Patellofemoral Joint Pain (PFJP)
The patellofemoral joint (PFJ) is a common source of anterior knee pain amongst the general population, and is even more prevalent amongst the running population.
The PFJ, is the joint between our patella (kneecap) and femur. The patella bone itself increases the mechanical advantage of our extensor muscles (quads) and is the principle site of insertion of our quad muscles. The PFJ is a joint that is subject to complex loading (both tensile and compressive) that is dependent on knee joint position. It is poor transmission of load and ‘tracking’ of the patella in its groove that is primarily responsible for PFJ pain and symptoms.
Symptoms associated with patellofemoral joint pain (PFJP) can include:
- Pain at the front of the knee (often gradual onset)
- Symptoms aggravated by activities such as: running / jumping / stairs / squatting / kneeling / prolonged sitting with knees bent
As with all injuries; there are a number of contributing factors that need to be considered with managing PFJP. Key contributing factors include:
Deficits in hip muscle function
Quads weakness / Delayed activation of VMO (Vastus Medialis Oblique)
Reduced trunk and pelvic control
Increased foot mobility
If we keep things consistent with previous running injuries in this series, we can break the contributing factors down into intrinsic and extrinsic factors:
Intrinsic factors: reduced quadriceps strength, delayed activation of VMO, reduced hip strength, reduced lumbo-pelvic control, reduced femoral control, foot posture, weight, knee / hip anatomy, running technique
Extrinsic factors: training load, training environment, footwear etc.
In most cases it is a combination of these factors that lead to developing patellofemoral pain when running.
All these contributing factors will have an effect on biomechanics and PFJ load transmission. For example: Reduced strength or lack of control of hip and trunk can have a huge impact on the load demands and tracking of the PFJ.
Once again…try not to get distracted by the symptoms, instead hunt the cause.
So…what can we do to manage, fix & prevent PFJP?
- Assess for contributing factors: we are all different, what may contribute to one person’s knee pain may not be a factor at all in the next.
- Activity modification: this doesn’t necessarily mean no running! But, essentially load needs to be modified as best it can to reduce symptoms and allow management to progress.
- Quad & gluteal strengthening: it needs to be functional and specific to the individual. The options are endless.
- Trunk strengthening & control: it’s important for biomechanics, it’s important for load transfer.
- Movement pattern re-training: this is not just a matter of strength; but control, activation and technique.
- Taping: taping is effective in reducing pain in the immediate term; but it is not a fix.
- Stretching: as needed, based on assessment findings.
Managing PFJP essentially involves improving the intrinsic factors that are identified to be contributing to PFJP and modifying running load as strength and control improve.
If you have any questions about knee pain you may be experiencing please don’t hesitate to call or email: (03) 5229 3911 or firstname.lastname@example.org.
Or follow the links for services that may help…
Barton, C.J., Lack, S., Hemmings, S., Tufail, S., Morrissey, D. The ‘Best Practice Guide to Conservative Management of Patellofemoral Pain’: incorporating level 1 evidence with expert clinical reasoning.