What is it?
Patellofemoral pain is pain from the tissues within or surrounding the joint between the knee cap and the femur (or thigh bone). It can be a complex and challenging condition to treat as there are a number of factors that can contribute to pain in this area. Structures that can cause pain in the knee are the lateral retinaculum, plica, bursa, fat pads and the synovial lining of the joint. All of these have a very good nerve supply and when something is up with them, they will cause pain. Interestingly the underside of the patella (or kneecap) itself actually has a very poor nerve supply and articular cartilage has no nerve supply. However chondramalacia involves changes to the cartilage on the underside of the patella and this can be painful, so nothing is set is stone and quite often the pain can be tricky to diagnose.
What are the symptoms of patellofemoral pain.
- Pain under or around the knee
- Its aggrevated by activities with high patellofemoral load. Examples are squatting, (especially deep squat), lunging, kneeling, going down stairs, running (especially downhill) and also by prolonged periods with the knee flexed or bent (this is because the knee cap has a large contact area with the femur in this position).
- There is usually little or no swelling and the knee does not lock.
- You will have full movement in the knee but sometimes it can feel a little stiff
So what can be done with patellofemoral pain?
Even if the exact structure of the knee cannot always be identified the patients pain can still be modified. My principles of treatment are:
- Settle down the symptoms and inflammation by reducing the load or force on the patella and the surrounding tissues
- Identify the cause of the problem and why it has happened in the first place.
- Rehab to deal with the cause -(normally involving strengthening the area).
- Gradually reload the area and return to the things you like doing, whether its sport or every day work or activities.
How to reduce the symptoms
If your pain is very severe then you should stop the aggravating activity, whether this is running or prolonged sitting.
Modify your running by changing speed, distance, frequency of running or stride length ( which can have a large effect).
Taping can be very effective and can immediately reduce pain by 50% or more giving you a chance to strengthen the surrounding muscles without aggravating the knee
Unless your load is reduced then it can be hard to change symptoms.
Identifying the cause:
Once the pain and symptoms have subsided then the investigation can begin into what is the cause.
The potential causes can be:
Training errors – if your a runner you may have increased your miles too rapidly or started hill training without building up appropriately
Muscle weakness – this normally involves glutes or quads strengthening
Muscle tightness. – sometimes lateral structures are pulling on the knee cap and pulling it out of alignment.
Running bio mechanics – flat feet, too large a stride length
Genetic and structural make up – Females can be more prone to patellofemoral pain due to their wider hip angle and also the shape of ones patella can lead to them been more at risk to getting knee pain
What is the treatment:
The treatment is not a ‘one recipe fits all’ solution. It needs to be tailored towards the individual and towards their muscle imbalances, biomechanics and lifestyle. Your physical therapist or health care professional needs to cater the rehab and treatment towards the findings they have made during the consultation and assessment.
Rehab will consist of open and closed chain exercises. The difference between them is that closed chain is where the feet stay on the ground and the body moves around them ( a squat) and open chain is where the feet and the limb move freely in apace (kicking a ball action).
Closed chain exercises work better in 0 – 45 degrees of knee flexion as they will not aggravate the knee in this position. Examples are step-ups and mini squats.
Open chain exercises work better at 90 – 50 degrees and 0 – 20 degrees of flexion. (0 degrees is with the leg straight, 130 degrees is with the knee fully bent). Examples of these exercises are: isotonics, different angle isometrics and straight leg raises. Performing Open an closed chain exercises in these specific ranges loads the quadriceps while having the least stress on the patella.
There are a number of exercises that can be done and I will be going through some of them in more detail in a later post so stay tuned for part 2. It is important that the right exercise is picked for the right stage of your injury and also that you perform it the correct amount of times so you do not aggravate your knee pain further. As ever if you are unsure then book an appointment with a physical therapist or health care professional who can educate you and send you on the right road to recovery.
As always, If in doubt – get it checked out