Background: Compared with male athletes, female athletes demonstrate increased dynamic valgus angulation of the knee during landing from a jump, although prior to maturation male and female athletes have similar forces and motions about the knee when they land from a jump. Our hypothesis was that musculoskeletal changes that accompany maturation result in poor neuromuscular control of the knee joint in female athletes.
Methods: One hundred and eighty-one middle-school and high-school soccer and basketball players-100 girls and eighty-one boys-participated in the study. Dynamic control of the knee joint was measured kinematically by assessing medial knee motion and the lower-extremity valgus angle and was measured kinetically by assessing knee joint torques; the values were then compared between female and male athletes according to maturational stage. Lower-extremity bone length was measured with three-dimensional kinematic analysis.
Results: Following the onset of maturation, the female athletes landed with greater total medial motion of the knees and a greater maximum lower-extremity valgus angle than did the male athletes. The girls also demonstrated decreased flexor torques compared with the boys as well as a significant difference between the maximum valgus angles of their dominant and nondominant lower extremities after maturation.
Conclusions: After girls mature, they land from a jump differently than do boys, as measured kinematically and kinetically.