Int J Sports Med 2007; 28(9): 768-772
DOI: 10.1055/s-2007-964985
Training & Testing

© Georg Thieme Verlag KG Stuttgart · New York

Functional Eccentric-Concentric Ratio of Knee Extensors and Flexors in Pre-Pubertal Children, Teenagers and Adult Males and Females

M. De Ste Croix1 , M. Deighan1 , N. Armstrong2
  • 1Faculty of Sport, Health and Social Care, University of Gloucestershire, Gloucester, United Kingdom
  • 2School of Sport and Health Sciences, University of Exeter, Exeter, United Kingdom
Further Information

Publication History

accepted after revision July 28, 2006

Publication Date:
11 May 2007 (online)

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Abstract

The purpose of this study was to examine the age and sex associated differences in the eccentric/concentric functional ratio for the knee. Isokinetic concentric and eccentric knee extension and flexion was measured at 0.52 rad · s-1 and 3.14 rad · s-1 in 121 subjects. Other than mass there were no significant age-by-sex interaction effects for all variables examined. A significant velocity-by-age group effect was demonstrated for ECCKF/CONKE with higher ratios at 3.14 compared to 0.52 rad · s-1. Females' CONKF/ECCKE was significantly lower than males at both velocities. Adults demonstrated significantly lower CONKF/ECCKE than the teenagers at 0.52 rad · s-1 and lower than the prepubertal and teenager groups at 3.14 rad · s-1. However, for ECCKF/CONKE at 3.14 rad · s-1, prepubertal ratios were significantly lower than teenagers and adults. The results of the current study suggest that functional rather than conventional ratio should be used when examining knee stability. During fast velocity movements, prepubertal children have a lower capacity for generating eccentric compared to concentric torque. The lower CONKF/ECCKE ratio in adults appears to be due to a greater ability to generate large eccentric torques at all slow and fast movement velocities. The lower CONKF/ECCKE ratio in females is a product of lower concentric torque as opposed to high eccentric torque producing capability as previously thought.

References

Dr. PhD Mark De Ste Croix

University of Gloucestershire
Faculty of Sport, Health and Social Care

GL2 9HW Gloucester

United Kingdom

Fax: + 44 14 52 87 66 48

Email: mdestecroix@glos.ac.uk