Patellofemoral Stress Syndrome

Patellofemoral stress syndrome — better known as “runner’s knee” — is aching pain around or behind the kneecap that flares with running, stairs, squatting, or long sitting. It’s very common and highly treatable, usually without surgery. Our orthopedic and sports medicine team treats it across Long Island and northern New Jersey, with offices in Plainview, New Hyde Park, and Ronkonkoma, NY, and Clifton, Montville, and Plainfield, NJ.

What patellofemoral syndrome is

Your kneecap glides in a groove at the end of the thigh bone as you bend and straighten the knee. When that tracking is off, or the joint is simply overloaded, the tissue around the kneecap gets irritated and painful. Because it’s not a single structural injury but a pattern of overload, it’s usually treated by changing the forces on the kneecap rather than by surgery.

Contributing factors include muscle imbalance or weakness (especially in the hips and thighs), a sudden increase in training, and biomechanics like how your foot and leg align during activity.

Symptoms

• A dull, aching pain around or behind the kneecap
• Pain that worsens with stairs, squatting, kneeling, or running
• Discomfort after sitting for a long time with the knee bent (the “theater sign”)
• Sometimes a grinding or clicking sensation in the kneecap

How patellofemoral syndrome is treated

The foundation is conservative, and it works well for most people:

• Physical therapy — strengthening the hips, quadriceps, and core to improve how the kneecap tracks is the single most effective treatment.
• Activity modification — temporarily reducing high-impact activity and building back gradually.
• Supportive measures — taping, bracing, proper footwear, or orthotics where alignment is a factor.
• Ice and anti-inflammatories — to manage pain during flares.

Are you a candidate for treatment?

It’s worth being evaluated when:

• You have ongoing front-knee pain with stairs, squatting, or activity
• Home care and rest haven’t resolved it
• The pain keeps returning when you get back to running or sport
• You want a plan to fix the underlying cause, not just the symptoms

Related conditions

If your pain is specifically in the tendon just below the kneecap rather than around it, see our patellar tendonitis page, or return to our knee pain overview.

Why patients across Long Island and North Jersey choose Empire

Insurance

Coverage varies by plan and by location, and we accept many major insurance plans across our New York and New Jersey offices. The simplest way to know exactly what your plan covers is to call — our team will verify your benefits before your visit, so there are no surprises. Whether you’re on Long Island or in North Jersey, reach out and we’ll walk you through your options.

Frequently asked questions

What causes runner’s knee?

It’s usually a combination of overload and how the kneecap tracks — often linked to muscle imbalance or weakness in the hips and thighs, a spike in training, or biomechanics. It’s rarely a single structural injury.

How is it treated?

Mainly with physical therapy to strengthen the hips and thighs, plus activity changes and supportive measures. This resolves the large majority of cases.

Do I need surgery?

Almost never. Patellofemoral syndrome responds to conservative care in nearly all cases. Surgery is a rare last resort for specific structural problems.

Can I keep running?

Often you can continue some activity while reducing the load that flares it, then build back gradually. Your therapist will help you find the right balance.

Why does my knee hurt after sitting?

Sitting with the knee bent for a long time loads the kneecap, which is why pain after a movie or long drive — the “theater sign” — is a classic feature of this condition.

How long until it gets better?

Many people improve within several weeks of consistent therapy, though it varies. Sticking with the strengthening program is what makes the improvement last.