What runner has not experienced some sort of knee pain? If you have not, you are onto something good. Unfortunately, every year about 2.5 million runners will be diagnosed with Patellofemoral pain syndrome (PFP) (5). PFP is also known in the streets as “runners knee” and unfortunately according to Powers 70%-90% of people suffering from PFP will have recurrent pain (3). So, what exactly is PFP? How does it develop? What are some symptoms of PFP? How can you prevent it? I am here to answer these questions.
What is Patellofemoral pain syndrome, and how does it develop?
Patellofemoral pain syndrome refers to pain in the knee and around the knee cap (patella) area. It tends to affect women more than men, and is very common in athletes especially runners. Up to now researchers have found this to be more of an overuse injury that develops from the patella tracking poorly over the knee joint.
It essentially develops from muscle imbalances of the lower quarter that cause faulty movement at the knee joint. The faulty movement causes excessive patellar friction /rubbing up against the femoral condyle and with prolonged stress ends up causing pain.
What are some specific contributing factors?
There has been a large interest in researching what exactly causing PFP, but for the most part most studies have found that the following factor tend to play a role in PFP (4):
· Poor tracking of the patella
· Excessive midfoot drop (pronation)- this will cause the lower leg (tibia) to rotate inwards causing the knee to dive in.
· Lack of ankle mobility, especially into dorsiflexion – alter foot position causing the foot to externally rotate, and promote midfoot drop
· Weakness of the hip stabilizers ( glutes ), which influence the position of the knee with the hip and foot, what we will most commonly see in the knee diving in too much.
· Excessive quadriceps activity- causing too much compressive forces of the patella-femoral joint or VERY weak quadriceps that lead to poor knee stability.
Look at my last 2 post about mechanics to get more detailed examples of mechanical faults in running. **
What does it feel like when you have PFP?
A lot runners describe an achiness around the knee cap or behind in knee cap. Some will also report some grinding or creaking.
Runners will report pain with:
· Going up/down stairs
· Increased activity /running
· Standing after prolonged sitting
How can you prevent it?
· Cross train and work on strengthening your glutes and quads, in a study conducted by Khayambashi et al, the researchers found that there was a decrease in knee pain after just 6 weeks of following a glute strengthening program in females with PFP. (1,2,3)
· Dedicate time to maintaining muscle flexibility especially those of your quads, hip flexors, and calves
· Be more aware of how you are moving! For example if you were to get up/down from a chair do your best to avoid the knees diving in. This pertains to all activities really : gym exercises (squatting, lunging, step ups), stairs, walking, sit to standing.
What to do if you think you may have it?
The root of the problem for each case may be slightly different.
Generally strength deficits and faulty movement tend to be the common impairments. But for those who think they may have PFP visit a physical therapist. Let someone take the time to access you and provide a catered plan of care especially if you have noticed that this has become a reoccurring problem. As therapists, our job is to be slightly nitpicky and assess movement, coordination, strength, and flexibility and assist you to returning to sport strong and ready!
Jessica Mena DPT, PT, CSCS
1. Fakuda, T., Rossetto F, Magalhaes E., Bryk F., Lucareli P., Carva N. Short Term Effects of Hip Abductors and Lateral Rotators Strengthening in Females with Patellofemoral Pain Syndrome: Randomized Controlled Clinical Trial. Journal of Orthopaedic and Sports Physical Therapy. 40(11) Nov 2010.
2. Khayambashi K., Mohammadkhani Z, Ghaznavi K., Lyle M., Powers, C. The Effects of Isolated Hip Abductor and External Rotator Muscle Strengthening on Pain, Health Status, and Hip strength in Females with Patellofemoral Pain: A Randomized Controlled Trial. Journal of Orthopaedic & Sports Physical Therapy, 2012 Volume:42 Issue:1 Pages:22–29 DOI:10.2519/jospt.2012.3704
3. Magahlaes E., Fakuda T., Sacramento S., Forgas A., Cohen M., Abdalia R. A Comparison of Hip Strength between Sedentary Females with and without Patellofemoral Pain Syndrome. Journal of Orthopaedic & Sports Physical Therapy, 2010 Volume:40 Issue:10 Pages:641–647 DOI:10.2519/jospt.2010.3120
4. Powers, C., Bolgla L A., Callaghan M.J., Collins A., Sheenan F.T. Patellofemoral Pain: Proximal, Distal, and Local Factors 2nd Internal Research Retreat. Journals of Orthopaedic and Sports Physical Therapy. 2012 August 31-September 2. Ghent, Belgium, doi:10.2519/jospt.2012.0301
5. Taunton JE, Ryan MB, Clement DB, McKenzie DC, Lloyd-Smith DR, Zumbo BD. A retrospective case-control analysis of 2002 running injuries. Br J Sports Med. 2002;36:95-101