Dynamic Knee Valgus Prevalence in Children and Its Association with Pain Intensity, Foot Mobility, and Sex- A Cross-sectional Study

Introduction: Knee pain can impact the performance of activities and sports participation in children. Dynamic knee valgus is a movement pattern commonly related to health conditions that may be associated with sex and foot kinematics in children.

Objective: To assess the prevalence of dynamic knee valgus and its relationship with foot mobility, sex, and knee pain in children.

Method: A cross-sectional observational study was carried out with 144 children (10-18 years old). The pain level was investigated using the Visual Analog Pain Scale and categorized into no pain/minor pain (≤2 cm), moderate pain (3-4,9 cm), and severe pain (≥5.0 cm). Foot mobility was assessed using the adapted navicular drop test and categorized into poor/adequate foot mobility (0.0 cm-0.9 cm) and greater foot mobility (≥1.0 cm). The dynamic knee valgus presence was checked using the step-down test. The association analysis was performed using simple tabulation considering the cluster effect. The Prevalence Ratios and the respective confidence intervals (95%) were estimated from Multiple Poisson Regression with robust variance. A significance level of 5% was adopted.

Results: The dynamic knee valgus prevalence was 26.3% and 26.9% in the right and left lower limbs, respectively. Females presented greater dynamic knee valgus frequency in the left lower limb than males. The dynamic knee valgus presence in males was associated with foot mobility in right ( = 0.001) (Prevalence Ratio: 9.33 Confidence Interval: 2.93-29.72) and left lower limbs ( = 0.003) (Prevalence Ratio: 6.25 Confidence Interval: 1.7-22.62).

Conclusion: Male and female children showed different relationships of the analyzed factors, suggesting that characteristics related to sex may impact the aspects linked to dynamic knee in children.