Patellafemoral pain syndrome: “Runner’s Knee”
If you have ever felt pain of the anterior aspect of the knee such as behind or around the knee cap (patella) that can make simple activities exhausting or not worth the effort and pain that occurs during/after. Let’s dive into what it is, who is most effected, and how we can manage it.
Patellafemoral Pain Syndrome (PFP)
Defined as a common musculoskeletal condition that is characterized by an unknown cause of “poorly defined” pain localized to the anterior retropatellar and/or peripatellar region of the knee.
Also known as; pain front of knee behind or around the knee cap.
These symptoms can be slow to develop or can arrive suddenly/acutely with activities that load the lower leg; such as, squatting, prolonged sitting, going up/down stairs, jumping, running, etc.
This condition is defined as “self-limiting” by the literature. As someone who suffered with this syndrome for 12 years and ultimately pursued a degree in physical therapy I believe we deserve better. These symptoms can severely impact daily activities in addition to work or sport-related activities. Thus, impacting quality of life. Recent research states that 40% of people still suffer from symptoms one year after typical treatments and that 40% of adolesents carry this pain into early adulthood. Often with chronic pain and with children, personal experience talking here, self-reporting diminishes over time so these statistics could be way lower than actuality.
Who is affected by pfp?
PFP affects up to 29% of active adolescents and 23% of both active and sedentary adults in the general population. Females are affected twice as often as males.
What causes PFP?
Due to the nature of this syndrome there has not been anything specific identified as known causes of producing this knee pain. A recent study (Ramskov, et al., 2018) looked at common injuries in runners and progressing intensity or volume to see if this increased risk for injury. For PFP they did not find any associated increased risk with increasing running volume or intensity. A systemic meta analysis (Neal, Bartholomew, Barton, Morrissey, and Lack., 2022) investigated 6 treatments that had positive effects for people with PFP 3 months after treatment. This is looking at short-term benefit of the treatment provided, so this is something to be aware of as it cannot be generalized for long-term benefits. In the conclusion of this analysis they also state that no intervention showed adequate testing beyond the 3 month time frame.
Findings showed the knee-targeted exercise therapy for pain and function combined with interventions for pain and function had primary efficacy. Meaning these had the strongest results at 3 months post treatment.
Foot orthoses were also mentioned as having short-term primary efficacy for global rating of change. Something that our research is greatly lacking in is solid investigation into foot intrinsic strengthening and it’s impact on knee pain. In my professional and personal experiences, I found that improving strength and awareness of the foot has a massive impact on dispersed knee pain. Largely due to the fact our feet are often supported by shoes and orthoses, which allows the muscles to essentially become “lazy”.
Why does PFP keep coming back?
About a year ago, a blog was published by Deng, et al. on JOSPT looking at this specific topic. They found 3 very specific prognostic factors:
Duration of symptoms: the longer PFP symptoms are experienced the less likely exercise will reduce pain. Early intervention is key for this condition.
Older age: >40 years old are less likely to have positive outcome after knee-targeted exercise.
Greater body mass: greater body mass has shown to experience less positive outcomes from hip-and-knee-targeted exercise.
Exercises to target are specific to increasing strength in hip abduction and external rotation as well as knee extensor strength. There has not been a lot of research/trails on this mechanism yet, but is showing a good correlation to pain reduction and improving function.
What isn’t talked about in the rehab literature on pfp?
The mental aspect of PFP. Due to the dispersed and vague symptoms can lead to not being taken seriously when reporting pain. There is also the impact the mind has on our physical body that is often not addressed in traditional rehab approaches. At The Persistence Project we ensure to check in on new or re-occurring stressors in life that could correlate to onset of symptoms. We have several trusted mental health therapists that we refer to in cases that need referrals.
In Conclusion
To keep this blog post short and easy to digest we will leave it here and publish a part two in the future.
Patellafemoral Pain Syndrome is a complex and multi-faceted condition that affects a large portion of our population; adults and children. Traditional approach for physical therapy when utilized early onset has benefits with more potential for long-term relief; while the average shows symptoms return within 3 months after physical therapy. Research has not been done on looking at the foot mechanics and impact on training the foot intrinsics has on PFP.
