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7th EFSMA – European Congress of Sports Medicine, 3rd Central European Congress of Physical Medicine and Rehabilitation, Annual Assembly of the German and the Austrian Society of Physical Medicine and Rehabilitation

Austrian Society of Physical Medicine and Rehabilitation

26.-29.10.2011, Salzburg, Österreich

Strength profile of external and internal shoulder rotators in elite volleyball players

Meeting Abstract

  • corresponding author presenting/speaker Vedran Hadzic - University in Ljubljana, Faculty of sport, Dept. of Sports Medicine, Ljubljana, Slovenia
  • author Tine Sattler - University in Ljubljana, Faculty of sport, Dept. of Volleyball, Ljubljana, Slovenia
  • author Suza Pustivsek - University in Ljubljana, Faculty of sport, Ljubljana, Slovenia
  • author Edvin Dervisevic - University in Ljubljana, Faculty of sport, Dept. of Sports Medicine, Ljubljana, Slovenia

7th EFSMA – European Congress of Sports Medicine, 3rd Central European Congress of Physical Medicine and Rehabilitation. Salzburg, 26.-29.10.2011. Düsseldorf: German Medical Science GMS Publishing House; 2011. Doc11esm102

DOI: 10.3205/11esm102, URN: urn:nbn:de:0183-11esm1024

Veröffentlicht: 24. Oktober 2011

© 2011 Hadzic et al.
Dieser Artikel ist ein Open Access-Artikel und steht unter den Creative Commons Lizenzbedingungen (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.de). Er darf vervielfältigt, verbreitet und öffentlich zugänglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

Objective: The objective of our study was to establish a baseline strength profile of shoulder external and internal rotators in elite volleyball players, where chronic shoulder injuries represent a significant health problem. Our other goals were to evaluate the side dominance effect for those muscle groups and to explore the possible strength differences between different playing positions, age groups and levels of play.

Material/Methods: A sample of 118 male volleyball players from Slovenian Division 1 and 2 was tested using the Techno Gym REV900 isokinetic dynamometer. Testing was performed in short range of motion (30°) at the angular velocity of 90°/s in the concentric mode of contraction for both muscle groups. The main outcome measure was peak torque (Newton meters – Nm) of shoulder internal and external rotators normalized for body weight (Nm/kg). A repeated measure ANOVA was used to evaluate the side dominance effect, while multivariate ANOVA was used to evalute the differences in strength across different playing positions, age groups and levels of play.

Results: The results are depicted in Figure 1 [Fig. 1] that shows peak torque to body weight normalized values for external and internal rotators and above are repeated measures ANOVA findings for a factor side dominance. We may conclude that there are important bilateral strength differences in relation to the side dominance effect. This effect is much stronger for internal than for external rotators as indicated by large difference in F values. Multivariate ANOVA has shown that there are no significant strength differences between different playing positions (F=0.72, p=0.78), age groups (F=1.18, p=0.32) or levels of play (F=0.99, p=0.41).

Conclusion: Our study has shown that there is a significant difference in concentric strength of shoulder internal and external rotators in elite volleyball players between dominant and non-dominant arm side. This effects is approximately 10 times stronger for internal than external rotators. This finding can be explained by the fact that concentric strength of internal rotators is crucial for spiking and serving activities, but this is not followed by concomitant increase in the strength of antagonist muscle group – the external rotators. This could of course predispose volleyball players for shoulder injury. Furthermore, we may also conclude that there are no systematic differences among different levels of play, age groups or playing positions. We believe that our findings give an important data on shoulder external and internal rotators strength that will be of great value and interest for clinicians and coaches as reference values for rehabilitation and/or training purposes.


References

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