Knee Pain with Running
My last blog
briefly covered the top 5 running injuries we see in the clinic. Knee pain is at the top of the list. Although there are several different diagnoses we find with runners, I would like to focus on Patellofemoral Pain Syndrome.
Patellofemoral Pain Syndrome (PFPS) is pain around the knee cap, usually due to a "tracking" problem as well as the patella (kneecap) compressing on the femur (thigh bone). The patella (train) travels along a groove in the femur (train track) when the knee is bending and straightening. Historically, it has been theorized that the Vastus Medialis Obliquus (VMO- a muscle attaching from inside of the thigh bone to the inside part of the kneecap) was to blame for patellar tracking abnormalities due to it's weakness and the Vastus Lateralis and IT Band (Quad muscle on the outside of the thigh and connective tissue running the length of the outside thigh respectively) dominance and tightness.
However, recent research (Powers et al. JOSPT, 2003 and Souza & Powers, JOSPT, 2010) has suggested that we may have had the train and track analogy all wrong. Due to advances in modern technology, we are able to view a dynamic MRI weight bearing. Meaning, we can see how the patella is moving in relation to the femur, weight bearing via an MRI. Or... I should say, we can see how the FEMUR moves in relation to the PATELLA. As mentioned above, it has been theorized that the train moves off the track due to VMO weakness and VL strength/ITB tightness. However, Powers et al. found through a dynamic weightbearing MRI that the femur actually rotates inwardly (internal rotation) under the patella. Meaning, the patella (train) stays it's course and the track moves away from the train.
This is significant since it changes how we approach PFPS. Combine femoral internal rotation with tight quadricep muscles, and now you are compressing the patella against a rotating femur which is a recipe for pain and grinding of the knee cap which can lead to chondromalacia of the patella.
Clinically, we do a video analysis
of running along with several biomechanical, range of motion/flexibility, and strength tests to determine the cause of PFPS. Through slow motion video, we can see the femur internally rotate in running as well as jumping, landing, squatting, and lunging. We will also determine which muscles are weak and which movements are restricted, thus causing the femoral internal rotation.
Shoes, feet, and ankles are also examined as accompanying factors of PFPS.
Example of Dynamic Functional Analysis
An example of stride angle
Typically, we see a quad dominant behavior in movement and running and lack of Gluteus Maximus and Gluteus Medius activation and recruitment. Tight hamstrings, quads, and hip rotators are often associated findings with PFPS. Less often, we see overpronation dysfunction of the feet and ankles, though gluteal weakness is often a culprit of overpronation.
Treatment consists of ART, Graston, Spidertech, rehab/strengthening exercises, and chiropractic if needed. Training and shoe advice are often provided to cover all contributors of PFPS.
If you have knee pain with running, feel free to email Dr. Jess at email@example.com or comment on this blog below. We'd love to hear from you.