Comparison of kinematics in skilled and unskilled arms of the same recreational baseball players

We examined mechanisms of coordination that enable skilled recreational baseball players to make fast overarm throws with their skilled arm and which are absent or rudimentary in their unskilled arm. Arm segment angular kinematics in three dimensions at 1000 Hz were recorded with the search-coil technique from the arms of eight individuals who on one occasion threw with their skilled right arm and on another with their unskilled left arm. Compared with their unskilled arm, the skilled arm had: a larger angular deceleration of the upper arm in space in the forward horizontal direction; a larger shoulder internal rotation velocity at ball release (unskilled arms had a negative velocity); a period of elbow extension deceleration before ball release; and an increase in wrist velocity with an increase in ball speed. It is suggested that some of these differences in arm kinematics occur because of differences between the skilled and unskilled arms in their ability to control interaction torques (the passive torque at one joint due to motion at adjacent joints). It is proposed that one reason unskilled individuals cannot throw fast is that, unlike their skilled counterparts, they have not developed the coordination mechanisms to effectively exploit interaction torques.     

2008年的世界

2008年,世界会怎样?经济、军事、政治、环境等,无一不关系到整个世界的生存环境与发展.著名报纸<金融时报>近期推出了特别报道--2008年的世界,我们特意选取部分具有代表性的文章,其中对中国在未来世界的地位和作用也有所涉及,在此与大家一起分享.     

Book Reviews

Towards Electronic Journals: Realities for Scientists, Librarians and Publishers by Carol Tenopir and Donald W. King. Washington, DC: SLA Publishing, 2000 Science Editing and Information Management edited by Connie J. Manson. USA: Geoscience Information Society, 1999. Pp. 118. Paperback, $25.00. ISBN 0‐934485‐30‐5 Futurize Your Enterprise: Business Strategy in the Age of the E‐Customer by David Siegel. Chichester: Wiley, 1999. Hardback, £19.50, ISBN 0‐471‐357634 The Impact of Electronic Publishing on the Academic Community (the Wenner–Gren International Series, Volume 73) edited by I. Butterworth. London: Portland Press 1998, Pp. 191. Price £75. ISBN 1‐85578‐122‐0 University Library Spending on Books and Journals: A Major Concern by Peter Sowden. Available from CAPP at the Publishers Association (1 Kingsway, London WC2B 6XF)     

Report on accreditation learning sets in the West Midlands Region of the NHS

This article reports on the evaluation of the first year of a project, which utilized learning sets to support librarians undergoing the accreditation process, in the health libraries in the West Midlands region of the NHS. The West Midlands Health region is divided up into education consortia patches. Each group of patch librarians was allocated a local accreditation facilitator. The groups met regularly to discuss problems and progress relating to their library’s accreditation. The results of the evaluation suggest that this is a valuable approach to use. The recommendations state that regular, frequent meetings are needed. Extra training and guidance would help the facilitators to be more effective in their role.