Patellofemoral syndrome

Patellofemoral 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 people and athletes who increase their training volume too quickly. As physical therapists 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 take a look at what causes this pain and how you can get rid of it.

What is patellofemoral syndrome?

Patellofemoral syndrome is pain in the front of the knee caused by excessive stress between the kneecap and the thighbone. This condition occurs when the joint is subjected to mechanical stress that exceeds its ability to adapt.

The patella, the triangular bone at the front of the knee, plays an essential role in movement. It acts as a pulley for the quadriceps muscle and increases its lever arm by 30 to 50%, allowing the muscle to develop more strength^.

What is the role of the patella in the knee?

The patella is a sesamoid bone because it is located inside the quadriceps tendon. This particular position allows it to facilitate the sliding of the tendon during knee flexion and extension movements.

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

What causes patellofemoral syndrome?

Patellofemoral syndrome is caused by mechanical overload on the patella-femur joint. The most common causes are too rapid an increase in training volume, a change in activity, or a lack of physical preparation.

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

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

This overload can occur in several ways. A runner who increases their mileage from 20 to 40 kilometers per week in two weeks, a hiker who takes a long mountain descent without prior training, or a basketball player who returns to play after several months off are all at risk. The key is to take it slowly.

What are the risk factors for patellofemoral syndrome?

Certain factors increase the risk of developing patellofemoral syndrome: growth spurts in adolescents, participating in sports involving repetitive jumping or sprinting, and being male, which seems to be slightly more prevalent in the young population.

The prevalence of patellofemoral syndrome reaches 22 to 40% in active adolescents.⁶ Growth spurts are a particular risk factor: the femur grows faster than the surrounding soft tissues, creating 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 physical therapy assessment.

What are the symptoms of patellofemoral syndrome?

Pain in the front of the knee is the main symptom of patellofemoral syndrome. It usually develops gradually and worsens during squats, climbing or descending stairs, running, and prolonged sitting.

The pain is often diffuse and difficult to locate precisely^.7 Patients typically describe it as being "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 referred to as the "movie theater sign."

How is patellofemoral syndrome diagnosed?

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

The clinical assessment includes a detailed analysis of your symptoms: when the pain started, what makes it worse, and what relieves it. Your physical therapist will also perform specific tests such as palpation of the patella facets and compression tests.

An MRI is rarely necessary unless we suspect a structural injury such as a meniscus tear or ligament injury. Patellofemoral syndrome is a clinical diagnosis that does not require costly imaging. To learn more about another common knee condition, see our guide to patellar tendon tendinopathy.

How does physical therapy treat patellofemoral syndrome?

Your physical therapist will assess your joint mobility, range of motion, and muscle strength to identify the cause of your patellofemoral syndrome. Treatment includes mobilization, strengthening exercises, and motor control retraining.

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

Personalized treatment may include joint mobilization to improve patellar gliding, strengthening exercises targeting the quadriceps and gluteal muscles, and motor control rehabilitation to optimize your movement. Education on how to pace your activities 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 the treatment of patellofemoral syndrome. The gluteal muscles, particularly the gluteus medius, control the position of the femur during movement. When these muscles are weak, the femur tends to rotate inward, which increases pressure on the outer side of the kneecap.

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

Does Physical Therapy Work for Patellofemoral Syndrome?

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

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

The effectiveness of treatment depends on several factors: how early you seek consultation (earlier = better results), how diligently you do your exercises at home, the strength of your quadriceps, neuromuscular control, and the biomechanics of your knee. A comprehensive assessment allows us to tailor treatment to your specific situation.

Most patients see improvement within the first 3-4 weeks of treatment, with complete resolution within 8-12 weeks.

Do you suffer from patellofemoral syndrome? Make an appointment for a comprehensive evaluation and personalized treatment plan.

What exercises help relieve patellofemoral syndrome?

Exercises that strengthen the glutes and quadriceps are essential for treating patellofemoral syndrome. Cycling and swimming allow you to maintain your physical activity without aggravating symptoms during the recovery phase.

Strengthening the gluteal muscles is the cornerstone of treatment. These muscles control knee alignment during functional activities. A progressive exercise program helps restore the strength and motor control needed to return to activities.

Progression generally occurs in three phases: first, isometric exercises with light cycling and swimming, then strengthening with partial weight bearing, and finally a gradual return to your sporting activities. Your physical therapist will adapt this protocol according to your progress.

How long does recovery take?

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

Some patients feel relief within the first few weeks, especially if we catch the problem early. Others, especially those who have been suffering for several months, may need 12 to 16 weeks for a full recovery. The important thing is to follow the program regularly and not resume activities too quickly.

Patience is essential. Many patients make the mistake of resuming running or their sport as soon as the pain subsides. This approach often leads to a relapse. Your physical therapist will guide you through a gradual return to activities to minimize the risk of relapse.

Can you treat patellofemoral syndrome yourself?

Self-treatment can relieve mild patellofemoral syndrome (ice, rest, light stretching). However, without biomechanical analysis, you risk reinforcing bad patterns that aggravate the problem. Without an accurate diagnosis, you risk maintaining compensations or doing counterproductive exercises that delay healing.

The physical therapist analyzes the biomechanics of the knee and corrects deficient movement patterns. An assessment identifies the exact cause, eliminates red flags, and creates a progressive treatment plan. The exercises are tailored to your specific condition, not generic.

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

Are you unsure whether to self-treat or seek medical advice? Free 15-minute consultation to discuss your situation.

When should you see a physical therapist for patellofemoral syndrome?

Consult a physical therapist if you have persistent pain in the front of your knee or if your symptoms do not improve after 10 days of self-management. You do not need to see a doctor before consulting a physical therapist in Quebec.

Direct access to physical therapy allows for prompt treatment without waiting for a medical referral. If your condition requires further medical evaluation, your physical therapist will be able to refer you to the appropriate professional.

The prognosis for patellofemoral syndrome is excellent with appropriate treatment. The vast majority of patients return to their normal activities after a well-conducted rehabilitation program. The key to success lies in early treatment and an exercise program tailored to your 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 patellofemoral joint reaction force. J Bone Joint Surg Am. 1972;54(4):749-756.
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• Buist I, et al. Incidence and risk factors of running-related injuries. Am J Sports Med. 2010;38(2):273-280.
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• Collins NJ, et al. 2018 Consensus statement on exercise therapy. Br J Sports Med. 2018;52(18):1170-1178.
• Fukuda TY, et al. Strengthening the posterolateral hip musculature in women with patellofemoral pain syndrome. J Orthop Sports Phys Ther. 2012;42(1):22-29.