requires a close link between the staff in technical and public services. More recently, new technological opportunities combined with changes in library organization and administration have greatly facilitated this linkage. The nature and structure of a library’s organization can aid in and benefit from this connectedness. Departments in the University of Louisville’s public and technical services areas began a cooperative effort to maintain serials records in the online catalog in the early 1990s. With reorganization in the late 1990s, a new team structure emerged which further facilitated this effort. In return, this cooperation and the tools that it has created support the teams in a new user-centered approach to serials management.