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Author Dario G. Liebermann; Murray E. Maitland; Larry Katz openurl 
  Title Lower-limb extension power: How well does it predict short distance speed skating performance? Type Journal Article
  Year 2002 Publication Isokinetics and Exercise Science Abbreviated Journal  
  Volume 10 Issue 2 Pages 87-95  
  Keywords  
  Abstract This study was aimed to explore the relationship between lower limb extension power measured by isokinetic knee extensions (IK) and vertical jumps performed on a force plate (VJ) and speed skating (SS) sprint power measured by a laser device.

Methods: Twenty elite short- and long-track speed skaters performed 100 m sprints followed by VJ and IK trials. Power-time curves were calculated off-line. Pearson correlation coefficients were used to determine the degree of association between the variables.

Results: SS sprint power correlates strongly with VJ power (r=0.870; p<0.001) while IK power showed a weaker but significant correlation to both (r=0.707 and r=0.706, respectively; p<0.01). As expected, SS times at 15 m and 100 m were inversely associated with SS sprint power (r=-0.818 and r=-0.909; p<0.001) and VJ power (r=-0.730 and r=-0.763; p<0.001), and to a lesser degree with IK power (r=-0.602; r=-0.618; p<0.01).

Conclusion: The analyses differentiate between methods of estimating power in speed skaters, and show a strong relationship between initial SS performance and muscular power. Given that 100 m split times strongly relate to final 500 m results (r=0.972; p<0.001, N=332), it is reasonable to believe that an initial power and a stable peak speed before the first curve may lead to achieving the winning edge in short SS events. A finding of particular interest is that isokinetic power results are correlated significantly with the practical outcomes of the performance in spite of the high specificity of the isokinetic testing method.
 
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  Call Number Serial 62  
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Author Dario G. Liebermann; Larry Katz openurl 
  Title On the assessment of lower-limb power capability Type Journal Article
  Year 2003 Publication Isokinetics and Exercise Science Abbreviated Journal  
  Volume 11 Issue 2 Pages 87-94  
  Keywords  
  Abstract Purpose: This study assessed the reliability and validity of different methods used to estimate lower-limb muscular power capability based on mechanical variables. For this purpose, vertical jumping was compared with isokinetic knee extensions and with power tests used by practitioners.

Methods: Four groups of subjects (N = 106) were tested in different conditions. Group-I performed countermovement vertical jumps (CMJ) on a force plate followed by left and right knee extensions on an isokinetic device at 120, 180 and 240 deg&#65533;s-1. Group-II performed CMJ trials followed by 20-m sprints, hand-reach jumps and 1RM leg-press testing. Group-III carried out squat jumps (SJ) in addition to CMJ trials. Finally, Group-IV performed the CMJ test and was retested twice after a short inter-session interval (1–4 days) and after a long one (4.5–5 months). The Pearson correlation was used to assess the validity and reliability of CMJ (p &#8804; 0.01, ).

Results: Mean peak power during CMJ was correlated with sprint time (r = -0.882
) and leg-press 1 RM (r = 0.797), but less with peak hand-reach height (r = 0.695; p &#8804; 0.05). Isokinetic knee extension power showed also a significant correlation with CMJ power, but its strength depended on the angular velocity (Isok-120 r = 0.702; Isok-180 r = 0.737; Isok-240 r = 0.599). Test-retests showed a strong correlation after a short interval (r = 0.915) and after a long one (r = 0.890). Using the SJ technique did not have any effect on reliability (r = 0.914**).

Conclusions: CMJ matches other methods used for testing lower-limb power capability. It is highly reliable and it allows a valid assessment of muscular power. Since CMJ is also simple and accurate to perform, it is the recommended method.
 
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  Call Number Serial 63  
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Author Dario G. Liebermann; Larry Katz; and Ruth Morey Sorrentino openurl 
  Title Experienced Coaches’ Attitudes Towards Science and Technology Type Journal Article
  Year 2005 Publication International Journal of Computer Science in Sport Abbreviated Journal  
  Volume 4 Issue 1 Pages 21-28  
  Keywords  
  Abstract In this study, the attitude of experienced coaches towards technologies and sport

sciences was assessed. A questionnaire was used to evaluate three areas: (1)

Attitudes towards technology and sport science in coaching, (2) Technology and

scientific knowledge in practice, and (3) Perceived importance of technology and

science in enhancing sport results. A group of 27 highly experienced coaches

completed the questionnaire. The questionnaire consisted of three parts, starting

with demographic information, followed by a series of 27 questions with answers

on a Likert scale ranging from strongly agree to strongly disagree, and finally,

coaches were requested to rank 14 well-defined ‘coaching goals’ from 1 (most

important) to 14 (least important). Results showed that top-level coaches rated

having a good relationship with the athletes’ as a major goal. Overall, members of

this group of experienced coaches seem to recognize the general importance of

sport sciences, and appear to be positive about the use of sport technologies, but

do not necessarily translate these positive attitudes into actual practice within

their competitive sport environments, even when they all use information

technology for other activities. According to these results, sport science

researchers and technology developers need to adapt their strategies. Coaching

education should encourage coaches to incorporate technologies as part of their

coaching routines. Developing innovative resources and incorporating them in

coaching education, as is done in some countries, may be a starting point.

However, placing the emphasis on educating successful coaches on the practical

use of technology and scientific knowledge is suggested as a short-term goal.

This may allow for a more immediate effect on the attitude and practice of less

senior coaches that tend to adopt methods and training routines through following

the personal example provided by top-level coaches.
 
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  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 66  
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