What patellofemoral pain is
Patellofemoral pain describes pain arising from the joint between the kneecap and the groove in the thigh bone it slides through. People usually indicate it by cupping the front of the knee with a whole hand rather than pointing to one spot.
It accounts for a large share of running injuries and affects a broad population well beyond runners, with cyclists, climbers, and people who spend long periods sitting all represented.
The classic provocations are stairs, particularly going down, squatting, kneeling, hills, and the "cinema sign" of an ache building after sitting with the knee bent for a long time.
What causes it
The mechanism is excessive load through the joint surface relative to what it currently tolerates. That load is influenced by how much you do, and also by how the leg controls itself under load, particularly at the hip.
When the hip abductors and external rotators are weak or fatigue quickly, the thigh bone rotates inward under load and the knee falls toward the midline. That changes contact pressure at the kneecap without the kneecap itself doing anything wrong, which is why hip work is so effective here.
Common contributors
- A rapid increase in running volume, or a shift to hilly routes
- Weakness or poor endurance in the hip abductors and external rotators
- Quadriceps weakness, particularly through the inner range
- Reduced ankle dorsiflexion, which alters how the knee tracks in a squat
- Long periods of sitting, which loads the joint statically
- A rapid increase in squatting or lunging volume in the gym
Watch a single-leg squat or a step-down. If the knee drifts toward the midline while the pelvis drops on the opposite side, that is the pattern that reproduces the pain, and it is a control and endurance problem at the hip more often than a strength problem at the knee. Many people can produce good hip strength on a single test and lose it entirely by the tenth repetition, which is exactly what happens at mile six of a run.
What the evidence says
Exercise therapy is first-line and well supported. The strongest results come from combining hip-focused and knee-focused strengthening, which outperforms knee exercises alone in both speed of improvement and outcome at twelve months.
Hip strengthening in particular has been shown to reduce pain faster in the early weeks, which is why programmes often start there before loading the knee heavily.
Patellar taping and bracing give short-term pain relief that can be useful for getting through a session or a race, and they do not change the longer-term outcome on their own.
Running retraining, particularly increasing cadence by around 5 to 10 per cent, reduces load at the patellofemoral joint and has reasonable supporting evidence for symptomatic runners.
Imaging findings correlate poorly with symptoms here, as elsewhere. Chondromalacia and cartilage signal change appear commonly in people without knee pain, so a scan report rarely changes the plan.
Recovery timeline
Most people notice a change within four to six weeks of a consistent programme, with substantial improvement by three months. Cases that have run for a year or more take longer and need the strength work maintained rather than stopped.
It responds well to treatment and it also recurs readily if the strength work stops, so the maintenance phase matters more here than in many conditions.
| Stage | ✓ Do this | ✗ Avoid this |
|---|---|---|
| Weeks 1–2 | Reduce provocative volume: fewer hills, shorter runs, stairs one at a time. Start isometric quad holds. | Complete rest, which loses quad and hip capacity quickly |
| Weeks 2–8 | Progressive hip abductor and external rotator work, plus quads in a pain-free range. | Deep squats and lunges while they still hurt sharply |
| Weeks 6–12 | Graded return to running with a cadence increase of 5–10 per cent. Add step-downs and split squats. | Returning to hills and long runs in the same fortnight |
| Ongoing | Two strength sessions a week as maintenance, indefinitely. | Stopping the programme the week the knee feels normal |
How we treat it at Kingsway
Treating a painful kneecap
Assessment looks at how the whole leg behaves under load, not just the knee, and includes hip strength testing and a look at your running or training history.
- Single-leg squat and step-down assessment, with hip abductor and rotator strength testing
- Ankle dorsiflexion measurement, which frequently contributes
- Soft tissue release through the quadriceps, lateral thigh and hip rotators
- Patellar mobilisation and taping to reduce pain enough to start loading
- Dry needling into the quadriceps or glute medius where trigger points reproduce your pain
- A combined hip and knee strength programme, plus a running or gym progression plan
Four to six sessions over two to three months is a normal course. Because the programme is the main treatment, sessions are usually spaced two to three weeks apart with progression reviewed each time.
When to get it checked
Book an assessment if knee pain has lasted more than three weeks, is limiting stairs or running, or keeps recurring. Get seen sooner if the knee has swollen, locked, given way, or if the pain started with a specific twisting injury.
See a doctor or go to A&E if
- A knee that locks, catches or cannot be fully straightened
- Marked swelling within a few hours of an injury, which suggests bleeding in the joint
- The knee giving way under normal walking load
- Redness, heat and fever with a swollen knee
- Pain following a significant twisting injury or a direct impact
Common questions
Is my kneecap out of alignment?
Alignment explains less than it is usually credited with. Many people with textbook alignment have this pain and many with unusual alignment never do.
What responds reliably is improving how the leg controls load, particularly hip endurance, which changes joint contact pressure without changing anatomy.
Should I stop running?
Usually reducing works better than stopping. Cutting volume, flattening the route and shortening individual runs keeps the tissue loaded while giving it room to settle.
Increasing cadence by 5 to 10 per cent reduces load at the joint immediately and is worth trying in the first week.
Are squats bad for this?
Deep squats often provoke it early on, because joint contact pressure rises with knee flexion angle. Partial-range squats and split squats are usually well tolerated from the start.
Full-depth work comes back once the strength base is there, and it is a goal rather than something to avoid permanently.
How is this different from patellar tendinopathy?
Patellofemoral pain is diffuse and cupped with the whole hand around the front of the knee. Patellar tendinopathy is pinpoint tender at the bottom tip of the kneecap and you can usually put one finger on it.
They also load differently: tendinopathy is provoked most by jumping and deceleration, patellofemoral pain by stairs, hills and prolonged sitting.