The incidence rate per 100,000 person-years rose 2.5% annually for females and 2.2%
annually for males over 20 years.
The authors noted that other studies have attributed rising ACL tears to increases
in females and younger children participating in sports, greater clinician awareness
and improved diagnostics.
Females accounted for about 52% of the 3,303 injuries and outpaced males at younger
ages, although not at ages 17-18. The risk for females peaked at age 16 and for males
The higher rates of injury for females “are thought to be related factors such as
geometry of the intercondylar notch, and smaller size of ACL, as well as biomechanical
and neuromuscular factors such as higher quadriceps-to-hamstring ratio and landing
from a jump with less hip and knee flexion and more hip adduction leading to increased
dynamic knee valgus with greater knee abduction angles,” according to the study.
In 2014, the Academy released a clinical report aimed at helping pediatricians diagnose, treat and prevent ACL tears and suggested
neuromuscular training as a means of prevention.
“Neuromuscular training appears to reduce the risk of injury in adolescent female
athletes by 72%,” the AAP report states. “Prevention training that incorporates plyometric
and strengthening exercises, combined with feedback to athletes on proper technique,
appears to be most effective.”