Relationships Between Static Anatomical Structural Characteristics And Dynamic Knee Valgus During The Landing Phase Of A Drop Jump

Abstract

Lower extremity structural characteristics may influence dynamic knee motion during landing. PURPOSE To examine the relationships between static structural characteristics and dynamic valgus during drop jump landing. METHODS Twelve men and 13 women participated. Ten static structural measures were obtained from each subject: height, weight, Q-angle, pelvic width, femur length, tibia length, navicular drop, transverse plane thigh-foot angle, femoral torsion, and sagittal plane knee laxity. Subjects performed three bilateral drop jumps from 0.50 m onto a force plate (right foot) while right knee valgus angle was measured using an elgon (1000 Hz). Valgus angle at contact and maximum valgus during landing were the dependent variables. The five structural measures that were most highly correlated with each valgus measure were entered into regression models (α = 0.05) in order to predict the valgus variables. The regression procedures were completed for the overall group, men only, and women only. RESULTS For the group, Q-angle, height, thigh-foot angle, femur length, and pelvis width most highly correlated with maximum valgus (r-values: 0.43, −0.26, 0.24, 0.21, −0.18, respectively), but the prediction was not significant (R2 = 0.24, p = 0.34). Thigh-foot angle, Q-angle, tibia length, height, and navicular drop most highly correlated with valgus at contact (r-values: 0.37, 0.30, −0.30, −0.18, −0.16, respectively), but the prediction was not significant (R2 = 0.22, p = 0.41). For men, Q-angle, thigh-foot angle, height, tibia length, and navicular drop most highly correlated with maximum valgus (r-values: 0.68*, 0.61*, −0.45, −0.27, −0.19, respectively; *p<0.05), but the prediction was not significant (R2 = 0.72, p = 0.10). Q-angle, thighfoot angle, femur length, navicular drop, and height most highly correlated with valgus at contact (r-values: 0.72*, 0.46, 0.37, −0.23, −0.21, respectively; *p<0.05), but the prediction was not significant (R2 = 0.72, p = 0.10). For women, tibia length, femoral torsion, weight, Q-angle, and height most highly correlated with maximum valgus (r-values: −0.57*, −0.29, −0.27, 0.25, −0.17, respectively; *p<0.05), but the prediction was not significant (R2 = 0.64, p = 0.14). Tibia length, weight, height, Q-angle, and pelvis width most highly correlated with valgus at contact (r-values: −0.48, −0.48, −0.47, 0.34, −0.28, respectively), but the prediction was not significant (R2 = 0.60, p = 0.19). CONCLUSION Although the regression models did not significantly predict the valgus variables, individual structural characteristics may be positively and negatively related to dynamic valgus in men and women, respectively.