When it comes to sports injuries the most common questions that come up are how to avoid an injury and what to do if an injury is sustained. The good news is that there is quite a lot we can do to prevent injuries. In the next few issues of Great Health GuideTM, we will be reviewing a few of the more common types of injuries and talking about how to prevent and manage them.
In this article we will focus on knee pain – patellofemoral joint syndrome.
Please note these tips are only general and are not a substitute for seeing a trained health professional. If in doubt about the severity of an injury you should see your doctor or physiotherapist for an assessment.
What is patellofemoral joint syndrome?
Patellofemoral pain syndrome is a common complaint in all age groups and levels of physical activity. It is the term used to describe pain felt behind the patella (kneecap). Specifically, where it articulates (joins) with the femur (thigh bone). This joint is the patellofemoral joint.
Actions such as walking up stairs, kneeling, running or squatting can be provocative. This generally occurs as a result of poor kneecap alignment, causing excessive pressure in the joint.
Causes of knee pain
The main causes of patellofemoral pain syndrome are muscle imbalance and poor biomechanical control. Let’s review each of these factors.
1. Muscle imbalance
Your quadriceps (front of the thigh) muscles attach to the patella and are responsible for straightening the knee. The quadriceps are a group of muscles, two of which are the vastus lateralis (VL) and the vastus medialis oblique (VMO). The VL pulls the patella up and outwards, while your VMO pulls it up and inwards. If there is a weakness in the VMO, there will be less force pulling your patella inwards, meaning that it will be pulled further outwards than normal and not glide smoothly as you bend and straighten your knee during exercise (such as running). This can occur as a result of previous knee injury, post-surgery, swelling or simply lack of strength built up in the area relative to the opposing muscles. Tightness in your lateral thigh muscles may also pull your kneecap outwards slightly.
2. Poor biomechanical control
Poor foot posture, such as flat feet, can contribute to patellofemoral joint syndrome. When movements (e.g. jogging) are consistently repeated, your knee will be repeatedly traumatised which over time results in this pain experience.
Weak hip control muscles can also contribute. These can result in abnormal twisting of the knee, causing the patella to move slightly out of position when walking or running.
So what can we do to prevent and treat knee pain? The first step is to make sure that the diagnosis is correct. Since the cause of patellofemoral joint pain is mostly routine tests such as ultrasound, X-Rays, CT scans etc., they will often not show anything as there is no fracture, muscle strain etc. Your physiotherapist, however, will be able to perform a few functional tests in order to confirm/rule out patellofemoral joint pain and prescribe the treatment. However, if your symptoms don’t improve after a few sessions, your physiotherapist will refer you for the routine tests in order to see if there is anything else which might be causing your symptoms.
It is estimated that 90% of sufferers are pain-free within 6 weeks of commencing a physiotherapy rehabilitation program. The following steps will help.
Initially rest from provocative activities is recommended, with the use of ice advised for any obvious swelling following a strenuous bout of activity which has aggravated the pain.
Range of motion and muscle length.
Your physiotherapist will assess whether you have a limited range of motion in your knee, hip or ankle joints and address this if any of them appear to be contributing to the problem. This can be done through passive or active stretching, soft tissue massage, use of foam rollers and other methods.
Strength and control.
It is important to address the cause(s) of the issue. If it is suspected that weakness of the VMO (as discussed above) is to blame, then a graded strengthening program will be implemented. This generally begins with fairly simple exercises in non or partial-weight bearing positions, progressing into more strenuous exercises as strength is built up.
A hip strengthening program may also be implemented, which largely involves strengthening of the gluteal muscles responsible for hip control.
Correcting poor technique.
You may have developed poor habits as result of experiencing knee pain. This may include a modified walking pattern, squatting technique or jumping method. This can also be addressed by retraining these activities.
Finally, the elements which are important to an individual’s usual physical activity can be addressed. An elite athlete will need to make sure that their speed, power, proprioception and agility are at an optimal level before returning to competition. Even those who do not compete at an elite level will likely have certain hobbies or exercise routines they may need help returning to safely.
Other treatment modalities.
The use of ultrasound, heat packs, electrical stimulation, including SCENAR therapy, soft tissue massage and others may be necessary to speed up or aid in the recovery process. Your physiotherapist can advise what is most appropriate for you.