Boys demonstrate greater knee frontal moments than girls during the impact phase of cutting maneuvers, despite age-related increases in girls

Abstract

Purpose Anterior cruciate ligament (ACL) injury rate is low among children, but increases during adolescence, especially in girls. Increases in the knee valgus moment within 70 ms of contact with the ground (KFM0-70) may explain the sex-specific increase in the risk of ACL injury. The purpose of the study was to investigate sex-dependent changes in the KFM0-70 from pre-adolescence to adolescence during a cutting maneuver (CM). Methods Kinematic and kinetic data during the CM task, performed before and after physical exertion, were recorded using a motion capture system and a force plate. A total of 293 team handball and soccer players, aged 9–12 years, were recruited. A number of those who continued sports participation (n = 103) returned five years later to repeat the test procedure. Three mixed-model analysis of variance (ANOVA) for repeated measures tests were used to determine the effects of sex and age period on the KFM0-70 (1: with no adjustment, 2: adjusted for repeated measurements, and 3: additionally adjusted with hip and knee joint frontal plane kinematics). Results Boys had significantly higher KFM0-70 than girls at both age periods (p < 0.01 for all models). Girls, not boys, demonstrated significantly increased KFM0-70 from pre-adolescence to adolescence. Importantly, this was fully explained by kinematic variables. Conclusion Although the marked increase in KFM0-70 seen in girls may play a role in their risk of ACL rupture, the higher values demonstrated by boys during CM reflect the complexity of multifactorial biomechanical risk factor analysis. The role of kinematics in mediating the KFM0-70 provides means for modification of this risk factor, but as boys had higher joint moments, continued investigation into sex-dependent biomechanical risk factors is warranted. Level of evidence II.

Differences in Biomechanical Determinants of ACL Injury Risk in Change of Direction Tasks Between Males and Females: A Systematic Review and Meta-Analysis

“…Considering the relationship between increased knee abduction and limited knee flexion with ACL strain [ 28 , 30 , 96 ], this observation may partially explain some of the disproportionately greater ACL injury incidence between females and males [ 19 , 97 , 98 ]. This finding also aligns with observational studies identifying limited knee flexion and dynamic knee valgus to be apparent features of non-contact ACL injury [ 9 – 11 ], particularly in females [ 10 , 99 – 101 ].…”

“…Such practice is questionable due to the confounding effects of task [ 50 , 90 ], which has been previously identified as biomechanically discrete in relation to multiplanar knee joint loads and braking characteristics [ 103 ]. Furthermore, effects of maturation [ 51 , 101 ], fatigue [ 60 ] and externally applied bracing [ 59 ] provide another layer of measurement variability that could skew the interpretation of sex differences in COD mechanics should the data be pooled prior to performing sex comparisons. The current findings of this analysis suggest that more carefully controlled research is required examining sex differences in COD biomechanics.…”