Profile of isokinetic eccentric-to-concentric strength ratios of shoulder rotator muscles in elite female team handball players

Abstract

The purpose of this study was to establish the isokinetic profile of shoulder rotator muscles strength in female handball players. Twenty-seven handball players performed concentric and eccentric strength tests of both dominant and non-dominant upper limbs on an isokinetic dynamometer. Internal and external rotator muscles peak torque was assessed at 1.05, 3.14, and 5.23 rad · s⁻¹ in concentric mode and at 3.14 and 5.23 rad · s⁻¹ in eccentric mode. Concentric balance ratio and functional ratio were obtained. Bi-lateral deficiency was compared. Concentric strength for internal and external rotation was significantly greater for the dominant than for the non-dominant limb for all speeds (P ≤ 0.0001). For eccentric actions, internal rotator muscles were stronger in the dominant than the non-dominant limb (P ≤ 0.0001) at both speeds. Concentric balance and functional balance ratios did not differ between sides at 3.14 rad · s⁻¹ (P = 0.1631), but at 5.23 rad · s⁻¹ the functional balance ratio in the dominant limb was lower than for the non-dominant limb (P = 0.0500). Although the dominant side was stronger than the non-dominant side, balance concentric ratios remained the same, with only the functional strength ratio different at 5.23 rad · s⁻¹. Our results suggest that concentric strength exercises be used for internal and external rotators on the non-dominant side, and functional exercise that improves eccentric rotation strength for prevention programmes.

Keywords:

• Muscle strength dynamometer
• shoulder joint
• muscle weakness
• athletic injuries

Acknowledgements

We are grateful to the Directors of the Brazilian Confederation of Handball. We also would like to thank all the athletes who volunteered their time to participate in the study.

Marília dos S. Andrade received a fellowship from the Fundação de Amparo à Pesquisa do Estado de São Paulo-FAPESP (grant no. 07/59686-8).

Claudio A. B. de Lira received a fellowship from the Coordenação de Aperfeiçoamento de Pessoal de Ensino Superior – CAPES/Brazil.

The study was partially supported by the Studies and Projects Funding Body (Financiadora de Estudos e Projetos) - Brazilian Science and Technology Ministry (FINEP-MCT-Brazil) and the Brazilian Sports Ministry-CENESP.