Citation

Sasaki S, Tsuda E, Yamamoto Y, Maeda S, Hayashi Y, Kimura Y, Sasaki E, Fujita Y, Takahashi I, Umeda T, Nakaji S, Ishibashi Y. J. Orthop. Sci. 2013; 18(5): 774-781.

Affiliation

Department of Orthopaedic Surgery, Hirosaki University Graduate School of Medicine, Zaifu-cho 5, Hirosaki, Aomori, 036-8562, Japan, shizuka@cc.hirosaki-u.ac.jp.

Copyright

(Copyright © 2013, Holtzbrinck Springer Nature Publishing Group)

DOI

10.1007/s00776-013-0420-3

PMID

23775465

Abstract

BACKGROUND: A discrepancy in the incidence of anterior cruciate ligament injury in males and females appears after puberty; however, little is known about changes that occur in control of the lower limbs during jump-landing in adolescents. METHODS: Twenty-five male and 29 female 5th grade students (age 10-11 years) participated at the beginning of study and were followed for 5 consecutive years. Control of the lower limbs during jump-landing was evaluated by use of a drop-jump test and 2-dimensional video analysis. The K/H ratio, which was determined by dividing the knee-separation distance by the hip-separation distance, was calculated for initial contact (IC) and for maximum knee flexion (MKF). RESULTS: In all grades female subjects had a significantly lower K/H ratio at both IC and MKF than male subjects. Although no statistically significant difference in K/H ratio between age categories was shown at either IC or MKF for male subjects, K/H ratio at IC and MKF decreased significantly between 5th grade and 9th grade for female subjects. CONCLUSION: This study suggests that adolescent females have a lower K/H ratio during jump-landing than male subjects of the same age, and that K/H ratio for females decreases with increasing age.

Language: en