Prevention of anterior cruciate ligament injuries

Numerous studies have found that female athletes who participate in jumping and pivoting sports are four to six times more likely to sustain a knee ligament injury, such as anterior cruciate ligament (ACL) injury, than male athletes participating in the same sports [1-8]. A widening gender gap in the number of serious knee ligament injuries exists due to geometric growth in female athletic participation, coupled with the four- to sixfold higher injury rate. More than 50,000 serious knee injuries are projected to occur in female varsity intercollegiate and high school athletics each year [9, 10]. Most ACL injuries occur by noncontact mechanisms, often during landing from a jump or making a lateral pivot while running [2, 11]. Knee instability, due to ligament dominance (decreased medial-lateral neuromuscular control of the joint), quadriceps dominance (increased quadriceps recruitment and decreased hamstring recruitment and strength), and leg dominance (side-to-side differences in strength, flexibility, and coordination) are possible contributing factors to the increased incidence of knee injury in female athletes [5, 6]. In this review, dynamic neuromuscular analysis (DNA) training is defined, and a rationale is presented for correcting the neuromuscular imbalances that may result in dynamic knee instability during sports play. Dynamic neuromuscular training has been shown to increase knee stability and decrease knee injury rates in female athletes [5, 12.., 13.]. Preliminary research on athlete screening and injury prediction based on the three aforementioned imbalances also is presented with recommendations for developing screening protocols for the identification of high-risk athletes.