Prepatellar bursitis is inflammation of a small fluid-filled sac (bursa) that sits in front of your kneecap (patella), between the skin and the patella. The bursa normally acts like a cushion and reduces friction when your skin moves over the kneecap. When it becomes irritated, it can fill with extra fluid and swell, creating a visible lump at the front of the knee and making kneeling and pressure on the kneecap very uncomfortable.
You might hear prepatellar bursitis called housemaid’s knee or carpet layer’s knee because it is strongly associated with frequent kneeling and pressure on the front of the knee. People who kneel for work (such as carpet layers, roofers, cleaners, gardeners, plumbers and miners) are repeatedly exposed to the friction and compression that can trigger inflammation.
Prepatellar bursitis can be aseptic (not infected) or septic (infected). This distinction matters because septic bursitis needs medical assessment and antibiotics, and sometimes aspiration (drawing fluid out with a needle). Aseptic bursitis is usually managed conservatively with activity modification, pressure reduction, and physiotherapy for prepatellar bursitis to restore comfortable movement and reduce recurrence risk.
Physiotherapists commonly help people with prepatellar bursitis in two situations:
- Early management when swelling and pain make kneeling, squatting and stairs difficult, and
- Prevention of recurrence for people whose work or sport involves kneeling and repetitive contact on the knee.
Your physiotherapist can also help identify signs that may indicate infection, prompting timely referral to a GP or emergency department when needed.
Key Facts
- Prepatellar bursitis is more common in occupations involving prolonged kneeling or leaning on the knees, and is often described in men aged 40–60 years in clinical summaries. 🔗
- The prepatellar bursa is the most commonly affected bursa in the knee, and the second most commonly affected bursa overall (after the olecranon bursa). 🔗
- A systematic review reports septic bursitis represents around one-third of all prepatellar bursitis cases, and Staphylococcus aureus is the most common pathogen in septic bursitis (around 80% in multiple studies). 🔗
Risk Factors
- Jobs that require frequent or prolonged kneeling, leaning on the knees, or working on hard floors.
- Sport or hobbies with repetitive contact on the knees (wrestling, some martial arts, frequent kneeling-based training, gardening).
- Recent minor trauma to the kneecap region (bump, fall, collision).
- Skin breaks, abrasions, or chronic rubbing over the kneecap (increases infection risk).
- Poor kneeling strategies, such as kneeling directly on the patella rather than distributing pressure through padding or positioning.
- Underlying inflammatory conditions (less common) that can predispose to bursitis in multiple areas.
Symptoms
- Swelling or a soft lump directly over the kneecap, sometimes described as a “golf ball” or “puffy kneecap”.
- Pain or tenderness at the front of the knee, especially when kneeling, crawling, or bumping the kneecap.
- Warmth or redness over the swelling (more concerning if rapidly worsening or spreading).
- A tight, stretched feeling of the skin at the front of the knee from fluid build-up.
- Pain with squatting, stairs, or getting up from the floor if the swelling limits comfortable knee bend.
- Reduced confidence kneeling at work, in sport, or with home tasks (gardening, cleaning).
- If infected: increasing pain, increasing redness, possible fever or feeling unwell, and the knee may look more inflamed and feel more tender.
Aggravating Factors
- Kneeling for long periods (flooring, cleaning, gardening, roofing, plumbing), especially on hard surfaces.
- Repeated pressure or friction on the front of the knee, including crawling or frequent transitions to kneeling.
- Direct knocks or minor trauma to the kneecap region (worksite bumps, sport contact, falls).
- Returning to kneeling tasks too quickly after symptoms settle, without addressing pressure and technique.
- Tight or irritated skin over the kneecap that is repeatedly rubbed, increasing infection risk if the skin breaks.
Causes
Prepatellar bursitis happens when the prepatellar bursa becomes irritated and inflamed. The most common driver is repeated compression and friction over the kneecap, particularly from prolonged kneeling. Clinical references consistently highlight occupational kneeling as a major contributor, which is why the condition is often linked to kneeling-based trades and roles.
It can also occur after a direct blow or minor trauma to the front of the knee. Even a small impact can cause bleeding or inflammation in the bursa, leading to swelling. This is sometimes called traumatic bursitis.
In some cases, the bursa becomes infected. This usually happens when bacteria enter through a small break in the skin (a scratch, abrasion, or cracked skin from friction). Septic bursitis is clinically important because it requires medical assessment and antibiotic treatment. A systematic review notes that septic bursitis represents around one-third of superficial bursitis cases involving the olecranon and prepatellar bursae, and Staphylococcus aureus is the most common pathogen.
From a physiotherapy perspective, prepatellar bursitis is often a load and pressure management problem. If your daily routine keeps compressing the bursa, it will keep flaring. Physiotherapy for prepatellar bursitis focuses on reducing pressure, changing kneeling mechanics, improving strength and control for kneeling transitions, and rebuilding tolerance for the tasks you actually need to do.
How Is It Diagnosed?
Prepatellar bursitis is usually identified through a clinical assessment. A physio will look for superficial swelling directly over the kneecap, assess tenderness, warmth and redness, and ask about factors that commonly trigger it such as repeated kneeling, recent impact, or increased time on the knees. They’ll also assess how symptoms respond to movement and pressure—prepatellar bursitis is typically most painful with kneeling, direct pressure, or compressive positions, whereas deeper joint problems are more likely to cause pain with twisting, locking, or joint line tenderness. Your physio will also screen for other potential causes of anterior knee swelling or pain (e.g., patellar tendon pain, joint effusion, gout, or cellulitis) and decide whether imaging or further assessment is needed. Importantly, physiotherapists will screen for signs of septic (infected) bursitis, such as rapidly increasing swelling, marked redness and heat, fever, feeling unwell, or spreading redness—if these are present, urgent medical review is recommended, as aspiration and antibiotics may be required.
Investigations & Imaging
- Ultrasound
- Can confirm fluid in the prepatellar bursa, help differentiate bursitis from a joint effusion, and guide clinical decisions when swelling is unclear or persistent.
- X-ray
- Not routinely required for simple bursitis, but may be used after trauma to rule out fracture, foreign body, or bony changes if symptoms are atypical or persistent.
- Aspiration
- Used when infection is suspected. Fluid can be analysed for infection and crystals, helping guide antibiotic treatment and exclude gout-like processes.
- Blood tests
- May support assessment for infection (inflammatory markers) or systemic contributors when presentation is concerning or recurrent.
Grading / Classification
- Aseptic prepatellar bursitis
- Inflammation without infection, often related to kneeling pressure or minor trauma. Swelling is usually localised and may be tender, but systemic symptoms (fever, unwellness) are absent.
- Septic prepatellar bursitis
- Infected bursa, often following a skin break or abrasion. Pain, warmth, redness and tenderness are typically more pronounced and may worsen rapidly. Fever or feeling unwell can occur. Requires urgent medical assessment and antibiotics.
- Acute versus chronic
- Acute bursitis develops over days after kneeling overload or a knock. Chronic bursitis persists or recurs over weeks to months, often because kneeling exposure continues or the bursa remains thickened and reactive.
Physiotherapy Management
Physiotherapy for prepatellar bursitis aims to reduce swelling and pain, restore comfortable knee bending and kneeling transitions, and stop the problem from coming back. Physiotherapy is most useful for aseptic prepatellar bursitis and for recovery after medical treatment of septic bursitis once infection is controlled.
The most important driver is usually pressure management. If your work or sport requires kneeling, your physiotherapist will help you reduce compression on the bursa while still getting tasks done. This often involves kneeling technique changes, frequent micro-breaks, kneeling aids, and work positioning strategies so you are not loading directly onto the kneecap.
Physiotherapists also address movement and strength factors that make kneeling more provocative. If your hip strength is poor, ankle mobility is limited, or your squat pattern forces you to drop onto the kneecap, the front of the knee can take repeated impact. Rehab improves control through the hips and legs so kneeling and floor transfers become smoother, quieter, and less compressive.
If swelling is large, your physiotherapist will guide ways to keep moving without flaring it, including temporary activity changes and advice on when to seek medical review. Importantly, physiotherapists watch for signs of possible infection. If the knee becomes increasingly red, hot, very tender, or you feel unwell, this needs medical assessment rather than pushing on with rehab.
Exercise
Physiotherapy exercises are chosen to keep the knee functional while reducing direct pressure on the bursa. Early on, you often do better with exercises that load the leg without kneeling on the patella.
Early phase: Your physiotherapist may focus on restoring comfortable knee range of motion (without forcing deep compression), maintaining walking tolerance, and building gentle strength through the quadriceps and hips. This often includes controlled sit-to-stand, step-ups in a comfortable range, and hip strengthening that improves lower limb control.
Strength and control phase: As swelling settles, exercises progress to more demanding squats, lunges and single-leg tasks, with careful attention to knee tracking and how you transition into and out of kneeling. A common goal is making floor transfers smoother so the knee is not repeatedly bumped or slammed onto the ground.
Kneeling tolerance progression: For people who must kneel for work, physiotherapy includes a graded kneeling plan. This might begin with brief kneeling on thick padding, distributing pressure through the shin and thigh rather than directly onto the patella, then gradually increasing time and task complexity as the bursa tolerates it. The best outcomes usually come from combining exercise with real-world technique and equipment changes rather than relying on exercise alone.
Exercises are always adjusted if swelling increases or the knee becomes more painful the next day. The aim is consistent progress without repeated flare-ups.
Activity Modification
Activity modification is central to recovery because prepatellar bursitis is usually triggered by repeated kneeling pressure. The goal is to keep you active while stopping the specific compression that keeps refilling the bursa.
Your physiotherapist will help you identify your biggest triggers: kneeling on hard floors, crawling, kneeling without padding, or frequent up-down transitions. Practical strategies include using high-quality knee pads, kneeling on foam mats, changing task setup to reduce time on the knees, alternating tasks, and using a stool or low seat where possible.
If your job requires unavoidable kneeling, your physio can help you plan a staged return to kneeling tasks so you do not go from “no kneeling” to “eight hours kneeling” in one week. This pacing approach is one of the most important parts of prepatellar bursitis rehab.
Manual Therapy
Manual therapy is not the main treatment for prepatellar bursitis, but it can help when movement restrictions elsewhere are increasing stress at the knee. For example, limited ankle mobility can force a knee-forward squat that increases anterior knee pressure during daily tasks. A physiotherapist may use manual techniques to improve ankle, hip, or knee mobility so you can move with less front-of-knee compression.
Manual therapy can also be useful for surrounding soft tissue tightness if it helps you tolerate strengthening and improves movement quality. It is always paired with exercises and technique changes, because pressure reduction is the key driver of improvement.
Bracing & Taping
Bracing is not routinely required for prepatellar bursitis, but some people benefit from compression to help manage swelling and provide comfort during walking and work. A physiotherapist may recommend a compressive sleeve or wrap if it reduces swelling without causing irritation.
Protective padding is often more useful than bracing. Quality knee pads and kneeling mats reduce direct pressure on the bursa, which is essential if kneeling cannot be avoided.
Taping may occasionally be used to support swelling control or reduce irritation from rubbing, but it is considered an adjunct to activity modification, not a primary treatment.
Heat & Ice
Ice can help reduce pain and swelling in the early stages of aseptic prepatellar bursitis, particularly after a day that involved unavoidable kneeling or repeated knee bending. A physiotherapist may recommend short, regular ice applications if you find it helps symptoms settle.
Heat is less commonly used for bursitis swelling, but it may help if surrounding muscles are tight and warmth improves comfortable movement before exercise. The key is to avoid heat if the knee is very hot, red, or infection is suspected.
Education
Education is one of the most valuable parts of physiotherapy for prepatellar bursitis because recurrence is common when kneeling exposure continues. Your physiotherapist will explain what the bursa does, why it swells with compression, and why reducing direct patellar pressure is non-negotiable during flare-ups.
Education is also about recognising infection risk. If your bursa swelling becomes increasingly red, hot and tender, if redness spreads, or if you develop fever or feel unwell, your physiotherapist will advise urgent medical review because septic bursitis needs antibiotics and sometimes aspiration. Clinical guidance recommends aspiration and empiric antibiotics when septic bursitis is suspected.
For work-related cases, education includes knee pad selection, mat setup, task rotation, pacing, and kneeling technique changes so you can keep working while reducing the chance of repeated flare-ups.
Other
Other important aspects of management often include:
Worksite and ergonomic planning: For trades and roles that require kneeling, physiotherapists can help plan realistic changes such as using stools, changing the height of the work surface, rotating tasks, and scheduling kneeling-heavy work in shorter blocks.
Return-to-kneeling program: A planned progression back to kneeling is often the difference between full recovery and recurring swelling. This includes graded exposure, quality padding, and movement retraining for floor transfers.
Referral pathways: If bursitis is recurrent, unusually painful, or suspicious for infection, gout, or another systemic issue, your physiotherapist can coordinate with your GP for medical assessment and further investigations.
Other Treatments
Other treatments depend on whether the bursitis is aseptic or septic:
Medical management for suspected septic bursitis: Clinical guidance recommends aspiration (where possible) and empiric antibiotics covering staphylococci and streptococci while awaiting culture results.
Aspiration for symptom relief: In selected aseptic cases, clinicians may aspirate the bursa to reduce swelling, but recurrence can occur if kneeling pressure continues. Aspiration decisions are made by medical professionals based on clinical context and infection risk.
Compression and protection: Compression and protective knee padding can reduce swelling and prevent repeated irritation, particularly in occupational cases.
Medication: Short-term pain relief or anti-inflammatory medication may be used for symptom control, guided by your GP or pharmacist. Medication should not be used to push through prolonged kneeling while the bursa remains reactive.
Surgery
Surgery is rarely needed for prepatellar bursitis. It is generally considered only when symptoms are persistent and significantly limiting despite appropriate conservative management, or when recurrent infection or repeated fluid re-accumulation does not respond to medical treatment.
When surgery is performed, it may involve bursectomy (removal of the inflamed bursa). After surgery, physiotherapy is important to restore knee range of motion, rebuild strength, manage swelling, and guide a safe return to kneeling tasks with better pressure management strategies.
Prognosis & Return to Activity
Most cases of aseptic prepatellar bursitis improve with conservative management, particularly when direct kneeling pressure is reduced and a physiotherapy program restores comfortable movement and strength. Recovery time varies from days to weeks depending on the size of the swelling, how effectively pressure is reduced, and whether kneeling exposure continues.
When the bursitis is work-related and kneeling cannot be fully avoided, prognosis improves significantly with strong activity modification strategies (knee pads, kneeling mats, task rotation) plus progressive strengthening and movement retraining through physiotherapy.
Septic bursitis often improves with appropriate medical treatment, but it requires prompt assessment. A systematic review notes Staphylococcus aureus is the most common organism in septic bursitis and septic cases form a meaningful subset of superficial bursitis presentations, reinforcing why red flags should be taken seriously.
Return to kneeling and sport should be guided by swelling response and the ability to kneel briefly on padding without next-day flare-up. Physiotherapists help plan this progression so symptoms do not keep returning.
Complications
- Recurrent swelling if kneeling pressure continues and the bursa remains irritated.
- Septic bursitis (infection), particularly if there are skin breaks, abrasions, or repeated rubbing over the kneecap.
- Reduced knee bending tolerance and altered movement patterns (avoiding squats or kneeling) that can lead to deconditioning.
- Skin irritation, blistering, or callus from ongoing kneeling that perpetuates the cycle of inflammation.
Preventing Recurrence
- Use high-quality knee pads and kneeling mats for any regular kneeling tasks to reduce direct compression of the prepatellar bursa.
- Change kneeling technique by distributing load through the shin and thigh where possible, rather than resting directly on the kneecap.
- Rotate tasks and use pacing strategies so kneeling time is broken into shorter blocks, preventing bursa re-irritation on long workdays.
- Maintain hip and leg strength and control with a physiotherapy-guided program so floor transfers, squatting and kneeling are smoother and less compressive.
When to See a Physio
- You have a new swollen lump over the kneecap, especially after kneeling work or a direct knock.
- Your knee is increasingly red, hot, very tender, or the redness is spreading, as these features can suggest infection.
- You have fever or feel unwell alongside knee swelling.
- Swelling keeps returning when you return to kneeling tasks and you need a prevention-focused rehab plan.
- Kneeling is essential for your job and you need practical strategies, knee pad advice, and a graded return-to-kneeling program.
- You have persistent swelling or pain despite several weeks of self-management and want assessment to rule out other causes.