Why is the front of my knee hurting?

Knee pain is the complaint I see most commonly in the clinic.  Anterior knee pain, patellofemoral pain syndrome, chondromalacia, IT band syndrome.  There are lots of different names for knee pain with even more diagnosis categories.

I want to talk a little bit about patellofemoral pain. Long story short this pain generally comes from overuse at the front of the knee where your patella glides over the groove in the femur. Side note, overuse is a stupid term really. Running doesn't hurt your knees, the way YOU run hurts your knees.  Let me explain. 

The patellofemoral groove seen above is designed to match up with the under side of the patella itself. This allows for a large surface area for force to be distributed. During athletic movements its quite common to see multiples of your body weight in force to be placed on the knee. The larger the contact surface area between femur and patella the better off you are. We see folks get into trouble when that contact surface area is reduced. The same forces are placed on a small area, repeatedly. Think running, cycling, gym work. Rep after rep. This continual stress causes tissue to become irritable. Simply stated, your knee is going to hurt.

So how does this surface area become reduced in the first place? Knee valgus is the most common culprit I see clinically. What the hell is knee valgus?

This is some serious knee valgus. Ouch!

This is some serious knee valgus. Ouch!

Robert Griffen III at the NFL combine a few years ago showing off some real deal knee valgus. To be clear, knee valgus is lame. The internal rotation at your femur is a critical factor when we talk about anterior knee pain. As the femur internally rotates the groove of the femur, which is the contact surface area of the patella does as well. This is not ideal. When we change that position the patella is setup to glide toward the lateral groove of the femur. More simply stated, as the knee collapses inward the patella tends to ride on one side of that groove versus between the two of them. This reduces the surface area. Ouch. 

This image was taken from an article published by Chris Powers, PhD, PT, JOSPT 2003

This image was taken from an article published by Chris Powers, PhD, PT, JOSPT 2003

This image was taken from an article published by Chris Powers, PhD, PT, JOSPT 2003

This image was taken from an article published by Chris Powers, PhD, PT, JOSPT 2003

The issue here is simple, improve the contact patch or surface area of patella on femur and spread that same force out over a larger surface area to make your knee feel awesome again. Simple!? So the first question I get in the clinic when I explain this concept is, "am I pronating too much?" Probably not! There are certainly cases where excessive pronation is a factor but I do not find that commonly. Think critically about all the joints in the foot and ankle that must translate movement up the chain to create a medial collapse at the knee. It can be done but thats quite a feat. More realistically this movement is coming from the femur itself. Internal rotation at the femur has direct action on the knee joint. Your femur is in fact half of your knee! One to one relationship.

The fix here is to gain more control from your glutes, glute max specifically. The orientation of the fibers of this muscle make it an optimal performer when it comes to reducing internal rotation at the femur. Lay off those quads and focus on the glutes a litte bit more to gain access to better control at the femur and to get back out there, pain free!