Written by Fairuuz Saleh, Principal Physiotherapist at Phoenix Rehab, AHPC A1301092H.Clinically reviewed by Louise Yow, Principal Physiotherapist & Director, AHPC A1300363H.Last reviewed 3 November 2026.
The injection helped, for a while. Three good weeks on the stairs. Then the ache came back, in the same spot a few fingers below the inside of the knee, the first time you swung your legs out of the car. So what was it, and why did it come back?
Pain on the inner shin just below the knee, worse on stairs and getting up from a chair, is often pes anserine bursitis, or the tendons above that bursa. It is common alongside knee arthritis. This page covers where it hurts and why, what an injection does and does not do, the signs that mean a doctor first, and what to do when it keeps coming back.
What is pes anserine bursitis?
Pes anserine bursitis is irritation of a small fluid sac on the inner side of the shin, about 5 to 7 cm below the knee joint, where three tendons (sartorius, gracilis and semitendinosus) attach together. The tendons themselves are often irritated too, so it is also called pes anserine tendinobursitis. It causes inner knee pain on stairs, rising from a chair and sitting cross-legged.1
Key takeaways
- Pes anserine bursitis causes pain on the inner shin about 5 to 7 cm below the knee joint, where three tendons attach together.
- It is most common in middle-aged women, and in people with knee osteoarthritis or diabetes.
- Stairs, rising from a chair and sitting cross-legged are the usual triggers.
- It is usually treated without surgery: load changes, strengthening and stretching, sometimes an injection that a doctor gives.
- Pain on the joint line itself, swelling of the whole knee or a knee that locks points to something else, such as the joint or the meniscus.
First, the signs that mean a doctor, not this page
- See a doctor the same day if the spot below the knee is hot, red and swollen, or you have a fever with it, or one calf is swollen and tender.
- See a doctor soon if the whole knee is swollen, the knee locks or gives way, the pain is there at night no matter how you lie, a lump below the knee keeps growing, or it has not eased after four to six weeks of sensible care.
None of these? Then the rest of this page is for you.
Where it hurts tells you what it usually is
| Where | What it usually points to | Who checks it |
|---|---|---|
| The inner shin, a few fingers below the knee joint, tender to press | Pes anserine bursitis or tendinopathy | A physiotherapist tests it. A doctor orders an ultrasound if needed |
| Right on the inner joint line, worse twisting or squatting deep | The joint itself: knee arthritis or a medial meniscus tear | A physiotherapist or doctor. An X-ray if arthritis is suspected |
| Along the inner side of the knee after a blow or a twist | The MCL, the ligament on the inside of the knee | A physiotherapist or doctor |
| The whole knee swollen and stiff | Something inside the joint, not the bursa | A doctor |
More on telling these apart in inside knee pain.
Had an injection?
An injection into the bursa, given by a doctor, is a common step when the pain has not settled. The review below notes that injections can ease the pain, that they carry their own risks, and that they are usually limited to a few a year.1 Whether another one is right for you is a question for your doctor.
What an injection does not do is change why the area got irritated: how much load the inner knee takes on stairs and slopes, how strong the thigh and hip muscles are that share that load, and how the knee lines up when you step down. Those are measured and trained. How we work after an injection is covered in physiotherapy after an injection.
Is it bursitis or tendinopathy?
Often both. The bursa sits under the three tendons, and the same overload irritates all of them. On an ultrasound, some people show fluid in the bursa and others show thickened tendons with no fluid at all. The treatment is similar either way: less compression and overload, then gradual strengthening.
Why does it happen with knee arthritis?
In one study, it was found in about one in five people with knee osteoarthritis.1 It is also more common in women, in people carrying extra weight, and in people with diabetes.1 When the knee is stiff or bowed, the inner side takes more load on every step, and the tendons that attach there work harder. That is why easing the arthritis load and strengthening the thigh and hip often matter more than the bursa itself.
How long does pes anserine bursitis take to go away?
It commonly settles over several weeks with load changes and exercise, and a structured strengthening and stretching program usually runs six to eight weeks.1 When it sits on top of knee arthritis, it can flare again whenever the load jumps, such as a week of hill walking or a holiday with a lot of stairs.
What should you avoid with pes anserine bursitis?
While it is irritable: sitting cross-legged or with the knees pressed together, sleeping on your side without a pillow between the knees, sudden jumps in stairs, hills or long walks, and deep squats. Stretching hard into the sore spot usually aggravates it in the early weeks. Walking on flat ground within comfort is usually fine.
Why it keeps coming back
The thinking goes: the injection fixed it, or rest will fix it. Then it comes back.
At month three you take the stairs at the void deck one at a time, and you have stopped the morning walk along the park connector because the slope back up hurts. Getting out of the car takes a hand on the door and a pause. Sitting cross-legged on the floor at a family gathering is out. The pain is in the same spot every time.
Here is the reason. The pain settled because the irritation calmed, after rest or an injection. The load that irritated it did not change: the same stairs, the same weak thigh and hip, the same knee falling inward on the step down. So the first busy week brings it back. The muscles that protect the inner knee are the last thing to come back after a flare, and they come back only when they are trained.
Has anyone pressed to find exactly which spot hurts, tested the strength of the thigh, hamstring and hip against the other side, and watched how the knee lines up on a single-leg step down? If not, nobody yet knows whether this is the bursa, the tendons, the knee joint, or all three.
What a physiotherapist does with it
Finding the real problem is half the battle. Treating it is the other half.
At the Assessment & Treatment, a physiotherapist asks when it hurts, in your words, then tests: pressing to find the exact spot, the knee joint and the MCL to rule them out, thigh, hamstring and hip strength against the other side, a single-leg sit to stand and step down, and how you walk and climb a step. If anything points to the joint, a meniscus or an infection, we tell you and write to your doctor. Scans and injections are theirs.
Most of the 45 minutes is treatment: hands-on work for the knee and the tendons, the changes that take load off the spot (how you sit, sleep and take stairs), and a strengthening program for the thigh and hip that starts where they are and is measured up at each review. You leave knowing which stage you are in, what is limiting the knee, and a written plan.
More on knee osteoarthritis if the joint is part of it, knee pain on stairs, and the MCL tear that hurts in a similar place after an injury. Every appointment is one to one with your physiotherapist for the full 45 minutes, at five clinics: Orchard, Tampines, Serangoon, Tanjong Pagar and Jurong East. Bring any scan report you have, and the date of any injection.
Questions about pes anserine bursitis
Where is pes anserine pain?
On the inner side of the shin, about 5 to 7 cm below the knee joint, where three tendons attach together. It is usually tender to press on one spot, and worse on stairs, rising from a chair and sitting cross-legged.
How long does pes anserine bursitis take to go away?
It commonly settles over several weeks with load changes and exercise. A structured strengthening and stretching program usually runs about six to eight weeks. When it comes with knee arthritis, it can flare again whenever the load on the knee jumps.
What should I avoid with pes anserine bursitis?
While it is irritable: sitting cross-legged or with the knees pressed together, sleeping on your side without a pillow between the knees, sudden increases in stairs, hills or long walks, deep squats, and stretching hard into the sore spot. Walking on flat ground within comfort is usually fine.
Is pes anserine bursitis the same as knee arthritis?
No. Pes anserine bursitis is irritation of a bursa and tendons on the inner shin below the knee, while knee arthritis affects the joint itself. They often occur together, and one study found pes anserine bursitis in about one in five people with knee osteoarthritis.
Does pes anserine bursitis need an injection?
Not usually as a first step. It is usually managed with load changes, strengthening and stretching. A doctor may offer an injection when the pain does not settle, and whether one is right for you is a question for your doctor.
Three months on, the injection has worn off and the stairs hurt again? Get Assessed & Treated, and leave knowing whether it is the bursa, the tendons or the joint, which stage you are in, and what the next stage asks of it.
Sources: 1. Pes anserine bursitis. In: StatPearls. Treasure Island (FL): StatPearls Publishing; updated January 2024. NCBI Bookshelf NBK532941.
Where are you with this right now?
1. It is settling on its own
Most injuries and most flare-ups settle over weeks with sensible load management and a return to normal movement. Improvement is judged over a month, not over a day, and good days and bad days inside that are usual. If you are doing more this month than last, and sleeping better, it is behaving the way it should. You do not need us for this, and we would rather say so.
2. It has stopped improving
You have adapted without noticing. The other side takes the load, you plan movements you used to make without thinking, and you have quietly dropped things you used to do.
What our patients say
Google reviews from our clinics in Singapore.
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. That is the gap worth measuring, and it is not measured by how you feel on the day.
The Stalled Recovery Review is three appointments over three weeks with the same therapist, because what a joint does under load cannot be read in one visit. The first finds what is limiting it. The next two measure how it responds. $690, nett, no GST, which is three appointments at $230.
3. You have had surgery, or you have a date
Recovery after an operation has a shape, and knowing which stage you are in tells you whether you are on it. Pes anserine bursitis is rarely operated on. If you have had knee surgery, such as a knee replacement, see the Knee Replacement Recovery Program, physiotherapy after surgery, or all the recovery programs, hand and physiotherapy.
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.
Next step
Find out which stage you are in
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.
Prefer to phone? Each of our five clinics has its own number on the clinics page. No referral needed to book.
Related reading
Where we are
Clinics across Singapore
ORCHARD
400 Orchard Road #12-12
Orchard Towers, S238875
NS22 Orchard MRT
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9 Tampines Grande #01-20
Asia Green, S528735
EW2DT32 Tampines MRT
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WhatsApp 8780 9608SERANGOON
265 Serangoon Central Drive #04-269
S550265 · Lift C only
NE12CC13 Serangoon MRT
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WhatsApp 8892 4121TANJONG PAGAR
10 Anson Road #02-77A
International Plaza, S079903
EW15 Tanjong Pagar MRT
Physiotherapy and hand therapy in Tanjong Pagar →
WhatsApp 8227 7074JURONG EAST
2 Venture Drive #02-02
Vision Exchange, S608526
NS1EW24 Jurong East MRT
Physiotherapy and hand therapy in Jurong East →
WhatsApp 8242 7340