Are you at a higher risk for ACL injury

By Dr. Ben HOKENSON

 

Anterior Cruciate Ligament tears are common in sports, and may not fully recover. Prevention can possible with awareness of faulty movement, and retraining patterns of weakness.

  • ACL tears are one of the most common knee injuries
  • Most ACL tears are the result of landing from a jump or planting, cutting or pivoting in sports; most commonly without contact.
  • ACL reconstruction is generally necessary if you want to regain knee stability to return to sport since the ACL is crucial for stabilizing the knee when turning or planting.  
  • The anterior cruciate ligament is one of the four main ligaments of the knee, and the ACL provides 85% of the restraining force to anterior tibial displacement at 30 degrees and 90 degrees of knee flexion
ACL.jpg

Do you have any of these 3 Risk factors?

1.  Are you Female? Females are 4-5x more likely to tear and ACL than men.

Reason: Multi-causal, turns out its not a simple answer; anatomical and geometric differences of the knee and hip, as well as hormonal and genetic differences create difference stiffness and strength in the connective tissues.

2.  High BMI (body mass index)                                                                              

Reason: Although BMI is currently thought to be a poor barometer for healthy weight and fitness, in this case, higher body mass can be harder for ligaments to support during intense sporting activities.

3.  Poor neuromuscular control/motor control (coordination of movement)       

Reason: We rely on muscle control to support our joints throughout most of the range of movement.  When muscles don't fire properly, poor movement patterns result and more stress is endured by your joints and ligaments.  We can evaluate this in the office and gym with a couple simple movement tests.

A few signs of poor motor control in the lower extremity

Excessive pronation of the feet; inwardly rotated or pointed knees during standing, squating and/or jumping; poor stability and balance standing on one leg; poor posture

Would you like to test your motor control? 

The Box jump off test is a simple and safe test to perform yet can be complex to fully analyze.  Movement based health professionals may use the "Landing error scoring system"/LESS which requires video analysis of the action to fully analyze. This test may be simplified for general impressions of ones motor control abilities. 

If you would like to read an in depth look at the Landing error scoring system click on the link below.

http://natajournals.org/doi/pdf/10.4085/1062-6050-50.1.10?code=nata-site

Key points: ( not a fully inclusive list)

  • Can the person "stick" the landing?
  • What is the foot position at landing? Heel to toe? Midfoot?
  • Is the entire movement performed under good control?
  • Do the knees track straight without excessive inward deviation?
  • Is there excessive foot rotation, either internal or external?
  • Is there excessive trunk flexion?
  • Is there excessive joint movement overall?
  • Does one foot land before the other?

 

The Y balance test, is another great test to quantify your stability and motor control, and is used as a marker for improvement in performance and injury risk.   This tests compares strength and stability from one side to the other.  

 

How's your motor control?  

 

References:

Padua, D. A., Marshall, S. W., Boling, M. C., Thigpen, C. A., Garrett, W. E.,Jr, & Beutler, A. I. (2009). The landing error scoring system (LESS) is a valid and reliable clinical assessment tool of jump-landing biomechanics: The JUMP-ACL study. The American Journal of Sports Medicine, 37(10), 1996-2002. doi:10.1177/0363546509343200 [doi]