If your knees are fine going up stairs but hurt on the way down, you are not imagining it – and it is not random. Descending stairs places significantly more load through the patellofemoral joint (the joint between the kneecap and the femur) than ascending does. When that joint is already under stress, the extra demand of going downhill is often enough to trigger pain.
This pattern – comfortable going up, painful going down – is a classic hallmark of patellofemoral pain syndrome (PFPS), one of the most common knee complaints in active people of all ages.
Why Going Down Is Harder Than Going Up
When you descend stairs, your quadriceps are working eccentrically – contracting while lengthening to control and brake your bodyweight against gravity. This creates significant compressive force through the kneecap, pressing it against the underlying cartilage of the femur.
Going up, your body is in a more upright position with less knee bend under peak load. The forces are lower and distributed differently, which is why it typically hurts less.
The difference in pain between ascending and descending is one of the most reliable indicators that the patellofemoral joint is the source of the problem, rather than the meniscus or the joint line itself.
What Is Usually Driving Patellofemoral Pain?
Quadriceps Weakness, Particularly the VMO
The vastus medialis oblique (VMO) – the teardrop-shaped muscle on the inner lower thigh – plays a key role in controlling the kneecap’s tracking. When it is weak relative to the lateral quadriceps, the kneecap tracks slightly outward, creating uneven pressure on the cartilage underneath it.
Weak Glutes and Hip Stabilisers
As with many knee conditions, the glutes play a vital role in controlling knee alignment during loaded single-leg activities. Weak glute medius causes the knee to drop inward (valgus) during stair descent, increasing compressive load on the patellofemoral joint significantly.
Tight Quadriceps and Hip Flexors
Tight quads increase the resting tension on the patella tendon, loading the joint even at rest. Combined with hip flexor tightness from prolonged sitting, this is extremely common in desk workers who also run or train.
Poor Single-Leg Control
Stair descent is essentially a single-leg eccentric squat. If your balance, coordination, and neuromuscular control are inadequate, more stress is placed on the passive structures of the knee rather than being absorbed by the muscular system.
Other Possible Causes
While PFPS is the most likely explanation, knee pain going down stairs can also be caused by early knee osteoarthritis (particularly in over-40s), chondromalacia patella, plica syndrome, or referred pain from the hip. A proper assessment will differentiate between these and guide the right approach.
What the Rehabilitation Programme Looks Like
Many of the best knee strengthening exercises are directly applicable here. A biokineticist-directed programme typically follows a structured progression.
Step 1: Reduce Load on the Joint
Temporarily avoid descending steep stairs, running, and squats to full depth. This reduces the irritation while rehabilitation begins.
Step 2: Activate and Strengthen the VMO and Glutes
Terminal knee extensions (TKEs), shallow step-downs, clamshells, glute bridges, and wall sits are commonly used in the early stages to rebuild the muscular support around the joint.
Step 3: Build Eccentric Control
Progressive step-downs, single-leg squats with technique coaching, and Spanish squats build the strength and control specifically needed for descending stairs and loaded movement.
Step 4: Gradually Reload Stairs and Sport
As strength and control improve, you are progressively reintroduced to stairs, running, and sport-specific movements. The emphasis throughout is on controlling the knee position – preventing the inward collapse that loads the patellofemoral joint unevenly.
When to See a Biokineticist
If your knee has been painful going down stairs for more than 2–3 weeks, or if you are already modifying your daily activities to avoid it, it is time to get an assessment. Patellofemoral pain rarely resolves completely with rest alone.
Related reading: Patellofemoral Pain Syndrome: A Biokinetics Approach to Runner’s Knee | Can Weak Glutes Cause Knee Pain?
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Related reading: Patellofemoral Pain Syndrome | Best Exercises to Strengthen Your Knees | Why Your Knee Pain Keeps Coming Back