In part 1 of our runner’s knee series, we discussed the specific anatomy involved, how and why we experience pain over/in the front of the knee, and most importantly, how running, and specifically downhill running, can hasten your onset of patellofemoral pain syndrome. ->Read Part 1 Here <-
Today, in part 2, we are going to move away from the knee and look at the friendly joints above and below. As we know, and you will soon find out, the hip and the ankle are in control of the knee and more times than not, pain at the knee is caused by faulty mechanics, immobility, or strength and stability deficiencies at either or both of these joints. Read on!
HIP FUNCTION IN RUNNING AND ITS RELATION TO KNEE PAIN
So that we have a starting point, we are going to travel from the hip down. Mainly because it is more commonly the culprit of running associated knee pain (my own clinical experience) but also because it is the bigger joint with more opportunity for complications.
To help explain how the hip acts on the knee, I commonly tell patients in the clinic that we have no ‘knee muscle’, but that everything controlling the knee, comes from the hip. While this is not exactly true, we have some very important muscles like the VMO and popliteus that act very strongly on the knee while not originating from the hip, but hopefully, you can read through that and see my point here. Control at the knee is primarily governed by the hip.
When we encounter a runner with patellofemoral pain, we will ‘treat’ the knee...but the majority of our work is spent on improving hip mobility, strength, and stability. What we find is that issues here can lead compensations, deficiencies, and imbalances that contribute to Runner’s Knee.
IT band tightness pulls on the patella causing it to track laterally, or to the outside.
Hip tightness can cause an anterior pelvic stance. This can inhibit and tighten the hamstrings causing an altered gait that is ‘quad heavy’. This tilt and tightening can lead to altered mechanics at the knee and also lead to patellofemoral pain.
Hip drop due to a weakness of the glute muscles can lead to what we are now calling the Miserable Malalignment Syndrome.
Let's talk about that last one for a minute as this is becoming more and more common in running associated knee pain. Miserable Malalignment Syndrome is the name now given to the cascading breakdown when the hip and ankle fail. Essentially, when our foot is planted, the glute medius muscle of the foot planted holds our pelvis level. When this weakens, the hip drops, causing the other side to respond. This response causes an inward rotation of the femur bone, an outward rotation of the tibia (shin bone) in an attempt to compensate, and lastly, a turning out of the foot resulting in a crashing in of the inside of the foot.
Guess which joint is in the middle taking all of that rotation torque?
I explain this in the video and picture below. Now, this condition got its name, not necessarily for runners, but for those who sit too much and exhibit the same pattern, but it fits here. If anything, this helps explain how important our hip mobility and strength is to the health of our knees. If you remember, as runners, we load the knee with 5-6 times our body weight with each and every step. Rotation in a joint NOT designed for rotation is destined to cause problems.
ANKLE FUNCTION IN RUNNING AND ITS RELATION TO KNEE PAIN
Now that we better understand the hip and its relation to knee pain, let's travel down the road a little to the ankle joint. Without getting into the kinematics of the ankle and the joints that make up this complex area of the body, let's just try to understand one thing...DORSIFLEXION.
Dorsiflexion is your ability to bring the top of your foot toward your shin. When we run, dorsiflexion allows us to strike the ground, react, and toe-off properly, pushing from our big and second toes. To help understand this, lets picture what poor dorsiflexion looks like. The next time you are walking around, look for someone who walks with their feet turned outward. What is usually happening here is that their hip tightness causes their posterior hip muscles (glutes, piriformis, etc.) to pull on the femur, resulting in an outward turned leg and foot. And...Unless they rode in on a horse, they are not walking with their kneecaps over their feet in this position which leads us to what we just discussed, the foot crashes inward, the kneecap points a different direction of the foot, and we now have pain. You can now imagine that there is no way this person is walking properly, meaning they are not actually toeing off correctly, but the inside of their foot, now...IMAGINE THIS PERSON RUNNING.
You may have realized that poor ankle dorsiflexion and the lack of hip mobility and stability can cause the same problem. The truth is, they tend to run together. While we will always treat any and all problems presented to us, it is my job to find the key that unlocks the whole system and more times than not, it is the hips!
TIME TO REVIEW WHAT WE LEARNED TODAY
Most of the muscular control of the knee comes from the hip. Lack of mobility and strength here can contribute to patellofemoral pain syndrome.
Lack of ankle dorsiflexion (the ability to bring the foot toward the shin) can cause outward rotation of the foot and undue rotational strain on the knee.
Issues at the hip and knee can lead to what we are now calling the Miserable Malalignment Syndrome. Essentially, when we run, our hips drop, causing an inward rotation of the femur, a counter-outward rotation of the shin bone, turning out of the foot and crashing in of the inner foot leaving the stress on the knee.
To properly address runner’s knee, we must address these deficiencies at the hip and ankle.
Once you have digested the information we discussed in these last two articles, keep your eyes peeled for part 3 next week as we will begin discussing what to do if you already have patellofemoral pain and when you should seek care so you can continue, or return to, training.
Dr. Reheisse is a Board Certified Chiropractic Sports Physician practicing in Cottonwood Heights Utah. Revive Sport & Spine provides evidence-supported chiropractic care and conservative sports injury management.