Written by Fairuuz Saleh, Principal Physiotherapist at Phoenix Rehab, AHPC A1301092H.Clinically reviewed by Louise Yow, Principal Physiotherapist & Director, AHPC A1300363H.Last reviewed 7 October 2026.
Prepatellar bursitis, often called housemaid’s knee, is a swollen fluid sac in front of the kneecap, usually from kneeling or a fall onto the knee. It feels like a soft, squashy lump over the kneecap. A hot, red, spreading swelling, a fever, or a cut over it can mean infection and needs a doctor the same day.
Key takeaways
- Prepatellar bursitis is a swollen fluid sac that sits between the skin and the kneecap, outside the knee joint.
- Kneeling is the usual cause: tiling, cleaning, plumbing, gardening, praying, wrestling and jiu-jitsu. A fall onto the kneecap can cause it too.
- A hot, red swelling over the kneecap, a cut or graze over it, or a fever needs a doctor the same day. Fever with spreading redness, or feeling unwell, needs the emergency department now.
- Whether to draw off the fluid, give antibiotics or operate is a decision for your doctor or surgeon.
- Rest settles the swelling. Kneeling comes back when it is trained back and timed on the surface you kneel on.
What is housemaid’s knee?
A bursa is a thin, flat sac with a little fluid inside. It lets the skin slide over the kneecap when you bend. The prepatellar bursa sits right on the front of the kneecap, under the skin. Press on it all day against a floor and it fills with fluid. That is prepatellar bursitis. The old names come from the jobs: housemaid’s knee, carpet layer’s knee, tiler’s knee.
The swelling sits in front of the kneecap, not inside the knee. That is why the knee often still bends, and why a swollen knee joint is a different problem, covered below. The same thing happens at the point of the elbow, covered in olecranon bursitis.
How common is it in people who kneel for work?
In one study, ultrasound scans found a thickened bursa at the front of the knee in 49% of 96 carpet and floor layers, against 7% of house painters, who work standing. Fluid in the bursa went with knee pain when kneeling.1
How it happens, in the order to check
1. Kneeling at work
The tiler on a bathroom floor all day. The cleaner scrubbing toilet bases. The plumber under a sink, the electrician at a floor socket, the carpet layer, the gardener at a planter bed. Each kneels on the same spot of the same knee, hour after hour. See construction worker injuries and work injuries, by job.
2. Kneeling to pray or to train
Prayer on a thin mat, several times a day. Wrestling and jiu-jitsu, with knee slides and long rounds on the knees. In volleyball, every dive for a low ball lands on the kneecaps.
3. A fall onto the knee
A trip on the stairs, a slip on a wet floor, a knee hitting the court. The bursa can fill with blood and swell within hours. A fall hard enough to swell the bursa can also crack the kneecap, so check the red flags below first.
4. A cut, a graze or a bite over the kneecap
Bacteria can get into the bursa through broken skin. Then the swelling turns hot, red and painful. This is septic bursitis, and it is a doctor’s job first. In a review of studies on bursitis at the kneecap and the elbow, about one case in three was infected, and 80% of patients were men, most aged 40 to 60.2
Prepatellar bursitis, an infected bursa, a swollen knee joint, gout or a broken kneecap?
Ask three things: where does the swelling sit, is it hot, and can you still bend the knee.
| Condition | Where the swelling sits | What you notice | What it needs first |
|---|---|---|---|
| Prepatellar bursitis (housemaid’s knee) | A soft lump on the front of the kneecap | Squashy to press, sore to kneel on. The knee usually still bends, tight at the end | Take the pressure off, then a physiotherapist |
| Infected (septic) bursitis | The same place | Hot, red and painful to touch, the redness spreading, often with a cut or graze over it, sometimes with a fever | A doctor the same day. Fever with spreading redness: the emergency department now |
| Swelling below the kneecap (infrapatellar bursitis) | Below the kneecap, over the tendon | A soft lump below the kneecap, from kneeling upright. See patellar tendon pain if it is the tendon that hurts | Take the pressure off, then a physiotherapist |
| Swelling inside the knee joint (effusion) | The whole knee | The dips either side of the kneecap fill in, and the knee will not bend or straighten fully. Often after a twist: meniscus or ACL | A doctor. A hot, swollen whole knee with a fever: the emergency department now |
| Broken kneecap (patella fracture) | Over the kneecap, after a fall onto it | Pain on any pressure. You cannot lift the straight leg off the bed, or cannot stand on it | The emergency department now |
| Gout | The joint, and sometimes the bursa | A hot, red, very painful knee that comes on over hours, often overnight, often with past attacks in the big toe | A doctor the same day |
| A knee that locks | Inside the joint | The knee catches or sticks in one position, then frees, or will not straighten. The bursa does not do this | A doctor. Locked and will not straighten: the same day |
Does prepatellar bursitis go away?
Often, once the kneeling stops. A bursa that is not infected usually settles over a few weeks with the pressure off. The swelling often comes back when the same kneeling starts again on the same knee, on the same floor, without pads. Some people are left with a thickened, rubbery pad over the kneecap that does not hurt. An infected bursa is different: it needs a doctor before anything else.
Prepatellar bursitis treatment: who does what
- A doctor (your GP, a polyclinic doctor or the emergency department) examines the knee and decides whether the bursa is infected. Whether to draw the fluid off with a needle and test it, whether to give antibiotics, and whether you need an X-ray or a scan are your doctor’s decisions.
- An orthopedic surgeon sees the bursa that will not settle, keeps coming back, or is infected and needs draining. Whether to drain it or remove it in an operation is your surgeon’s decision.
- A physiotherapist works out why that knee takes the pressure, takes the load off it, sets up pads and surfaces, trains the thigh and the bend, and builds kneeling back in timed steps until you can do your job, your training or your prayers on it.
Kneeling again, in stages
In the Phoenix Recovery Protocol the work starts at Calm & Protect: the pressure off the kneecap, the skin checked, the swelling measured. Move & Mobilize brings back the full bend and teaches you to get down to the floor and up again without landing on the sore spot. Rebuild & Strengthen trains the thigh, the hip and one-leg control, so the knee is not your only way down. Return & Perform times kneeling on the surface you use, with the pads you will wear: a bathroom floor, a prayer mat, a training mat. The test is kneeling and getting up for the length of a typical task without pain or swelling the next day.
After an operation to drain or remove the bursa, the same stages run to your surgeon’s protocol. See physiotherapy after surgery.
What we measure
- Swelling. A tape around the knee across the middle of the kneecap, against the other knee, week to week.
- The skin. Cuts, grazes, warmth and redness, checked each visit. Anything that looks infected goes back to your doctor.
- Knee bend. How far the knee bends, in degrees, against the other knee, and how close the heel gets to the buttock.
- Thigh strength. Rising from a low chair on one leg, counted on each side, and a slow step down from a stair without the knee falling in.
- Getting down and up. From standing to the floor and back, and which knee you land on.
- Kneeling time. How many minutes you can kneel on a padded surface, then on your work or training surface, before it aches, and whether it swells the next day.
Tested, not dated. The plan moves on when the measures say so.
What you can do this week
- Look at the skin over the kneecap. If there is a cut, a graze or a bite, or the swelling is hot and red, see a doctor the same day.
- Stop kneeling on that knee. Kneel on the other knee, sit on a low stool, or go down on one knee with the sore knee up.
- When you have to kneel, wear knee pads or kneel on a thick mat, every time.
- A cold pack wrapped in a cloth over the swelling for 10 to 15 minutes can ease the ache.
- Do not squeeze the lump, and do not try to drain it with a needle.
- Keep the knee moving: bend and straighten it within comfort, and tighten the thigh muscle with the leg straight, holding for a few seconds, several times a day.
- Pain relief and anti-inflammatory medication are a decision for your doctor or pharmacist.
Is this normal?
Usually expected: a soft, cool lump over the kneecap that is sore to kneel on and a little sore to press. Tightness at the end of the bend. Swelling that goes down week by week once you stop kneeling on it. A thickened, painless pad that stays after the swelling has gone. After a fall onto the knee, bruising that spreads down the shin over a few days.
Worth getting checked: swelling that comes back each time you kneel. Swelling that has not gone down after two to three weeks off the knee. Kneeling that stops you working, training or praying the way you did.
When to see a doctor first
- Call 995 if someone with a hot, swollen knee becomes confused, faints, is breathing fast, or has cold, blotchy skin. Also after a fall if bone is showing through a wound, or a wound is bleeding heavily and firm pressure does not slow it.
- Go to the emergency department now if you have a fever or chills with redness spreading from the knee, if you feel unwell with a hot, swollen knee, or if red streaks run up the thigh. Also for a whole knee joint that is hot, swollen and too painful to bend, with a fever. Also after a fall onto the knee if you cannot stand on the leg, cannot lift the straight leg off the bed, or have a deep cut over the kneecap.
- See a doctor the same day for a hot, red, tender swelling over the kneecap without a fever, a cut, graze or bite over the swelling, or swelling over the kneecap if you have diabetes or take medication that lowers your immunity. Also for a knee that turns hot, red and very painful over hours, and a knee locked bent that will not straighten.
- See a doctor soon for swelling that has not gone down after two to three weeks off the knee, swelling that keeps coming back, a lump that feels hard or keeps growing without kneeling, or a knee that catches or locks and then frees.
Where are you with this right now?
1. You stopped kneeling, and it is going down
The lump is cool, it is smaller each week, and you can bend the knee. The pads are in the van now, or there is a thicker mat by the prayer corner. That is a bursa behaving as expected. Keep the pads, keep the knee moving, and go back to kneeling a little at a time. You do not need us for this, and we would rather say so.
2. It goes down, and it comes back
You took a week off the floor and the swelling went. On the second day back on a bathroom job, the lump was there again by lunch.
Now you kneel on the other knee, the one that never had to do it, and that one has started to ache. You turned down the job with the most floor tiles. At training you sit out the rounds that start on the knees. When you pray, you lower yourself onto the bad knee and take the weight off it as fast as you can.
Resting it made sense while it was hot and full. In your own weeks since, rest has taken the swelling down and kneeling has brought it back, every time.
The swelling has gone. Has anyone timed how long you can kneel?
If the lump is hot, red or getting bigger, see your doctor first. If your doctor is happy that it is not infected, one Assessment & Treatment with a physiotherapist measures the swelling, the bend, the thigh and your kneeling time against the other knee, treats what is limiting you in the same visit, and tells you which stage you are in.
3. It has been drained or removed, or you have a date
Your doctor or surgeon deals with the bursa. The weeks after decide whether you can kneel on that knee again. See physiotherapy after surgery. Your surgeon’s protocol takes precedence.
If it is months on and you still cannot kneel, or the swelling keeps coming back, the Stalled Recovery Review is three weeks with the same physiotherapist. The first visit measures the knee and your kneeling time. The next two measure how they respond.
All of it runs on the same four stages. The Phoenix Recovery Protocol explains what each stage works on and what you have to meet to move up. No referral needed to start.
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Pain is the first thing to leave. Movement and strength are the last things trained back, and most people stop before that part is done. One Assessment and Treatment is a single 45-minute appointment at $230, nett, no GST. Your therapist finds what is actually limiting you, treats it in the same appointment, and you leave with your current stage and a written plan.
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Related reading
Sources: 1. Kivimäki J. Occupationally related ultrasonic findings in carpet and floor layers’ knees. Scand J Work Environ Health. 1992;18(6):400-402. 2. Baumbach SF, Lobo CM, Badyine I, Mutschler W, Kanz KG. Prepatellar and olecranon bursitis: literature review and development of a treatment algorithm. Arch Orthop Trauma Surg. 2014;134(3):359-370.
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