Patellofemoral pain syndrome (PFPS) is pain at the patellofemoral joint. This joint is the contact point between the knee cap (patella) and the upper leg bone (femur). The knee cap (patella) is imbedded into the quadricep muscle, which will be important to remember when we talk about the cause of pain.Patellofemoral Pain Syndrome (PFPS) results from the patella (kneecap) rubbing on the femur bone underneath. It may also be known as Runner’s knee, Chondromalacia patellae, anterior knee pain, and Patellofemoral joint syndrome.
Looking at the feet, pronation and/or flat feet rotate the lower (tibia/fibula) and upper (femur) leg inwards. When they rotate in, the knee cap (patella) also rotates in, causing the joint to be in the improper position. Contributing to the misalignment are the quadricep muscles (on the front of the thigh). The quadriceps contain a group of four muscles. Three of these muscles are pulling the knee cap (patella) slightly outside, where only one is opposing these muscles and pulling in. When the foot rolls in (pronation/flat feet), rotating the lower and upper legs in, the three muscles on the outside are at an advantage and pulling even harder on the knee cap.
Muscle imbalances can originate from foot pronation/flat feet, or can be from other causes. If the inner quadricep muscle is too weak, the outer quadricep muscles will pull at the knee cap (patella) causing improper tracking at the joint.
This can be caused and/or exaggerated from bad form. Squatting with the knees pointing inwards will strengthen the outside muscles and almost ignore the inside muscle. This improper squatting can begin from foot pronation, or from another cause.
Poor Leg Posture, this is much like having bad wheel alignment on a car causing uneven wear on the tyres. The most common presentation is a “knock kneed” posture. This is often due to flat feet, weak gluteal muscles and/or poor muscle control.
Symptoms include an aching pain in the knee joint, particularly at the front of the knee and under the patella.
Typical assessment findings:
Ineffective Physical Agents:
Systematic reviews and RCTs have demonstrated a lack of evidence supporting the use of physical agents such as:
Strengthening Exercises:
Strengthening exercises have shown positive results, particularly:
Stretching:
Targeted stretching is crucial. Key areas to address include:
Specific Stretches:
Taping:
Kinesio taping, particularly the McConnel technique, is a popular treatment. The aim is to correct lateral patellar maltracking and patellar tilt. This technique can be used during training and competition.
Patellar Braces:
Patellar braces apply an external, medially directed force to counteract lateral patellar maltracking. Biomechanical studies suggest they can alter patellar tracking.
Soft Tissue Manipulation:
Soft tissue manipulation corrects fascial thickening and shortening.
Multimodal Approach:
A multimodal approach is highly recommended for reducing pain in athletes with PFPS in the short and medium term. This involves a combined program of:
Return to Sports Criteria:
An athlete can return to sport when the following criteria are met:
Plyometric Exercises:
Plyometric exercises increase muscle power and bridge the gap between traditional rehabilitation and sport-specific activities. Start at low intensity and gradually progress to high intensity, performing the exercises three times per week. Training programs generally range from 6 to 15 weeks.