Knee Pain When Squatting: Causes and Fixes

Knee pain is not a death sentence for squatting

I have had both knees hurt at various points in my lifting career. The first time was about eight years ago, during a phase where I was squatting heavy three times a week because some program on the internet told me to. My left knee started aching at the bottom of squats, then it started hurting walking up stairs, then it hurt sitting in my car. I was 27 and worried my knees were done.

They were not done. The problem was a combination of ramping up my squat frequency too fast, poor ankle mobility forcing my knees into bad positions, and weak VMO muscles that were not keeping my patella tracking properly. I fixed all three things over about six weeks and have squatted pain-free since then, heavier than I was squatting when the pain started.

Here is what I want you to understand: knee pain during squatting is almost always a signal that something needs to change about how you squat, how much you squat, or what supporting work you are doing. It is very rarely a signal that you need to stop squatting forever. The knee is a robust joint. It can handle enormous loads when the surrounding structures are properly prepared and the technique is sound.

That said, some knee pain does require medical attention. If you have acute swelling (your knee looks puffy compared to the other one), locking or catching (the knee gets stuck and then pops free), giving way (the knee suddenly buckles under you), or pain that is getting progressively worse despite rest and modification, go see a sports medicine doctor or orthopedic specialist. Those symptoms suggest structural damage that may need imaging.

For the majority of squatting-related knee pain, though, the causes and fixes are well understood.

The most common causes of knee pain when squatting

Most squat-related knee pain falls into one of four categories:

• •Patellofemoral pain syndrome (pain behind or around the kneecap)
• •Patellar tendinopathy (pain just below the kneecap)
• •IT band syndrome (pain on the outside of the knee)
• •Meniscus irritation (pain on the inner or outer joint line)

Each one has different causes and different fixes. Figuring out which one you are dealing with is the first step.

Patellofemoral pain: the most likely culprit

Patellofemoral pain syndrome (PFPS) is the most common cause of knee pain in the general population and in lifters. It presents as a diffuse ache behind or around the kneecap that gets worse with squatting, going up and down stairs, and sitting for long periods with your knees bent (sometimes called "movie theater sign" because it gets worse sitting in a theater seat).

What is happening: the patella (kneecap) is not tracking properly in the groove at the end of the femur. Instead of gliding smoothly up and down during knee flexion and extension, it drifts slightly to one side, creating friction and irritation on the cartilage underneath.

Why it happens in lifters:

Weak VMO (vastus medialis oblique). The VMO is the tear-drop shaped quad muscle on the inner side of the knee. Its job is to pull the kneecap medially (inward) during the last 30 degrees of knee extension. If it is weak relative to the vastus lateralis (outer quad), the patella gets pulled laterally. Most lifters have a dominant VL and a weak VMO because full-range compound movements do not preferentially target the VMO.

Tight lateral structures. A tight IT band, tight lateral quad (VL), and tight lateral retinaculum all pull the kneecap outward. Combine this with a weak VMO and you have a kneecap that tracks like a car with bad alignment.

Poor ankle mobility. When your ankles lack dorsiflexion, your knees cannot track forward over your toes properly during a squat. Instead, you compensate by letting your knees cave inward (valgus) or by shifting your weight to your toes. Both increase stress on the patellofemoral joint.

Sudden volume increases. PFPS often shows up when you rapidly increase your squat volume or frequency. The patellofemoral joint can handle a lot of load, but it needs to be conditioned gradually.

Fixes for patellofemoral pain

Terminal knee extensions (TKEs). Loop a resistance band around a squat rack at knee height. Step into the band so it sits behind your knee. Step back to create tension. With a slight forward lean, extend your knee from about 30 degrees of flexion to full lockout against the band resistance. This preferentially targets the VMO. 3 sets of 15-20 per leg, daily.

Spanish squats. Loop a heavy band around a squat rack at knee height and step into it so it sits behind both knees. Step back until the band is taut. Now squat while letting the band support your knees. This forces the quads to work through the full range while the band reduces shear force on the knee. 3 sets of 12-15. These are a game-changer for patellofemoral pain.

Peterson step-ups. Stand on a box or step with one foot. Let the other foot hang off the edge. Without shifting your weight, slowly lower the hanging foot toward the ground by bending the standing knee. Touch the heel lightly and come back up. This is done with just bodyweight and it absolutely torches the VMO. 3 sets of 10-12 per leg.

Foam roll the lateral quad and IT band. Reducing tension in the lateral structures takes pressure off the lateral side of the patella. Roll the outer quad from hip to knee, spending 60-90 seconds per side.

Patellar tendinopathy: the heavy squatter problem

Patellar tendinopathy (commonly called "jumper's knee") presents as a very specific point of pain at the bottom of the kneecap, right where the patellar tendon attaches. It hurts most at the bottom of the squat (when the tendon is under maximum load) and may feel better as you warm up, only to get worse again after training.

This is an overuse injury of the patellar tendon. The tendon is repeatedly loaded beyond its capacity to recover, leading to a failed healing response. The tendon becomes thickened, disorganized, and painful. It is more common in lifters who squat heavy and frequently, especially if they use a more knee-dominant squat style.

Cook and Purdam (2009) proposed the continuum model of tendinopathy: tendons progress from reactive (acute, reversible) to dysrepair (beginning structural changes) to degenerative (chronic structural changes). Catching it in the reactive phase is key. If you have had patellar tendon pain for less than a few weeks, it is probably reactive and will respond well to load management. If it has been going on for months, you are likely in dysrepair or degenerative territory and recovery takes longer.

Fixes for patellar tendinopathy

Isometric holds. Rio et al. (2015) showed that heavy isometric contractions of the quad (specifically, holding a leg extension at 60 degrees of knee flexion for 45 seconds) provided immediate pain relief in patellar tendinopathy. This is not just a strengthening exercise. It actually reduces pain through a neurological mechanism (cortical inhibition of the painful tendon).

Do 5 sets of 45-second holds at about 70% of your maximum voluntary contraction. You can use a leg extension machine or hold a wall sit at the specific angle. Do this before training to reduce pain during your session, and on rest days for treatment.

Eccentric decline squats. Stand on a decline board (or a weight plate under your heels) with your feet shoulder-width apart. Slowly squat down to about 60-70 degrees of knee flexion over 3-4 seconds, focusing on the eccentric (lowering) phase. Use two legs to stand back up. This progressively loads the patellar tendon in a controlled way.

Start with bodyweight, 3 sets of 15 reps, twice daily. Progress to adding a dumbbell or weight vest over several weeks.

Load management. Reduce your squat volume by 30-50% for 4-6 weeks. Do not stop squatting entirely. Tendons need load to heal, but they need the right amount. Complete rest often makes tendinopathy worse because the tendon deconditions and becomes even less tolerant of load when you return.

Avoid compression. Kneeling directly on the patellar tendon (like in lunges on a hard surface), deep squatting that jams the tendon into the knee, and using a knee strap directly over the tender spot can all increase compression and irritate the tendon. If you use knee sleeves, make sure they are not pressing directly on the painful area.

IT band related knee pain

IT band syndrome presents as pain on the outside (lateral) of the knee, usually right where the IT band crosses the lateral femoral condyle (the bony bump on the outside of your knee). It is more common in runners but lifters get it too, especially those who squat with a narrow stance or have weak hip abductors.

The IT band is not really the problem. It is a thick band of connective tissue that you cannot meaningfully stretch or "release." The real issue is usually weak glute medius and glute minimus muscles, which allow the femur to adduct (move inward) and internally rotate during squatting. This increases tension on the IT band as it crosses the knee.

Fixes

Strengthen the hip abductors. Side-lying hip abduction (3x15-20), banded clamshells (3x15-20), and banded lateral walks (3x10-12 each direction) all target the glute medius. Do these 3-4 times per week.

Widen your squat stance slightly. A wider stance reduces the demand on the IT band by changing the line of force at the knee. This is not a permanent change, just a modification while you build hip abductor strength.

Foam roll the quads and glutes, not the IT band directly. The IT band itself does not respond to foam rolling (it is too thick and stiff). But reducing tension in the muscles that attach to it (TFL, glute max, VL) can reduce the load transmitted through the IT band.

Meniscus issues

Meniscus irritation or tears present as pain directly on the joint line (inner or outer edge of the knee), possibly with clicking, catching, or a feeling of something "shifting" in the joint. Meniscus tears can be acute (a sudden twisting injury) or degenerative (gradual wear over time).

If you suspect a meniscus issue, get it checked by a doctor. An MRI can confirm the diagnosis. Many minor meniscus tears are managed conservatively with rehab and activity modification. Surgery (partial meniscectomy) is an option for tears that do not respond to conservative treatment, but the research increasingly suggests that rehab alone is as effective as surgery for most types of meniscus tears (Sihvonen et al., 2013).

For squatting with a suspected minor meniscus issue: reduce depth temporarily (squat to parallel rather than below), avoid deep flexion under heavy load, and focus on strengthening the muscles around the knee (quads, hamstrings, calves) to provide more joint stability.

Technique fixes that reduce knee pain

Regardless of which type of knee pain you have, these technique adjustments help:

Let your knees track over your toes. The old advice about "never let your knees go past your toes" is outdated and wrong. Fry et al. (2003) showed that restricting forward knee travel during squats increases hip torque and spinal loading without meaningfully reducing knee forces. Your knees are designed to go forward. Let them.

Cue "spread the floor" with your feet. This activates the external rotators of the hip and prevents the knees from caving inward. Knee valgus (inward collapse) is a significant contributor to patellofemoral pain and IT band issues.

Control your descent speed. Dropping into the bottom of a squat and bouncing out aggressively puts huge peak forces on the knee. Use a controlled 2-3 second descent, then drive out of the bottom with intent. The eccentric control matters.

Experiment with stance width and toe angle. Some people's knees feel better with a wider stance and more toe-out. Others feel better with a moderate stance. There is no universally "correct" squat stance because hip anatomy varies dramatically between individuals. If your current stance hurts your knees, try widening or narrowing it by a few inches and see what happens.

Get your ankles right. If you cannot dorsiflex enough to squat to depth without your heels rising or your knees caving in, either work on ankle mobility or use elevated heels (squat shoes or plates under your heels). Squat shoes with a raised heel are not a crutch. They are an accommodation for your individual anatomy.

Strengthening exercises for knee pain

Beyond the condition-specific exercises above, these general knee strengthening exercises help most types of squatting-related knee pain:

Reverse Nordic curls. Kneel on a pad. Slowly lean backward, keeping your body straight from knees to shoulders, controlling the descent with your quads. Go as far as you can control, then use your hands on the floor to push back up. This is one of the best quad-strengthening exercises for people with knee pain because the load is controlled and the movement is slow. 3 sets of 5-8, twice per week.

Single-leg leg press. The leg press lets you load the quads without spinal loading. Single-leg work also corrects strength imbalances between sides, which often contribute to knee pain. Start with a moderate range of motion and increase depth as pain allows. 3 sets of 10-12 per leg.

Step-ups. Forward step-ups onto a box at knee height or slightly below. Drive through the front foot to stand up, do not push off with the back foot. Lower under control. 3 sets of 10-12 per leg. These build single-leg quad strength in a functional pattern.

Nordic hamstring curls. Strong hamstrings protect the knee by sharing the load during deceleration. Kneel on a pad, have someone hold your ankles, and slowly lower your body toward the floor by extending at the knee. Fight gravity all the way down. Push yourself back up and repeat. 3 sets of 3-5 to start (these are very hard).

Programming modifications while your knees recover

You do not have to stop squatting entirely. Here is how to modify your program:

Reduce intensity temporarily. Drop to 60-70% of your max for 3-4 weeks. Pain should not exceed a 3 out of 10 during training. If it does, reduce the weight further.

Reduce volume. Cut your squat volume by 30-50%. If you normally do 5 sets of squats, do 3. If you squat 3 times per week, drop to 2.

Switch squat variations. Box squats reduce the stretch-shortening cycle at the bottom and can reduce knee stress. Front squats shift more load to the quads but often feel better on the knees than back squats because the torso stays more upright. Safety bar squats are another option that changes the loading pattern.

Add a tempo. Squat with a 3-second eccentric (lowering) and a 1-second pause at the bottom. Slower tempos reduce peak forces and give the tendons more time under a lower load. They also force you to use less weight, which is a bonus when your knees are angry.

Do your rehab exercises before squatting. TKEs, isometric holds, and band work before your squat sets can reduce pain during the squat itself and warm up the supporting muscles.

When knees should not hurt

After 6-8 weeks of the above approach (technique correction, strengthening, load management), your knees should be significantly better. If they are not, or if the pain is unchanged or worse, see a sports medicine doctor or a physical therapist who works with lifters.

Some knee pain requires professional intervention: true meniscus tears that catch and lock, ligament damage (ACL, MCL), significant cartilage defects, or referred pain from the hip or lower back. These are not things you can fix with foam rolling and TKEs.

But for the vast majority of squatting-related knee pain, the answer is straightforward: fix your technique, strengthen the muscles around the knee, manage your training load intelligently, and be patient. Knees are tough. They recover. And once they do, you will squat better and heavier than before because you will have addressed the weaknesses that caused the problem in the first place.