Decrease in neuromuscular control about the knee with maturation in female athletes.
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.
Hewett
Timothy E
TE
Cincinnati Children's Sports Medicine Biodynamics Center, 3333 Burnet Avenue, MLC 10001, Cincinnati, OH 45229-3039, USA. tim.hewett@cchmc.org
Myer
Gregory D
GD
Ford
Kevin R
KR
D000293:Adolescent; D000367:Age Factors; D016118:Anterior Cruciate Ligament / Q000502:physiology*; D001696:Biomechanical Phenomena; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000254:growth & development* / Q000502:physiology; D008297:Male; D018482:Muscle, Skeletal / Q000254:growth & development* / Q000502:physiology; D017933:Peripheral Nervous System / Q000254:growth & development* / Q000502:physiology; D011446:Prospective Studies; D012727:Sex Characteristics; D013177:Sports / Q000502:physiology*