Just came back from a seminar about ACL knee injuries/prevention in girls, given by Laura Ramus, P.T., ATC who is head trainer for the WNBA Detroit “shock” team who won 3 championships. The statistics are daunting. In the U.S. girls suffer 30,000 ACL injuries per year. Girls are 4-6X more likely to suffer ACL injuries than boys.
Here are some facts:
The ACL (anterior cruciate ligament) is a ligament in the knee that stabilizes the knee on physical activity. So it helps us stop suddenly, move side-to-side quickly and land straight down when we jump. This ligament should be the last safeguard we use when doing these activities because our muscles should be working together to be our main knee support. But…
In girls…we tend to use our ACL much more because girls primarily use their quadriceps (thigh) for running, jumping, and moving side to side, whereas boys use their hamstrings. Hamstrings protect the ACL.
It takes girls 3/10ths of a second longer to contract their hamstrings than boys. That doesn’t sound slow, but it is if you consider it takes 1/10th of a second to jump.
Girls don’t get ACL injuries until after puberty because estrogen makes tissues/ligaments more elastic and looser, so they don’t contract as well.
Pelvic size is different for girls because their hips are wider which causes their knees to turn in. This is called the Q-angle.
Girls have more lumbar lordosis (more of a curve in the lower back) which causes their knees to hyperextend and turn inward.
Shoes make a difference! Flat feet or pronation causes strain on the ACL and leads to injuries unless it’s balanced with orthodics or good sneakers that address this problem. Also, shoes should bend at the toe box (end of the toes), not at the mid-foot (near the arch).
It’s not the knees that are the problem. The problem is with the feet/ankles or the pelvis.
1) Strengthening the gluteus maximus (butt muscles) and hamstrings which are commonly weak in girls.
2) Practice balance and proprioception. Balance and being aware of how your body is in alignment is the “glue” that holds the bones, ligaments and muscles together. Squats are a great exercise for this.
3) Work on speed of contracting the muscles. Try to do 20 squats in 20 seconds with GOOD form. It’s harder then you think!
4) These prevention exercises should be started at age 9 for girls. For all you women athletes, start these exercises now! Hopefully coaches will start incorporating these exercises in the many sports girls play.
Find out more at www.girlscanjump.com.