Why do my Knees Hurt? Condition Overview: Patellofemoral Pain Syndrome
There are a lot of issues that can afflict the knees of runners but one of the most common is patellofemoral pain syndrome (PFPS). Speaking from personal experience, this issue can cause a lot of pain and limitations.
What is Patellofemoral Pain Syndrome?
PFPS is a term used to describe pain in the area of the patella, or knee cap. Most commonly in runners, it presents where the quadriceps insert into the upper portion of the knee cap. PFPS is a vague and generalized term used to describe anterior knee pain in the area of the patella. For this reason, symptoms, causes and treatment recommendations can and should vary.
What Causes Patellofemoral Pain Syndrome?
That’s the million dollar question. Though there is a fair amount of research, we still aren’t quite sure what causes this issue. So, let’s discuss some of the common assumptions.
- The patella glides in a groove on the femur. It’s stabilized in that groove by the quadriceps muscles and some ligaments. If the quadriceps muscle on the outer thigh (vastus lateralis) is stronger than the one on the inner thigh (vastus medialis), it can cause the patella to deviate towards the outside causing excessive friction leading to pain.
- The underside of patella is lined with cartilage. When this cartilage degenerates or is softened it can cause pain. This can be due to excessive use, injury to the knee or dysfunctional patellar tracking, as described above.
- Overuse of the quadriceps muscles can contribute to pain in this area. The knee is a leverage point for the quadriceps. If the hamstrings are too tight, the quadriceps have to work harder to overcome their tension. This can create an overuse injury, leading to PFPS.
- The Q-angle is the angle at which the hip and the knee are oriented. The thought process has been that people with wider hips (typically women) have an increased risk of knee complications. Research has suggested that this is no longer credible in determining risk factors for PFPS.
- Over-pronation of the feet can put excessive torsion on the knees, possibly leading to PFPS symptoms.
- A newer theory has to do with a small muscle called the articularis genu. This muscle sits on the front of the lower femur. It controls the positioning of the suprapatellar bursa. Bursae are small fluid filled sacs that are strategically placed in sites of potential friction to act as cushioning. If this muscle is dysfunctional, it may not allow the bursa to properly position itself to limit that friction.
Keep in mind that it’s possible that one or more of these is contributing to your symptoms.
Treatment Options for PFPS
Other than the Q-angle theory, correction of any of these issues has been shown to cause effective change in the symptoms of PFPS. Despite what I’ve seen on some popular running sites, there is no cookie cutter approach to treatment of this issue. The causes can be numerous and so must treatment.
In general, keeping the quadriceps and hamstrings stretched out is important. In some cases, strengthening of the VMO is helpful. Hip strengthening exercises are important to stabilize the pelvis which will decrease uneven loading on the knees.
My approach usually involves a combination of Graston Technique® and Active Release Technique ® (A.R.T.) targeting the quadriceps, hamstrings, articularis genu and hips. Again, this is all based on the patient’s individual presentation. I also like to include Rocktape® for added pain management and support.
Although it is small, the articularis genu needs to be assessed and addressed if it’s dysfunctional. Research suggests that this could be contributing to increased friction at the knee’s patellofemoral joint and in turn causing symptoms of PFPS. A.R.T. has a great protocol for treating this issue and in most cases, I have found it to be effective.
When I feel it’s necessary, I’ll recommend orthotics. Like I said earlier, research findings aren’t clear about the effectiveness of orthotics for this condition, but speaking from clinical experience, I’ve seen positive results.
It’s important to remember that research doesn’t give us all of the answers we need. While it’s helpful in guiding our approach, we need to remember that everyone is different and that some things just can’t be measured, which doesn’t mean they aren’t effective options.
Patellofemoral pain syndrome is a common condition among runners but don’t let that stop you from doing what you love. Be diligent in your injury prevention but be willing to seek professional help when you need it.
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- Woodley S. Articularis Genus: An Anatomic and MRI Study in Cadavers. The Journal of Bone & Joint Surgery 2012; 94 (1): 59-67. doi: 10.2106/JBJS.K.00157
- Kwon O, Yun M, Lee W. Correlation between Intrinsic Patellofemoral Pain Syndrome in Young Adults and Lower Extremity Biomechanics. Journal of Physical Therapy Science 2014; 26 (7): 961-964. doi: 10.1589/jpts.26.961.
- Freedman BR, Brindle TJ, Sheehan TF. Re-evaluating the Functional Implications of the Q-angle and its Relationship to In-Vivo Patellofemoral kinematics. Clinical Biomechanics 2014; 29 (10): 1139-45. doi: 10.1016/j.clinbiomech.2014.09.012.
- Rixe JA, Glick JE, Brady J, Olympia RP. A Review of the Management of Patellofemoral Pain Syndrome. The Physician and Sports Medicine 2013; 41 (3): 19-28. doi: 10.3810/psm.2013.09.2023.[/themify_box]