Runner’s Knee, also known as Patellofemoral Pain Syndrome (PFPS), is a common source of discomfort among active individuals, especially those who run, hike or engage in sports that involve repeated knee bending.

Although often associated with athletes, it can also affect individuals who spend long hours on their feet, have muscular imbalances, or are returning to exercise after a prolonged break. This condition is one of the most common causes of knee pain in active individuals in Singapore, especially those seeking treatment for Runner’s Knee.

The pain typically starts as a dull ache around the kneecap and may gradually intensify during physical activity. Some people feel a sensation of pressure or “grinding” behind the knee when climbing stairs or standing up after sitting for a long period.

While the condition may sound minor at first, untreated Runner’s Knee can become persistent and eventually limit daily movement, training progress and overall quality of life.

What causes Runner’s Knee?

The pain develops when the kneecap is subjected to prolonged strain or abnormal movement patterns. Some of the factors that may contribute include:

• Increased pressure on the patellofemoral joint – excessive pressure on the patellofemoral joint often leads to knee pain when bending, particularly during repetitive activities like running or squatting. When the volume or intensity of these activities rises too quickly, the joint surfaces become irritated and inflamed.

• Maltracking of the kneecap – if the patella does not glide centrally within its groove, certain areas of cartilage experience higher stress. This uneven movement, called “maltracking,” leads to discomfort, pressure and sometimes a grinding sensation.

• Irritation of the surrounding soft tissues – the tissues around the patella, including the retinaculum and fat pad, can become inflamed when repeatedly compressed. This contributes to sharp, localised pain at the front of the knee.

• Overloading of the cartilage – although cartilage has no nerves, prolonged overloading can cause swelling within the bone beneath it, producing a deep, aching pain known as bone stress.

• Reduced shock absorption – when muscles around the knee and hips fatigue or fail to absorb impact effectively, more force passes directly into the knee joint. This increases strain on the patellofemoral compartment and worsens symptoms.

What are the symptoms of Runner’s Knee?

The symptoms can present differently depending on severity, activity level and underlying biomechanics. But generally, it consists of:

• Pain around or behind the kneecap – typically described as a dull, aching discomfort that worsens during activities involving knee bending.

• Pain during running – many patients describe pain around the kneecap when running, especially during longer distances or downhill routes, where stress on the patellofemoral joint increases.

• Front knee pain when climbing stairs or squatting – activities such as squatting or climbing stairs often trigger discomfort, and many individuals report front knee pain when climbing stairs or standing up after sitting.

• Discomfort after prolonged sitting – also known as “movie sign” or “theatre sign”, where the knee feels stiff or sore when rising after sitting with bent knees for long periods.

• Clicking, popping or grinding sensations – some patients notice noises or a feeling of friction when bending the knee, especially during squats or stair use.

• Knee stiffness after rest or inactivity – the knee may feel tight or difficult to move smoothly after a period of inactivity.

• Swelling or puffiness around the kneecap – mild swelling may develop when the tissues become inflamed or irritated.

Who is at risk of Runner’s Knee?

Runner’s Knee can affect anyone, but certain factors increase your likelihood of developing the condition. These do not directly cause the pain, but they can create an environment where the patellofemoral joint becomes more easily irritated.

Some of the factors that increase the risk of developing the pain are:

• Active individuals – people who run frequently or participate in high-impact sports place repeated stress on the kneecap. Over time, this continual stress can make the tissues around the patella more sensitive, especially if training is not balanced with adequate recovery.

• A recent increase in training load – a sudden jump in distance, speed or frequency may overwhelm your knee’s ability to adapt. Without gradual progression, the patellofemoral joint and surrounding soft tissues may become irritated more quickly.

• Weak hip, thigh or gluteal muscles – under-conditioned muscle groups provide less control during movement, making the patella more likely to drift slightly out of its ideal track.

• Flat feet or excessive pronation – certain foot shapes can affect the biomechanics of the entire leg. When the foot rolls inward excessively, the knee may tilt or rotate inward as well, increasing strain on the patellofemoral joint with each step.

• Previous knee injury – past ligament, cartilage or patellar injuries may alter your knee mechanics. Even after healing, subtle imbalances can persist, raising the risk of developing front-of-knee pain during exercise or daily activities.

• Long hours sitting – sitting with bent knees for extended periods, tighten the structures around the patella. This can lead to stiffness or discomfort when standing up or returning to activity.

• Using improper footwear – worn-out shoes or footwear without cushioning reduces shock absorption. As a result, more impact travels to the knee, increasing irritation during walking, running or prolonged standing.

How is Runner’s Knee diagnosed in Singapore?

A careful and structured assessment is essential for confirming Runner’s Knee and distinguishing it from other causes. The process typically entails:

• History taking – our doctor will begin by asking when the pain started, what activities worsen or ease the discomfort and whether the symptoms appeared gradually or after a specific event. You may also be asked about your training habits, footwear, changes in activity level and any previous knee injuries, as these details often provide important clues.

• Physical examination – a thorough knee assessment is performed to check alignment, swelling and tenderness. Our doctor will also examine how the kneecap moves, test the strength of surrounding muscles and assess the flexibility of the quadriceps, hamstrings and hips.

• Movement and gait analysis – how you walk, squat or run may reveal hidden biomechanical issues. Our doctor may observe simple movements to see how the knee behaves during activity, helping pinpoint factors contributing to patellar irritation.

• Imaging tests – imaging may be recommended if symptoms persist or if structural damage needs to be excluded. This can include:
  • X-rays – help assess bone alignment and exclude conditions such as arthritis or fractures.
  • Magnetic resonance imaging (MRI) scans – provide detailed images of cartilage, tendons and soft tissues, offering deeper insight when needed.

How is Runner’s Knee treated in Singapore?

Most patients recover well with targeted, non-surgical care aimed at reducing irritation around the kneecap and restoring proper knee mechanics. The treatment typically involves a combination of the following:

Conservative Treatments

• Pain-relief medication – anti-inflammatory medicines may be prescribed short-term to settle discomfort, especially during flare-ups or after strenuous activity.
• Ice and swelling control – applying ice after exercise helps calm irritation and reduce mild swelling around the kneecap.
• Activity modification – reducing running mileage, switching temporarily to low-impact exercise or adjusting training surfaces helps relieve stress on the patellofemoral joint so healing can begin.
• Footwear and gait adjustments – running shoes with proper cushioning and support reduce load on the knee. Our doctor may advise changes in running technique to minimise impact forces.

Non-surgical Interventions

• Patellar braces or taping – these help guide the kneecap into a more stable position during movement, reducing discomfort during running, squatting or stair climbing.
• Shockwave therapy (ESWT) – useful for persistent cases, shockwave therapy stimulates tissue recovery, improves circulation and reduces chronic irritation around the tendon or kneecap.
• Platelet-Rich Plasma (PRP) injections – PRP may be recommended if symptoms remain despite consistent therapy. It delivers growth factors that support the healing of irritated soft tissues around the knee.

Surgical Interventions

• Lateral release or soft-tissue balancing – if tight surrounding tissues are pulling the kneecap out of alignment, selective release can improve patellar tracking.
• Cartilage smoothing or debridement – in cases of significant cartilage irritation or fraying behind the kneecap, minimally invasive techniques may be used to reduce mechanical rubbing.
• Realignment procedures – for severe maltracking or recurrent instability, realignment of the patellar tendon attachment or corrective bone procedures may be recommended to restore proper joint mechanics.

Rehabilitation and Physiotherapy

• Physiotherapy and strengthening – focused rehabilitation is central to recovery. The programmes often include quadriceps and hip strengthening, patellar tracking exercises, taping techniques and flexibility work to correct the underlying biomechanical issues.

When to see a Knee Specialist in Singapore

If knee pain is affecting your mobility, comfort or ability to stay active, it is important to have it assessed early. Prompt evaluation helps identify the underlying cause, prevents worsening symptoms and allows you to return to your usual activities with confidence.

Book an appointment with Dr James Tan for a personalised knee assessment and a PFPS treatment in Singapore tailored to your lifestyle, activity level and recovery goals. Remember that early care often means faster recovery and fewer long-term issues.