Unearthing the cause of anterior knee pain and ridding our patients and clients of it is one of the never ending searches for the “Holy Grail” we participate in throughout training and rehab circles.  I honestly believe we will never find one right answer or simple solution.  However, I do think we continue to gain a better understanding of just how linked and complex the body really is when it comes to the manifestation of knee pain and movement compensations.

We used to say rehab and train the knee if the knee hurts.  It was simply strengthen the VMO and stretch the hamstrings, calves and IT Band.  Slowly, we began looking to the hip as well as the foot and ankle as culprits in the onset of anterior knee pain.  The idea of the ankle and hip joint needing more mobility to give the knee its desired level of stability has risen up and seems to have good traction these days.

Likewise, therapists and trainers have known for some time that weak hip abductors play into increased femoral internal rotation and adduction thereby exposing the knee to harmful valgus loading. So, clam shells, band exercises and leg raises have been implemented to programs across the board.


Single Leg Resisted Hip External Rotation

As a former athlete who has tried his hand at running over the past 5 years, I have increasingly studied, practiced and analyzed the use and importance of single leg training and its impact on my performance and injuries.  As I dive deeper into this paradigm, I continue to believe and see the benefits of this training methodology for all of my athletes (not just runners).

As a therapist and strength coach, it is my job to assess movement, define asymmetries and correct faulty neuromuscular movement patterns.  To that end, I have developed my own assessments, taken the FMS course, and increasingly observed single leg strength, mobility, stability and power in the clients I serve. Invariably, I always find imbalances – some small and some large ones.

What are some of the most common issues I see?

Here is a list of the most prevalent things I see in many people I work with:

  • Poor hip strength/stability evidenced by an inability to keep the knee form caving in toward the midline of the body when loaded with bodyweight in a squatting or step-down maneuver
  • Tightness in the hip flexors and IT Bands
  • Tightness in the soleus and/or limited ankle mobility (dorsiflexion)
  • Trigger points throughout the lower legs (usually more so on the painful or injured side)
  • Limited hip internal rotation (often due to tightness in the glutes and piriformis)
  • Altered trunk strategies used to compensate for hip weakness

I say all this only to emphasize the need for single limb assessment and training to both correct imbalances and improve performance.  While single leg training is not the ONLY thing athletes need to do, it should absolutely be a part of any successful training plan in my mind.  To that end, more work needs to be done on assessing single leg tasks and how it gives us information about the body kinetically.

That is why I wanted to include an abstract for you taken from the April 2011 edition of the American Journal of Sports Medicine that examined the single leg squat task in relation to hip abductor muscle function.

Click here to read the abstract

While the study has some obvious limitations, it does identify the SL squat as a task as a reliable tool that may be used to identify hip dysfunction.  They rated subjects as good, fair or poor.  I have included a photo below to illustrate the way they assess it in the study (one difference is in the study participants crossed the arms)


To be rated as good, subjects has to fulfill all of the following:

Overall Performance

  • No loss of balance
  • Smooth movement
  • Squat to no less than 60 degrees
  • Squat is performed in 1-2 seconds

Trunk Posture

  • No trunk/thoracic lateral deviation or shift
  • No trunk/thoracic rotation
  • No trunk/thoracic lateral or forward flexion


  • No pelvic shunt or lateral deviation
  • No pelvic rotation
  • No pelvic tilt


  • No hip adduction
  • No hip (femoral) internal rotation


  • No apparent knee valgus (caving inward)
  • Center of knee remains over the foot

Note: the authors did not closely study the foot in this project.  Obviously, limited ankle dorsiflexion will encourage pronation and lead to a cascade of bad closed chain events for the hip and knee.  That is why I so strongly believe unlocking a tight ankle joint through mobilization, myofascial release, and exercise is so critical to ideal squatting, jumping, running and landing mechanics.  If you want to read more on this topic, check out my latest “Functionally Fit” column by clicking here.

I hope this post was insightful and Happy Easter to all my followers and readers!