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Functional eccentric-concentric ratio of knee extensors and flexors in pre-pubertal children, teenagers and adult males and females.
Int J Sports Med. 2007 Sep; 28(9):768-72.IJ

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 x s (-1) and 3.14 rad x 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 ECC (KF)/CON (KE) with higher ratios at 3.14 compared to 0.52 rad x s (-1). Females' CON (KF)/ECC (KE) was significantly lower than males at both velocities. Adults demonstrated significantly lower CON (KF)/ECC (KE) than the teenagers at 0.52 rad x s (-1) and lower than the prepubertal and teenager groups at 3.14 rad x s (-1). However, for ECC (KF)/CON (KE) at 3.14 rad x 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 CON (KF)/ECC (KE) 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 CON (KF)/ECC (KE) ratio in females is a product of lower concentric torque as opposed to high eccentric torque producing capability as previously thought.

Authors+Show Affiliations

Faculty of Sport, Health and Social Care, University of Gloucestershire, Gloucester, United Kingdom. mdestecroix@glos.ac.ukNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

17497581

Citation

De Ste Croix, M, et al. "Functional Eccentric-concentric Ratio of Knee Extensors and Flexors in Pre-pubertal Children, Teenagers and Adult Males and Females." International Journal of Sports Medicine, vol. 28, no. 9, 2007, pp. 768-72.
De Ste Croix M, Deighan M, Armstrong N. Functional eccentric-concentric ratio of knee extensors and flexors in pre-pubertal children, teenagers and adult males and females. Int J Sports Med. 2007;28(9):768-72.
De Ste Croix, M., Deighan, M., & Armstrong, N. (2007). Functional eccentric-concentric ratio of knee extensors and flexors in pre-pubertal children, teenagers and adult males and females. International Journal of Sports Medicine, 28(9), 768-72.
De Ste Croix M, Deighan M, Armstrong N. Functional Eccentric-concentric Ratio of Knee Extensors and Flexors in Pre-pubertal Children, Teenagers and Adult Males and Females. Int J Sports Med. 2007;28(9):768-72. PubMed PMID: 17497581.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Functional eccentric-concentric ratio of knee extensors and flexors in pre-pubertal children, teenagers and adult males and females. AU - De Ste Croix,M, AU - Deighan,M, AU - Armstrong,N, Y1 - 2007/05/11/ PY - 2007/5/15/pubmed PY - 2007/12/7/medline PY - 2007/5/15/entrez SP - 768 EP - 72 JF - International journal of sports medicine JO - Int J Sports Med VL - 28 IS - 9 N2 - 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 x s (-1) and 3.14 rad x 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 ECC (KF)/CON (KE) with higher ratios at 3.14 compared to 0.52 rad x s (-1). Females' CON (KF)/ECC (KE) was significantly lower than males at both velocities. Adults demonstrated significantly lower CON (KF)/ECC (KE) than the teenagers at 0.52 rad x s (-1) and lower than the prepubertal and teenager groups at 3.14 rad x s (-1). However, for ECC (KF)/CON (KE) at 3.14 rad x 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 CON (KF)/ECC (KE) 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 CON (KF)/ECC (KE) ratio in females is a product of lower concentric torque as opposed to high eccentric torque producing capability as previously thought. SN - 0172-4622 UR - https://www.unboundmedicine.com/medline/citation/17497581/Functional_eccentric_concentric_ratio_of_knee_extensors_and_flexors_in_pre_pubertal_children_teenagers_and_adult_males_and_females_ L2 - http://www.thieme-connect.com/DOI/DOI?10.1055/s-2007-964985 DB - PRIME DP - Unbound Medicine ER -