The energetics and benefit of an arm swing in submaximal and maximal vertical jump performance

The aims of this study were to investigate the energy build-up and dissipation mechanisms associated with using an arm swing in submaximal and maximal vertical jumping and to establish the energy benefit of this arm swing. Twenty adult males were asked to perform a series of submaximal and maximal vertical jumps while using an arm swing. Force, motion and electromyographic data were recorded during each performance and used to compute a range of kinematic and kinetic variables, including ankle, knee, hip, shoulder and elbow joint powers and work done. It was found that the energy benefit of using an arm swing appears to be closely related to the maximum kinetic energy of the arms during their downswing, and increases as jump height increases. As jump height increases, energy in the arms is built up by a greater range of motion at the shoulder and greater effort of the shoulder and elbow muscles but, as jump height approaches maximum, these sources are supplemented by energy supplied by the trunk due to its earlier extension in the movement. The kinetic energy developed by the arms is used to increase their potential energy at take-off but also to store and return energy from the lower limbs and to "pull" on the rest of the body. These latter two mechanisms become more important as jump height increases with the pull being the more important of the two. We conclude that an arm swing contributes to jump performance in submaximal as well as maximal jumping but the energy generation and dissipation sources change as performance approaches maximum.     

Influences and Experiences Affecting the Pro‐environmental Behaviour of Educators

This paper examines the relative importance of various categories of influence and formative life experiences on the development of environmental educators’ knowledge and concern for the environment. The authors analyse the ways in which the importance of influences may change through time or be affected by the subject's age. Conclusions are drawn and discussed, including the crucial role of the family and of childhood experiences outdoors in promoting the development of concern for the environment and pro‐environmental adult behaviour.     

Staff meetings,why have them?

Mary Louise Harbinger was the new director of Tiny Tots Day Care Center. She was feeling decidedly uncomfortable. Ten minutes before, her first staff meeting had begun. She now sat facing fifteen pairs of hostile, blank eyes placed on fifteen unsmiling, distrustful faces.Nora Palmer Gould is the director of Northen Dutchess Day Care Center, Inc., in Rhinebeck, N.Y.     

Value differences in foreign students

The Rokeach Value Survey was administered to four equivalent groups of students studying in London. It was hypothesized that a number of differences would occur between these groups based on their country of origin, respective affluence and traditional cultural values. Half of the values showed significant differences between groups with the British Control Group and the Europeans being most often more similar to each other than the other groups. The Africans were most different from the three other groups. These results were interpreted in terms of cultural and economic differences and related specifically to the literature of sojourner adjustment. Limitations of the research are also noted.     

Refinements Introduced in the Oddy Test Methodology

The ‘Oddy test’ is an accelerated corrosion test introduced in the 1970s at the British Museum to identify materials likely to emit volatile substances that could harm museum artefacts. It is carried out in many museums all around the world, but not always using the same methodology, which makes it difficult to compare and share test results between institutions. Refinements to the Oddy test methodology have been implemented at the British Museum over the last decade and the aim of this paper is to present these and promote consistency across institutions. The modifications introduced concern the method used to wash the glassware, the preparation of the metal coupons, and standard methods for preparing samples of liquid coatings, adhesives, and adhesive tapes. Finally, conducting Oddy tests is time consuming and measures employed at the British Museum to reduce the number of materials to be tested and streamline testing are described.