Google+ Badge

Wednesday, February 5, 2014

My Kneecap Keeps "Popping" Out

Dislocated patella
It's very common when presented with a history of one's kneecaps "popping out" for a doctor to refer the patient for physical therapy with a prescription of "Knee Strengthening/Quadriceps Exercises" and "ITB Stretching".

The medical term for this situation is "patellofemoral instability", where the patella (kneecap) has a tendency to sublux (or even dislocate) as it glides over the femur (thigh bone). I like to explain this to patients as if a train (your kneecap) is coming off of its tracks due to poor alignment.

Your patella derailing off your femur

Why does this happen?

Despite what conventional wisdom would tell you that it's weak muscles around the knee that cause the instability, it's actually a bit more involved. The usual suspects in conventional thinking to "blame" are a "weak" vastus medialis obliquus (VMO) and a "tight" iliotibial band (ITB).


 

In reality, the cause is more functional in that you can think of the knee joint as the middle man in-between the hip/pelvis above and the foot/ankle below. And like all middle men, they react to what's going on with the opposite ends of the chain.

When the patella subluxes, or "goes out of place", it's usually lateral of the femur. In not so severe cases, because the soft tissue structures involved are still contained, the patella usually glides back into place with a straightening and bending motion of the knee (i.e. it falls back into its track)

When the pelvis is in a less than ideal position, it will affect the function of the hip joint which will affect the function of the knee joint below. Likewise with the positioning of the foot and ankle can affect the knee joint above.

You can think of the pelvis/hips as the steering wheel, the knee and the foot/ankle as the wheels. What happens when your steering wheel is out of alignment? More wear & tear of the wheels.

Here's a typical clinical presentation:

The pelvis on the same side of the involved knee is either rotated too far forward or backward, with either way, there's a compensation at the knee where the femur (thigh bone) either wants to roll inward excessively or can't roll inward enough. Either way, the vastus lateralis (VL) quadricep muscle can be overly worked to maintain  a stable amount of internal rotation of the femur. Because the ITB covers the VL, it commonly is mistaken as the "culprit". And because the VMO wants to do the opposing motion of external rotation of the femur, it is often "out-classed" by the VL.

Can you see now why doctors prescribe "quadriceps strengthening" and "ITB stretching" for patellofemoral situations?

Everything's connected
The moral of the story is that everything is connected and with patellofemoral instability situations, I find what works is addressing what's going on above (more than below) the knee joint. Obviously every case is unique and I could go on about many other possible relationships, but what it comes down to is what is the primary driver, or the "Mother", behind the clinical presentation and the only way to find out is through a thorough clinical evaluation along with a barrage of assessment/reassessments of function.

So the next time you're in the Greenwich Village and/or Union Square neighborhood, consider coming by Michael Jocson Physiotherapy for a check up. You'll be glad you did.....
:)

9 comments:

Angela Killpack said...

Is it common for people's kneecaps to move like that? I don't think I've focused on strengthening any muscles around my knee, but my kneecap has never done that. Is it genetic? http://www.westmountphysio.com

Hospital Khoj said...

Ahmedabad is counted for having some of the best hospitals of country. Many hospitals in ahmedabad have established themselves in last few years as premier providers of world class quality professional care in medical facility environment.

RK Gupta said...

Jaipur has many leading hospitals of our country. Many Hospitals in Jaipur have recently developed with world class doctors, professional equipments including recent technology and much more.

Олег Кієнко said...

wow!Thank this meaningful http://topassignmentwriters.com/
and helpful post !And I like help people make research paper

Bogdan Yanov said...

Great Post !! Very interesting topic will bookmark your site to check if you write more about in the future my site

www.buyessayonline.net said...

Even an essay writer proved my words.

Lifeatbest said...

Here know about the best hospitals in India which provide knee /hip replacement surgeries with advanced medical facilities by highly specialised doctors.

Inez Shutts said...
This comment has been removed by the author.
Anonymous said...

Physical exercise is the best medicine for kneecaps... atleast you can be free from the pain.. Here are some of the Best Knee Pain Exercise

Request you to practice these daily.. you can surely feel the Relief in pain of the knee.. also the exercise should be depend on whether your problem is acute knee pain or chronic knee pain