Ask Stephanie: How Does the Knee work and what can cause knee pain?

Knee pain is a common problem for anyone from runners to cyclists to yoga enthusiasts. Understanding how the knee works can be critical to preventing long term knee pain and keeping your knee joint healthy!

How Does Your Knee Work?

There are several structures in your knee joint that make movement easier. One is the knee cap or the patella. The patella sits in the groove at the end of your thigh bone or femur. This area at the end of your femur is called your trochlea. When you bend and straighten your knee, the patella moves back and forth inside the trochlear groove.

Articular cartilage covers the surfaces of these bones to help them slide more easily over one another. Synovial material and fat pads also lines the joints help the sliding movement and provide cushion for the bones.

What Causes Knee Pain?

Patellofemoral pain is a condition that can be caused by vigorous activity that puts repeated stress on the knee particularly the structures listed above. It can have several causes but malalignment is a big contributor.

When the patella tracks abnormally over the trochlear groove, the patella can get pushed to one side more than it anatomically will tolerate. It can cause increased pressure on the patella and trochlear surfaces and irritate the tissue between the two bones.

Factors that contribute to poor tracking of the knee cap include:

1. 1. Problems with alignment of the legs between the hip and ankle. When the alignment of the upper and lower legs is less than optimal, the patella sits just out of midline of the trochlear groove. This can lead to wearing of the structures that were discussed above.
2. 2. Muscular imbalance including the quadriceps muscle. The quadriceps muscle and the patellar tendon help to keep the kneecap in the trochlear groove. Weak or imbalanced quads can cause poor tracking of the knee cap in the groove, also contributing to pain and dysfunction. Weak muscles in your hip and core can also do the same. A thorough physical exam by a qualified physical therapist can help you to determine what muscles would benefit from strengthening to help manage the dysfunction.
3. 3. Connective tissue tightness in the leg. Structures like the iliotibial band on the outside of the thigh or tight muscles in the hips can contribute to imbalance because they pull the structures of the knee and leg out of alignment which can cause muscles to work either less than or more than normal.

How can Physical Therapy Help?

Tissue mobility and balanced strength are important to optimizing alignment in the knee. A physical therapist can help you to determine what is weak or tight so that you can improve the efficiency of your knee movement and keep moving!

Want more information? You can schedule a complimentary phone consultation to discuss your symptoms here.