Runner's knee

What it is

Patellofemoral pain is pain at the joint between the kneecap and the thigh bone. The classic model blamed the kneecap tracking badly, and the modern understanding is that the femur frequently rotates underneath a reasonably well-behaved patella - driven by weakness at the hip.

That shift matters because it changed the treatment. Hip abductor and external rotator strengthening now has better evidence than knee-focused work alone, and adding hip work to a knee programme improves outcomes in trials. It is one of the clearest examples of treating a joint by strengthening the one above it.

What it feels like

• Aching around or behind the kneecap, often hard to point to precisely
• Worse going down stairs, squatting, and after running
• Sore after sitting with the knee bent for a long time - the cinema sign
• A grinding or grating sensation on bending the knee
• Often both knees, though usually one is worse

What causes it

Most people have more than one of these at once, and they feed each other. Read the list looking for the two or three that sound like your week rather than for the one true answer — the ones that describe you are the ones worth acting on.

Hip abductor and external rotator weakness

Weak glute medius and the deep hip rotators let the thigh bone drop inward and rotate on every step. The kneecap stays roughly where it is and the joint surface underneath it moves - which concentrates pressure on a smaller area.

Quadriceps weakness

The quadriceps control the knee through every bend and every landing. Weakness means the joint absorbs load the muscle should have, and vastus medialis weakness in particular affects how the patella sits.

Tight lateral structures

A tight iliotibial band and lateral retinaculum pull the patella outward in its groove, increasing pressure on the outer facet.

Training error

Rapid increases in running volume, hill work introduced suddenly, or a change of surface are the most common precipitants. The tissue tolerance is exceeded rather than the anatomy being wrong.

Foot mechanics

Excessive or poorly controlled pronation rotates the shin inward, which rotates the femur and affects the joint from below. It is a contributor rather than a cause in most people.

Stiff ankles

Restricted dorsiflexion forces the knee to travel differently in a squat or a landing and increases the load it absorbs.

Sustained knee flexion

Sitting with the knee bent for long periods loads the patellofemoral joint continuously, which is exactly why it hurts after a film or a long drive.

Anatomy

A wider pelvis, a shallow groove, or a kneecap that sits high all increase susceptibility. These are not modifiable, which is why the modifiable factors matter more.

Fear and reduced activity

Reducing activity weakens exactly the muscles that would protect the joint. Complete rest reliably makes this condition worse over weeks.

Who tends to get it

• Runners, particularly those increasing volume quickly
• Women, in whom it is more common
• Adolescents and young adults, in whom it is one of the commonest knee complaints
• Anyone with weak hip abductors, which is most people who do not train them
• People who sit for long periods with the knee bent

What makes it worse, and what settles it

The qFIT routine for this

Ready-made routineKnee Pain/Bulletproofing

qFIT already has this one built. It runs massage first, then stretching, then strength — the order that works on a body that is already sore — and every activity in it carries the reason it is there.

The button below opens your Checklist with this routine already selected, so instead of your whole list you land on just its Categories, Targets and Exercises, each with its checkbox, ready to tick as you work through them.

Have more than one problem? Tick yours under My Problems on My Profile and your Checklist's Routine list gains Recommended for my problems — every routine for the problems you picked, merged into one. Your picks stay private; that filter is the only thing they feed.

Get it checked if…

Locking, giving way or effusion suggests internal derangement

And whatever the body part: chest pain or unusual breathlessness on exertion; a fever alongside the pain; unexplained weight loss; pain that is constant and unrelated to how you move; new numbness, weakness or loss of bladder or bowel control; or one calf that is swollen, warm and painful. Any of those, stop and get assessed.

How it usually goes

Combined hip and knee strengthening improves symptoms in the majority of people over six to twelve weeks, and the hip component is what distinguishes a programme that works from one that plateaus. Relapse is common if the strength work stops when the pain does, so it should continue well past symptom resolution. Locking, giving way, significant swelling or a knee that hurts at rest is a different problem and is worth having assessed.

Prevalence basis: Patellofemoral pain consensus statements

Others the same routine covers

These share the Knee Pain/Bulletproofing routine, so the work is the same. If one of them also sounds like you, that is a reason to expect more from it, not less.

This is general information, not a diagnosis, and it cannot examine you. If it matches you, use it to ask better questions of a clinician rather than to replace one.