Why Going Downstairs Hurts Your Knee (and What to Do About It): A Boston PT’s Guide
If your knee feels fine on flat ground but flares up the moment you go downstairs or down a hill (hello, Newton’s heartbreak hill, brookline’s slopes, and the MBTA station stairs), you’re not alone.
This is one of the most common patterns I see in active adults around Boston. The good news is: it’s usually not random. There are a few predictable reasons it happens, plus a handful of simple tests and training priorities that can start shifting things in the right direction.
The simple reason stairs down are harder than stairs up:
Going downstairs and downhill increases pressure at the kneecap
When you step down, your body needs to control your descent. That control comes mostly from your quadriceps (front thigh). Your quads pull on the kneecap (patella), and the kneecap glides in a channel called the trochlear groove (knee groove). If your kneecap tracking is a little off or the tissues are already irritated, that extra demand can aggravate the area. That’s why people often say:
“Going down hurts.”
“Going up is annoying but doable.”
“Downhill walking is worse than uphill.”
Why going upstairs/uphill sometimes feels easier:
Going upstairs or uphill shifts more work toward the posterior chain (calves, glutes, hamstrings), and typically reduces the compressive stress at the front of the knee compared to controlling a step down. That is also why many people can climb stairs but hate coming back down.
Diagnostic assessment: the step-down test
One of the best quick “screening” moves for this pattern is a step-down (slowly lowering one foot to the floor from a step). When this test looks awry, it usually points to one (or more) of the following three:
1) Knee caves inward (“knee valgus”)
This matters because a knee that doesn’t stay stacked over the foot can increase irritation around the kneecap and surrounding structures. If the knee collapses inward during the step-down, it often demonstrates:
Hip weakness/control issue (especially hip abductors)
Ankle mobility restriction
Foot collapse / poor arch control
2) You feel only quads, and zero glutes
A lot of people feel their quads light up going down stairs (normal), but if you never feel the glutes helping, that is often a sign of a decreased glute recruitment. A good target during a controlled step-down:
Knee stays over the middle toe
You feel the glute on the stance leg working to stabilize you
3) Ankle mobility: the “3–4 inch” checkpoint
If you do not have that, your body will steal motion from somewhere else, and the knee often pays the price. Ankle mobility is an often overlooked limiter for knee pain, especially on stairs. A practical benchmark includes:
At least 3 inches of knee-over-toe range (and ideally 4 inches or more)
The knee should track over the middle toe
And the knee shouldn’t cave inward over the big toe to find more range
The most common diagnosis: patellofemoral pain
A very common “downstairs pain” pattern is patellofemoral pain, which is discomfort around or behind the kneecap often tied to tracking + load tolerance (more on load tolerance later). What usually helps most is not “random quad stretches”, but rather building strength and control in the chain that supports the knee:
Glute strengthening
Hamstring strengthening
Better single-leg control (especially knee-over-middle-toe mechanics)
Calf strengthening
Do not skip calves: important knee stabilizers
Calves are often forgotten in knee rehab, but they matter because they cross the knee joint (one of the calf muscles does), and thus stabilize the knee. Additionally, they help control the shin and ankle position and support shock absorption and deceleration (exactly what you need for stairs down). If someone tells me their program has no calf work, I often consider that a missing piece that needs to be addressed.
If it’s tendon-related: isometrics can be a great early tool
If your pain feels like a tendon irritation (tendinopathy / tendonitis), isometrics are often a great starting point. Isometrics = strong muscle contraction without lots of movement. They can help early by:
Loading the tissue without excessive joint motion
Reducing pain sensitivity in the short term
Acting as a clean bridge toward heavier strength training
Later, you progress into slow eccentrics (strong muscle contraction during a lengthening phase), full range strengthening, and ultimately more demand-specific work like full step-downs, split squats, and lunges.
Key framework: capacity vs. demand
Demand = stairs, hills, longer walks, workouts, busy work weeks, poor recovery, stress.
Capacity = strength, tissue tolerance, mobility, stability, sleep quality, nutrition, recovery.
Pain often shows up when demand > capacity. If you haven’t been strength training consistently, your capacity for “downhill life” may simply be lower, and Boston has a lot of downhill life. Even if nothing is torn, an irritated system is still a system giving you a message: to do more than you are currently prepared for. The fix is usually to reduce demand temporarily and build capacity progressively.
My pain rule for exercises: the 3 out of 10 guide
When rehabbing, I use a simple rule with clients:
0–3/10 pain during exercise: usually okay
4–5/10 or more: scale it back (range, depth, load, volume, or variation)
After exercise:
Pain should settle down after you’re done
If pain lingers or increases for 12–24 hours, that’s a sign the dose was too high
You don’t need “no pain ever.” You need the right dose (which can change as the rehab plan progresses), repeated consistently over time.
When should you talk to a professional?
You should get assessed if:
Pain is worsening week to week
You’re getting swelling, locking/catching, instability, or buckling
Pain is lingering after exercise for more than a day
Stairs are changing your daily life or activity choices
You’ve tried “rest” and it keeps coming back the second you resume activity
A good plan should include:
A quick movement screen (step-down, single-leg control, ankle mobility)
Strength programming that targets glutes/hamstrings/calves
A progression from low-irritation work → stair/hill tolerance
Clear guidance on dosing and flare-up management
Want help with your “stairs down” knee pain?
If you’re in Boston and want a clear answer for what’s driving your knee pain, and a plan that makes stairs feel normal again, I can help.
Book a 15-minute consult:
https://calendly.com/trevor-sculpthealth/30min?month=2026-01
