Patellofemoral syndrome

Patellofemoral pain syndrome, also known as "runner's knee" or patellar syndrome, accounts for 25% to 40% of all consultations for knee pain in sports clinics.¹ This condition particularly affects active individuals and athletes who increase their training volume too quickly. As physiotherapists specializing in sports injuries, we regularly help patients achieve a full recovery.

Here's the good news: with the right treatment, the vast majority of people return to their normal activities. Let's explore together what causes this pain and how you can get rid of it.

What is Patellofemoral Pain Syndrome?

Patellofemoral pain syndrome is pain at the front of the knee caused by overuse or overload between the kneecap (patella) and the thigh bone (femur). This condition occurs when the joint experiences mechanical stress that exceeds its ability to adapt.

The patella, a triangular bone located at the front of the knee, plays an essential role in movement. It acts as a pulley for the quadriceps muscle, increasing its leverage by 30% to 50%, which allows the muscle to develop more force.²

What is the role of the kneecap in the knee?

The kneecap is a 'sesamoid' bone because it is located within the quadriceps tendon. This unique position allows it to facilitate the tendon's gliding motion during knee flexion and extension movements.

The patellofemoral joint is designed to withstand significant loads. When descending stairs, the forces exerted on this joint can reach up to 7 times the body's weight.³ This remarkable capacity explains why an imbalance between the applied load and the body's ability to adapt can lead to symptoms.

What causes Patellofemoral Pain Syndrome?

Patellofemoral pain syndrome is caused by mechanical overload on the kneecap-thigh bone joint. A too-rapid increase in training volume, a change in activity, or a lack of physical preparation are the most common causes.

Training errors account for 60% to 80% of overuse injuries in runners.⁴ The principle is simple: when the stress applied to the joint exceeds its recovery capacity, the tissues become irritated and pain appears. Studies show that increasing training volume by more than 10% per week is a documented risk factor.⁵

Think of your patellofemoral joint like a bank account: each activity represents a withdrawal, and rest allows for deposits. If you withdraw more than you deposit for several consecutive days, you end up in deficit. This is exactly what happens during an overload: your tissues don't have time to repair themselves between training sessions.

This overload can occur in several ways. A runner who goes from 20 to 40 kilometers per week in two weeks, a hiking enthusiast who does a long mountain descent without prior training, or a basketball player returning after several months off are all at risk. The key lies in gradual progression.

What are the risk factors for Patellofemoral Pain Syndrome?

Certain factors increase the risk of developing patellofemoral pain syndrome: growth spurts in adolescents, participation in sports with repetitive jumping or sprinting, and the male sex, which appears to be slightly more affected in the younger population.

The prevalence of patellofemoral pain syndrome reaches 22% to 40% among active adolescents.⁶ Growth spurts are a particular risk factor: the femur grows faster than the surrounding soft tissues, which creates increased tension on the joint.

Sports that involve repetitive jumping and sprinting also increase the risk. Weakness in the hip muscles, particularly the abductors, is another factor often identified during a physiotherapy assessment.

What are the symptoms of Patellofemoral Pain Syndrome?

Pain at the front of the knee is the main symptom of patellofemoral pain syndrome. It generally appears gradually and worsens during squats, climbing or descending stairs, running, and prolonged sitting.

The pain is often diffuse and difficult to pinpoint precisely.⁷ Patients typically describe it as "around" or "behind" the kneecap rather than at a specific point. A characteristic sign is pain that appears after 20-30 minutes of sitting, sometimes called "movie theater sign."

How is Patellofemoral Pain Syndrome diagnosed?

The diagnosis of patellofemoral pain syndrome is based on the patient's symptom history and a clinical examination performed by a healthcare professional. X-rays are generally not useful because they cannot visualize this type of tissue problem.⁸

A clinical evaluation includes a detailed analysis of your symptom history: when the pain started, what makes it worse, and what relieves it. Your physiotherapist also performs specific tests such as palpation of the kneecap facets and compression tests.

MRI is rarely necessary unless we suspect a structural injury such as a meniscal tear or a ligament injury. Patellofemoral pain syndrome is a clinical diagnosis that does not require expensive imaging. To learn more about another common knee condition, consult our guide on patellar tendon tendinopathy.

How does physiotherapy treat Patellofemoral Pain Syndrome?

Your physiotherapist assesses your joint mobility, the quality of your movements, and your muscle strength to identify the cause of your patellofemoral pain syndrome. Treatment includes mobilizations, strengthening exercises, and muscle control retraining.

Therapeutic exercise is the first-line treatment with strong scientific evidence.⁹ Studies show that combined knee and hip strengthening is superior to knee strengthening alone.^10 The success rate of conservative treatment reaches 80% to 90% of cases, with a typical treatment duration of 6 to 12 weeks.

Personalized treatment may include joint mobilizations to improve kneecap gliding, strengthening exercises targeting the quadriceps and gluteal muscles, as well as motor control retraining to optimize your movement patterns. Education on managing your activity levels is also an integral part of the treatment plan.

Why is hip strengthening so important?

Several studies have demonstrated the crucial importance of strengthening the hip muscles in treating patellofemoral pain syndrome. The gluteal muscles, particularly the gluteus medius, control the position of the thigh bone during movement. When these muscles are weak, the thigh bone tends to rotate inward, which increases pressure on the outer side of the kneecap.

This relationship between the hip and the knee explains why treatment should target the entire kinetic chain rather than just the knee. A program that combines hip and knee strengthening produces better results than one that only targets the quadriceps. This approach follows a gradual and structured progression, allowing tissues to adapt progressively to increasing loads.

Does Physiotherapy Work for Patellofemoral Pain Syndrome?

Physiotherapy is recognized as an effective treatment for patellofemoral pain syndrome, with results supported by scientific research.

Studies show a 75-85% success rate for treating patellofemoral pain syndrome with physiotherapy. The combination of therapeutic exercises, manual therapy, and education proves particularly effective in reducing pain and improving function.

The effectiveness of treatment depends on several factors: how early you seek consultation (earlier intervention often leads to better results), consistency with home exercises, quadriceps strength, muscle coordination, and knee biomechanics. A comprehensive evaluation allows for tailoring the treatment to your specific situation.

Most patients notice an improvement within the first 3-4 sessions, with complete resolution typically achieved in 8-12 weeks.

Are you suffering from patellofemoral pain syndrome? Book an appointment for a complete evaluation and a personalized treatment plan.

What exercises help relieve Patellofemoral Pain Syndrome?

Gluteal and quadriceps strengthening exercises are essential for treating patellofemoral pain syndrome. Cycling and swimming allow you to maintain physical activity without worsening symptoms during the recovery phase.

Strengthening the glute muscles is a cornerstone of the treatment. These muscles control knee alignment during everyday activities. A progressive exercise program helps restore the strength and muscle control needed to get back to your activities.

Progression generally occurs in three phases: first, static exercises with light cycling and swimming, then strengthening with partial weight, and finally a gradual return to your sports activities. Your physiotherapist will adapt this plan based on your progress.

How long does recovery take?

The duration of recovery varies depending on several factors: the severity of your symptoms, your activity level, and your consistency with the exercise program. In general, you can expect significant improvement after 6 to 8 weeks of physiotherapy treatment.

Some patients feel relief within the first few weeks, especially if the problem is addressed early. Others, particularly those who have been experiencing pain for several months, may need 12 to 16 weeks for a complete recovery. The key is to follow the program consistently and avoid resuming activities too quickly.

Patience is essential. Many patients make the mistake of resuming running or their sport as soon as the pain decreases. This approach often leads to a recurrence. Your physiotherapist will guide you in gradually returning to activities to minimize the risk of relapse.

Can You Treat Patellofemoral Pain Syndrome Yourself?

Self-treatment can relieve mild patellofemoral pain syndrome (ice, rest, gentle stretches). However, without a biomechanical analysis, you risk strengthening muscles in incorrect patterns that could worsen the problem. Without an accurate diagnosis, you might maintain compensations or perform counterproductive exercises that delay healing.

The physiotherapist analyzes knee biomechanics and corrects improper movement patterns. An evaluation helps identify the exact cause, rule out any red flags, and create a progressive treatment plan. Exercises are tailored to your specific condition, not generic.

Our approach: professional assessment + supervised home exercise program = better long-term results.

Are you hesitating between self-treatment and a consultation? Free 15-min consultation to discuss your situation.

When should you see a physiotherapist for patellofemoral pain syndrome?

Consult a physiotherapist if you have persistent pain at the front of your knee or if your symptoms don't improve after 10 days of self-management. In Quebec, you do not need a doctor's referral to see a physiotherapist.

Direct access to physiotherapy allows for quick care without waiting for a medical referral. If your condition requires further medical evaluation, your physiotherapist will be able to direct you to the appropriate professional.

The prognosis for patellofemoral pain syndrome is excellent with appropriate treatment. The vast majority of patients return to their normal activities after a well-managed rehabilitation program. The key to success lies in early intervention and an exercise program tailored to your specific condition.

• Crossley KM, et al. 2016 Patellofemoral pain consensus statement. Br J Sports Med. 2016;50(14):839-843.
• Powers CM. The influence of abnormal hip mechanics on knee injury. J Orthop Sports Phys Ther. 2010;40(2):42-51.
• Reilly DT, Martens M. Experimental analysis of the quadriceps muscle force and patello-femoral joint reaction force. J Bone Joint Surg Am. 1972;54(4):749-756.
• Nielsen RO, et al. Training errors and running related injuries. Int J Sports Phys Ther. 2012;7(1):58-75.
• Buist I, et al. Incidence and risk factors of running-related injuries. Am J Sports Med. 2010;38(2):273-280.
• Witvrouw E, et al. Intrinsic risk factors for the development of anterior knee pain. Am J Sports Med. 2000;28(4):480-489.
• Cook C, et al. Best tests/clinical findings for screening and diagnosis of patellofemoral pain. Int J Sports Phys Ther. 2012;7(2):144-152.
• Crossley KM, et al. Patellofemoral pain. Br J Sports Med. 2016;50(14):839-843.
• Collins NJ, et al. 2018 Consensus statement on exercise therapy. Br J Sports Med. 2018;52(18):1170-1178.
• Fukuda TY, et al. Hip posterolateral musculature strengthening in women with patellofemoral pain syndrome. J Orthop Sports Phys Ther. 2012;42(1):22-29.