Assess & Address: Patellofemoral Pain Syndrome by Whitney Lowe

Pathology Assessment & Evaluation Treatment Massage Techniques

Assessment and evaluation
PFPS develops most commonly as an overuse problem. The client will report anterior knee pain that is associated with activities emphasizing flexion and extension of the knee. Especially common are problems occurring with running, jumping, climbing or descending stairs, as well as squatting. The pain is described as a non-specific aching in the anterior knee region that often improves with rest and gets aggravated during activity.

However, pain is not always relieved with rest, as this is somewhat dependent on the position of the knee during rest. A common pattern with PFPS is for the person to report an increase in pain if they sit for a long period with the knee in flexion, such as after traveling for a lengthy trip in a car or airplane, or sitting in a movie theater. Consequently, this pain is sometimes referred to as a “positive movie sign.” The pain will be felt immediately upon rising and will generally dissipate a few minutes after the person walks around. PFPS may affect one or both knees.

Sensations of grinding may also be reported when the knee is moved through flexion and extension. Pain is usually worse when flexion and extension movements are done against resistance or in a weight-bearing position.

For example, squatting would be more painful than sitting on the edge of the treatment table and extending the knee. Both motions move the knee through flexion and extension, but in the first case there is resistance to the extensor mechanism that would aggravate the PFPS pain. Unless the condition is in a very advanced stage, pain is not common with any passive movements because there is not enough stress on the involved tissues.

There are no outwardly visible signs of PFPS, though certain biomechanical or postural distortions can play a major role in this condition. Observing their presence is a helpful indicator. Especially important is the presence of genu valgum ("knock knees") or a large Q angle. These postural distortions will increase the tendency for lateral tracking of the patella because the angle of pull of the quadriceps muscle group is altered.

As a result of pain and dysfunction some muscles, such as the quadriceps, will atrophy rapidly. If there is a difference between the symptomatic and non-symptomatic sides, it may show up as a difference in muscle circumference, indicating muscle atrophy. While this does not specifically identify that PFPS is the cause, it does indicate that something is causing a degree of quadriceps atrophy and PFPS may play a role in it.

Another indicator that may be helpful in identifying the knee-extensor-system pathology of PFPS is the degree of medial and lateral glide of the patella. The patella should be able to freely move in these directions. However, it should not glide too much (see Figure 4). PFPS can be the result of either too much glide or too little. Somewhere around half its width appears to be the proper amount of side-to-side movement in the patella.

In some cases it will be difficult to reproduce the pain of PFPS with palpation and in other cases it can be easier. This is primarily because the tissue that is producing the pain can vary. For example, if the pain is primarily coming from irritation of the sub-chondral bone on the underside of the patella, it is not likely that light or moderate palpation anywhere around the knee will reproduce that discomfort. However, if the patella is pressed against the femoral condyles with greater pressure, the pain may be felt in this instance.

If, on the other hand, the pain is arising from more superficial tissues around the knee, such as the quadriceps retinaculum, it may be easy to reproduce the characteristic pain the client has been reporting by palpating this region. It is likely that pain will be exaggerated if these tissues are stretched, so the palpation should be performed with the knee in flexion.

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