Knee pain is one common complaint among runners, with the majority of runners who seek help for knee pain being given a diagnosis of patellofemoral syndrome, or patellofemoral pain. For the purpose of this post, we will refer to this type of pain as patellofemoral pain syndrome (PFPS) . The symptoms of PFPS may include anterior, or lateral knee pain that occurs with activity. Sometimes, those with PFPS will report that the affected knee feels full, or swollen even if there is no swelling present.
The exact cause of PFPS is not clear; however, many clinicians believe that the pain may be due to increased forces at the patella (or kneecap), or poor tracking of the patella along the femur (thigh bone). Merriam-Webster defines a syndrome as, “a group of signs and symptoms that occur together and characterize a particular abnormality or condition.” The nature of syndromes is that they are not well understood. As a physical therapist, I have treated runners with this diagnosis. Often times, they had been to PT for this issue in the past, and had become frustrated as their PT seemed to change their reasoning as to why the patient had their pain at each visit. The reality is that this PFPS may be due to a number of factors.
Clinicians have historically pointed to altered hip mechanics as a cause of this pain. This alteration in mechanics is when the hip of the landing adducts and internally rotates. As a result, the hip opposite of the landing leg will drop, and the knee of the landing leg will dive in towards the midline of the body. One study looking at 21 women with PFPS and 20 women without PFPS found that the women diagnosed with PFPS had this type of altered biomechanics with landing and step down activity. Additionally, they found that the women with PFPS had decreased strength of their hip abductors. (5). Additionally, other studies as well as several systematic reviews have suggested that those with PFPS are more likely to have decreased hip strength than healthy controls.
So, does having decreased hip strength lead to PFPS?
While some studies suggest that having decreased hip strength may predispose one to PFPS, others do not (2). In my opinion, hip strength may predispose one to having PFPS, however there may be other reasons why people develop this condition.
There may be other biomechanical factors such as a decrease in hip extension, decrease in hamstring flexibility, or a decrease in ankle and foot mobility that somehow contribute to PFPS. One study suggests that having feet that excessively pronate may predispose one to PFPS. (1) However, I do not believe that it is the biomechanical factors alone that lead to this pain. The repetitive nature of the task that causes the pain as well as behavioral and psychological issues such as stress may also lead to PFPS. Much how there is now believed to be a behavioral component to low back pain, there may also be a behavioral component to PFPS. One study suggests that those with PFPS may have more psychological stress. (3)
So if you have PFPS, where do you go from here?
In one study, subjects with PFPS were given real time feedback on their gait as they ran on a treadmill. This was done over several training sessions where the amount of feedback decreased over time. They found that the subjects reported less pain, and had improved function and running form. The study followed these runners for a month after the training sessions, and found that the changes were lasting over that period of time. (4)
If you are having some pain around your kneecap, or you have been given a diagnosis of PFPS, seek out the advice of a healthcare professional, especially one that is knowledgable of biomechanics, and the biomechanics of running. Follow their advice. Do not be surprised if in addition to exercises to improve hip strength and flexibility, you also work on improving foot and ankle flexibility. Ask if they would be able to assess your running form while running on a treadmill or over ground, and give feedback. Recognize that it may not be just one thing that is causing your pain. You may realize that you are lacking in hip extension and ankle flexibility, while your strength is adequate.
Also know that stress may be a component to your pain. Stress is inevitable. We all experience it. It may be worthwhile to note some of the stressors in your life whether or not they are related to running. Are you training for a major race? Adding more miles? Doing more speedwork? Are you trying to set a personal record (PR)?
How is the stress in your non-running life? Is your job demanding much of your time? Do you have a family? Are you getting enough sleep? How is your diet?
It is important to take note of your stressors, because they may be impacting your pain. There may be some stressors such as work or family that you cannot change. This is fine (as I said, we all have stress), however it is important to note that this stress may affect you, you pain and your ability to heal. There may be other stressors such as diet, mileage or speed work that you do have control over.
While working to fix the biomechanics of your running, take the time to address other aspects of your life.
If you note that there are some factors such as diet or stress level that need attention, and are not sure where to turn for advice you may want to seek out other healthcare professionals. Nutritionists, psychologists, LMFT’s (licensed marriage and family therapists) may also be able to help.
Taking some time to view your running as a part of your life overall may help to give better insight into ways that you can get better.
- Barton CJ, Bonnano D, Levinger P, Menz HB. Foot and Ankle Characteristics in Patellofemoral Pain Syndrome: A Case Control and Reliability Study. J Orthop Sports Phys Ther. 2010;40(5):286- 296
- Herbst DO, Barber Foss KD, Fader L, Hewett T, Witvrouw E, Stanfield D, Myer G. Hip Strength Is Greater in Athletes Who Subsequently Develop Patellofemoral Pain. Am J Sports Med. 2015 November ; 43(11): 2747–2752.
- Jensen R, Hystad T, Baerheim A. Knee Function and Pain Related to Psychological Variables in Patients With Long-Term Patellofemoral Pain Syndrome. J Orthop Sports Phys Ther 2005;35:594-600.
- Noehren B, Scholz J, Davis I. The effect of real-time gait retraining on hip kinematics, pain and function in subjects with patellofemoral pain syndrome. British Journal of Sports Medicine
- Souza RB, Powers CM. Differences in hip kinematics, muscle strength, and muscle activation between subjects with and without patellofemoral pain. J Orthop Sports Phys Ther 2009; 39(1) 12-19.