Knee pain is one of the most common problems encountered by runners. Initially, most people are concerned they have injured themselves, tearing the infamous ACL (anterior cruciate ligament) or MCL (medial collateral ligament). This is quite reasonable, however knee pain (particularly in runners) is frequently the result of long established imbalances between certain muscle groups.
With these imbalances altering the mechanics of the lower limb, abnormal stresses are placed on the tissues. If the body is then asked to work harder than it is used to, inflammation and pain can result. Often, this pain can be surprisingly severe, leading one to wonder whether something serious is going on. Nonetheless, treatment to restore normal function to the limb, followed by therapeutic exercise, can bring quick resolution.
Knee pain in the absence of obvious injury is a foot or hip problem until proven otherwise. Non-surgical knee pain revolves around three structures. One is a portion of the quadriceps (big muscles on the front of the thigh) called the vastus medialis, or VMO. The second structure is a broad sheet of connective tissue running from the hip to the knee, called the iliotibial band, or ITB. As a result of sitting a lot, the ITB tends to shorten. The third structure is the kneecap, or patella. The shortening of the ITB has the effect of pulling the patella to the outside, a movement resisted by the VMO.
However, muscular activity is governed by something known as reciprocal inhibition, which means that when a muscle contracts, the muscle opposing it relaxes. What this means is that tightening the ITB deactivates the VMO, to some degree. Together, this imbalance pulls the kneecap (aka the patella) to the outside, distorting how the knee moves. Ultimately, the patella is a passive structure; the groove it rides in is made up of the shin bone (the tibia) and the thigh bone (the femur). Misalignment on either end will pull the patella out of its alignment.
If twisted tracks derail a train, the train isn’t the problem. This also typically ripples up and down the leg to the pelvis and the foot. From here, it’s just a matter of what starts hurting first: the patella, or the ITB. Diagnoses exist as insurance industry labels; if the doctor submits a diagnosis (label), it justifies the company paying for the treatment. While they have different labels, both problems exhibit abnormal movement of the kneecap, known as the patella. On a certain level, the only real difference is where pain starts: the ITB, or around the patella.
Changes in these three structures can have a couple of effects. First, in a repetitive activity like running, the now-tight ITB can become inflamed by friction. This is usually labeled an iliotibial band syndrome. Second, the kneecap may begin to track towards the outside of the knee, irritating the underlying cartilage. This is usually labeled a patellofemoral pain syndrome (PFPS). In many cases, I have seen this manifest as a severe pain directly behind the knee that comes about a mile into a run. Third, both problems can be present (and usually are).
So if you have these problems, what can you do about it? You may think you can stretch your way out of it; unfortunately, the muscle imbalances usually throw off the mechanics of the joints in the low back, pelvis, and leg. Furthermore, it is very difficult to effectively target the tight muscles with stretching, because as they shorten the fibers become glued together, in what are known as fascial adhesions.
The best treatment for this is known as Active Release Technique (ART). ART is a soft tissue diagnosis and treatment system which breaks up the adhesions by having the patient actively lengthen the muscle, while the practitioner uses their hands to trap the muscle in a shortened position. The process is often somewhat uncomfortable, but the process also reinforces normal movement patterns, neurologically re-educating the patient. Generally, chiropractic adjustments are necessary as well, applied to the pelvis, leg, or low back, allowing the joints to move freely within their normal range of motion. Finally, the body needs to be reminded to move normally again with therapeutic exercise.