How can sitting too long cause your knee to hurt (and other problems)?

The Most Common Finding I See With New Patients: Pelvic Torque

The most common thing I see with a new patient is unleveling of the pelvis variously called pelvic torque or pelvic drop. Most often the right side is lower than the left. A simple motion test (the legs are lifted like a marching step) generally shows the high side, usually the left, not moving correctly (not rotating backward and down).  When we lay this person down we will see the right leg shorter than the left. This long leg/short leg phenomenon causes changes in the muscular system and the bony structure that can result in other problems.

Most serious problems happen on the side of the high pelvis. There is compression at the base of spine, the lumbosacral junction. It often manifests as pain on that side anywhere from the buttock area (often the piriformis muscle) all the way to the lower leg and calf. The pain often stops around the knee but the presentation is variable. The solution is to level the pelvis which is easily accomplished but sometimes hard to maintain. That’s why repetition is important. Reprogramming the posture is the route to long term change. Neuroplasticity is the new buzzword which describes how the nervous system “learns” or “re-learns” more defensible, healthful musculoskeletal positioning, We will discuss neuroplasticity more in an upcoming blog.

Along with adjusting the pelvis to eliminate the short leg and restore pelvic balance it is almost always necessary to adjust the lumbosacral articulation to take stress off the compressed spinal joint. We call this condition ‘facet syndrome’ because it results from compression of the spinal facets (the true spinal joint, each vertebrae has four, in each of the four corners). Caught early in the process healing can occur quickly if a level pelvis is maintained. If this conditions lingers it results in degenerative changes including disc compression or even disc herniation.

Now what about that knee pain related to sitting too long? Turns out that sitting is one of the major causes of the unlevel/torqued pelvis.   Imbalanced weight bearing from the pelvis results in imbalanced weight bearing on the knee joint. This unequal weight bearing results in the loss of the normal ‘screw-home’ mechanism between the thigh bone (femur) and the lower leg bone (tibia). This mechanism serves as a critical function of the knee and only occurs at the end of knee extension. There is an observable rotation of the knee and this rotation is important for healthy movement of the knee. The loss of rotation causes abnormal wear and tear and eventually pain and degenerative changes.  Abnormal weight bearing due to the unlevel/torqued pelvis is the cause of the problem.

So not only do we need to adjust the pelvis to level it and usually the lumbosacral/lumbar joints to eliminate compression but sometimes the knee joint is adjusted to restore  the ‘screw home’ mechanism.

Unfortunately the pelvis, lumbar spine and knee joint are not the only fallout from the damnable pelvic torque.  There is the issue of shortening of the paraspinal muscles on the high side causing shoulder problems. Although not seen in a majority of cases it happens often enough that we will go into potential shoulder issues in a future blog.

After all that technical talk there are two important takeaways: Pelvic torque/imbalance/unleveling or whatever you call it, is correctable and important to eliminate along with the other musculoskeletal problems that frequently accompany the syndrome. Second, fixing the ergonomics of your situation whether it’s from work, hobbies or just lounging around is important to avoid painfully unpleasant musculoskeletal pathologies. So talking about sitting and the general area of ergonomics is an important topic for another blog.