ACL Risk Reduction

There are many different mechanisms that cause ACL injuries.  It needs to be noted that 70% of all ACL injuries are non-contact.  This is that injury that you see where the athlete is all alone and the next thing you know, they are on the ground in pain.  They do something that they have done many times before, but this time caused the injury.  Below is an example of a non-contact ACL injury.  Look at the athletes left knee.

 Female athletes are around 6 times more likely to tear their ACL than a male athlete.  Another way to look at that is that one out of every ten female college athletes will tear their ACL every year.  Why does this happen?



Risk Factors for ACL Injury

Anatomical :
- Femoral notch size
- Q-angle.  This is the “knock kneed” individual.  Also known as valgus alignment.

Biomechanical :
- Females land in a more upright position compared to males.
- Females utilize their quadriceps in landing instead of the hamstrings to help absorb the forces of landing.
- Females take longer to recruit the muscles to fire and stabilize the knee compared to males.

Hormonal :
- There is ongoing debate and research as to the role that the sex specific hormones play in the role of ACL injuries.
- Females tend to be more lax or loose at their joints compared to males.

Environmental :
- Shoe to surface interface
- Sport
- Weather conditions
- Year round play
These are just a few of the things that can contribute to a person injuring their knee.  Research is ongoing in this area.

ACL Injury Prevention

Remember that roughly 200,000 ACL injuries occur every year.  A good prevention program is the best way to try and prevent from having reconstructive surgery or another type of knee injury.  It should be noted that there is no sure fire way to prevent all injuries.

The prevention program should include the following things:

- Time off from sport(s).  Everyone needs time away.  The body will eventually break down if not given sufficient time to recover.  The minimum amount of time should be at least 6 weeks.

- Total body strengthening program.  This includes exercises and activities to address any deficits in strength or flexibility that the athlete may have.

- Neuromuscular training.  This is a very important aspect of ACL injury prevention.  Athletes and especially females need to learn how to land in a way that does not set them up for knee ligament injury. 

Dr. Lowe and his staff utilize and recommend a program known as Sportsmetrics™.  This program was created at the Cincinnati Sportsmedicine Research and Education Foundation.  This program has over 10 years of research showing a decrease in ACL injuries in females to males from 6:1down to 2:1.  To get the most benefit from this program, it needs to be done 3 times a week for 6 weeks.  The jumps become progressively more difficult in an effort to prepare the body for the demands of their sport.  Not only has the program shown to prevent injuries, but it has also shown to increase the athletes vertical jump height.

In this picture, you see an untrained athlete performing a box jump.  This shows some of the predisposing problems that might lead to an ACL injury.  The 2 most notable are the upright landing position and the valgus alignment.

In the following picture, you will see the same athlete after going through the 6 week training program.  Notice the depth on landing and the more neutral position of the knees.

After completion of the program, it is suggested that the athlete perform certain aspects of the program periodically to reinforce these new good landing habits.  This can be done as part of a warm up routine.