Monday, May 22, 2017

Knee Cap Pain- Patellofemoral Joint (PFJ) pain

By Will Dao

Knee cap pain is essentially pain at the front of the knee that can be caused from a variety of structures. However, it is sometimes used interchangeably with Patellofemoral joint (PFJ) pain. The patellofemoral joint is simply the joint between the back of the knee cap (patella) and the front of the thigh bone (femur). Common terms that have been used for PFJ pain include; knee cap pain, Lateral patella overload syndrome, lateral patella compression syndrome and Runner’s knee to name a few.

PFJ pain is a very common knee issue that affects 10-20% of the general population. It can affect both young, active individuals and relatively sedentary elderly people. Over 80% of patients presenting to Physiotherapy with non-traumatic knee pain can be attributed to having a patellofemoral joint component that is causing their knee pain.

The structures around the patellofemoral joint and anterior knee that can contribute to pain include but are not limited to:

Knee anatomy

  • Subchondral bone of the knee cap and thigh bone. That is, the bone under the articular cartilage of the joint surfaces.
  • The joint capsule or synovium of the knee
  • Bursae – the fluid filled sacks around the knee joint
  • Fat pad or the Hoffa’s pad
  • Tendons at the front of the knee.

Having PFJ pain does not exactly confirm which of the above structures are causing your pain but under a thorough assessment with one of our Physiotherapist’s we will be able to narrow this down and work out the cause of your pain. We also aim to identify whether pain is referred from the hip or lower back and in the rare instances from more sinister causes.

Fortunately, the majority of patients suffering from PSJ pain responds very well to Physiotherapy and are expected to see and/or feel an obvious change within 3-6 weeks. In the rare cases who fail to respond, Sports Physicians and/or Orthopaedic surgeons will be involved in your care.

What are the common complaints from people who suffer with PFJ pain?

  • Pain at the front of the knee – around or behind the knee cap
  • Pain walking up or down stairs
  • Pain when getting up after being sat for long periods.
  • Pain with kneeling
  • Pain with squats/lunges
  • Pain with running (particularly incline or decline) and/or jumping

What can cause PFJ pain?

  • A sudden change in training frequency or intensity with loading through the legs. This can include; an increase in walking/running, engaging more stairs/hills, increasing training volume, increase speed in running, more jumping and skipping, etc.
  • A change in footwear
  • Change in training terrain e.g. running on treadmill or grass to running on asphalt.
  • Direct impact onto the knee cap
  • Poor biomechanics with functional activities e.g. particularly flat feet can alter hip and knee position.
  • Imbalance of muscles around the hip or knees which can cause abnormal tracking or wear on the under surface of the knee cap.
  • Very stiff ankles which cause cause extra load higher up the chain with certain functional tasks e.g squatting or lunging.
  • Interesting facts – Patellofemoral joint loads (Compressive forces to PFJ)

Here are some interesting figures that may explain why you are getting anterior knee pain with certain activities:

  • Walking on flat surfaces incurs 0.5 times your body weight going through your knee
  • Stair climbing incurs 3 times your body weight
  • Down stairs incurs 5 times your body weight
  • Squats incur 7-8 times your body weight
  • Jogging incurs 7 times your body weight
  • Deep squatting incurs 20 times your body weight
  • How to fix PSFS?

Our primary goal is to work out what is actually causing your anterior knee pain or PFJ pain. It is also very important to work out what your ideal goal is to ensure our tailored management approach marries up with what you want to achieve functionally. We want to aid you in the process of getting fixed and will only stop you from doing what you want to do if absolutely necessary. We strive to keep you going.

There are a number of things we do at Fix Physio to help you get fixed and stay fixed from PFJ pain:

  • Activity or training modification is crucial to give your knee some relative rest from excessive knee loading type activities
  • Rigid Sports tape to provide some support over the patellofemoral joint
  • Kinesio Taping to support the patellofemoral joint or facilitate muscle activation around the knee
  • Promote low load mobility and movement of the patellofemoral joint
  • Identifying tight muscular structures that are affecting the mechanics of the knee e.g. quads/hamstrings/gluteals/ hip flexors
  • Provide manual therapy: Soft tissue releases, joint mobilisations, dry needling, foam rolling/stretching.
  • Retrain functional movement patterns e.g. squats and lunges.




  • Prescribe specific individualized exercises to help you achieve your functional goals.



Look out for our second blog on anterior knee pain which goes through a step by step progression on exercises to help manage your PFJ pain.

Call (02) 9231 0420 or book online at to have one of our experienced Physio’s assess your knee cap pain.

Get Fixed…Stay Fixed