Why Does My Knee Hurt When I Squat? Causes and Solutions

Knee pain during squats is incredibly common—and incredibly frustrating. The squat is one of the most fundamental human movements, yet many people avoid it because of knee discomfort. Let's figure out what's causing your pain and how to fix it.

The Truth About Squats and Knees

First, let's clear something up: squats are not inherently bad for your knees. When performed correctly, squats actually strengthen the muscles that protect your knees. The problem isn't the squat—it's usually how you're squatting or what your body brings to the movement.

Common Causes of Knee Pain During Squats

1. Knee Valgus (Knees Caving In)

What it feels like: Pain on the inside of the knee, often accompanied by a visible collapse of the knees inward during the movement.

Why it happens: Weak glutes (especially gluteus medius), tight adductors, weak hip external rotators, or poor motor control.

The fix:

• Banded squats to cue knees out
• Glute activation before squats (clamshells, lateral band walks)
• Hip external rotation strengthening
• Verbal cue: "spread the floor" with your feet

2. Poor Ankle Mobility

What it feels like: Feeling blocked at the bottom of the squat, heels wanting to rise, pain in the front of the knee.

Why it happens: Limited ankle dorsiflexion forces compensations—often excessive forward knee travel without proper mechanics, or shift onto the toes.

The fix:

• Ankle mobility drills (knee-to-wall stretches)
• Elevate heels with small plates or squat shoes
• Foam roll calves
• Stretch soleus and gastrocnemius
• Gradually increase depth as mobility improves

3. Patellar Tendinopathy (Jumper's Knee)

What it feels like: Pain directly below the kneecap, especially at the bottom of the squat or when initiating the movement. Often worse with jumping or running.

Why it happens: Overloading the patellar tendon through high training volumes, inadequate recovery, or sudden increases in intensity.

The fix:

• Reduce squat volume temporarily
• Isometric holds at pain-free angles
• Slow eccentric (lowering) squats
• Progressive tendon loading protocol
• Address quad/hip strength imbalances
• Spanish squats for targeted tendon work

4. Patellofemoral Pain Syndrome (Runner's Knee)

What it feels like: Vague, aching pain around or behind the kneecap. Worse with stairs, prolonged sitting, or deep squats.

Why it happens: The kneecap doesn't track properly in its groove, often due to muscle imbalances, weak quads, or tight structures.

The fix:

• VMO (inner quad) strengthening
• Hip strengthening (the hip controls knee alignment)
• Patellar mobilization
• Avoid prolonged deep knee flexion initially
• Box squats to control depth
• Gradual progression back to full depth

5. IT Band Syndrome

What it feels like: Pain on the outside of the knee, especially during the descent of the squat or at specific angles.

Why it happens: Tight IT band and TFL, weak glutes, or training errors.

The fix:

• Foam rolling the TFL (not just the IT band itself)
• Hip abductor strengthening
• Glute medius activation
• Address running/training volume if applicable
• Hip stretches

6. Meniscus Issues

What it feels like: Clicking, catching, or locking in the knee, along with pain. Sometimes sharp pain at specific angles.

Why it happens: Meniscus tears can occur from trauma or degenerative changes over time.

The fix:

• Avoid painful ranges of motion
• Strengthen surrounding muscles
• Work with a healthcare provider for diagnosis
• Many meniscus issues improve with conservative treatment
• Surgery is sometimes necessary for mechanical symptoms

7. Quad Dominance / Weak Posterior Chain

What it feels like: General knee discomfort, especially with high volumes of squatting. Feeling like you're always pushing through your knees.

Why it happens: Overreliance on quads while glutes and hamstrings don't contribute their share.

The fix:

• Hip hinge patterns (deadlifts, RDLs)
• Glute-focused squat cues ("sit back")
• Hamstring strengthening
• Box squats to teach proper hip engagement

8. Going Too Deep Too Soon

What it feels like: Pain at the very bottom of the squat that improves if you cut depth.

Why it happens: Your current mobility or strength doesn't support full depth under load.

The fix:

• Temporarily limit depth to pain-free range
• Build mobility progressively
• Strengthen through available range
• Gradually add depth as capacity improves

Technique Fixes That Help Most People

1. Find Your Stance

Not everyone should squat the same way. Your hip anatomy affects your ideal:

• Stance width: Experiment between hip-width and wider
• Toe angle: Some need more turnout than others
• Bar position: High bar vs. low bar changes mechanics

2. Control the Descent

Don't dive-bomb into the hole. A controlled descent allows your muscles to stay engaged and protects your joints.

3. Drive Through the Whole Foot

Not the toes, not just the heels—the whole foot. Think "tripod foot" (big toe, little toe, heel).

4. Keep Knees Tracking Over Toes

Your knees should point the same direction as your toes, not cave in or excessively bow out.

5. Brace Your Core

A braced core protects your spine AND helps your hips and knees work properly. Take a breath, brace, then squat.

Corrective Exercises

Ankle Mobility: Knee-to-Wall Stretch

1. Face a wall, one foot a few inches back
2. Drive your knee toward the wall while keeping heel down
3. Find the maximum distance where heel stays planted
4. Hold 30 seconds, perform 10 pulses
5. Test both sides—address asymmetries

Glute Activation: Banded Clamshells

1. Lie on your side with band above knees
2. Keep feet together, open top knee
3. Don't let pelvis roll back
4. 3 sets of 15-20 per side

Quad/Tendon: Spanish Squats

1. Loop band behind knees, anchored in front
2. Lean back into the band as you squat
3. This reduces patellar tendon stress
4. Great for tendinopathy rehab
5. 3 sets of 10-15

VMO Strengthening: Terminal Knee Extensions

1. Band anchored behind knee
2. Start with slight knee bend
3. Straighten fully, squeezing quad
4. 3 sets of 20

Hip Control: Banded Squats

1. Band above knees
2. Actively push knees out against band throughout squat
3. This cues proper tracking
4. 3 sets of 10 with light weight

Modifications While You Heal

If squats currently hurt, try these variations:

• Box squats: Control depth, teaches proper pattern
• Goblet squats: Often more comfortable than barbell
• Heel-elevated squats: Helps with ankle mobility limitations
• Tempo squats: Slow descent builds control
• Partial range squats: Work within pain-free range
• Leg press: Can load legs while troubleshooting squat

When to See a Professional

Get evaluated if you have:

• Pain that doesn't improve after 2-3 weeks of modifications
• Significant swelling
• Locking, catching, or giving way
• Pain even with daily activities
• Numbness or tingling
• History of knee injury
• Sudden onset of severe pain

Building Back to Pain-Free Squats

1. Identify the likely cause using this guide
2. Address mobility limitations (ankles, hips)
3. Strengthen weak areas (glutes, VMO, hamstrings)
4. Modify technique as needed
5. Progress gradually — don't rush back to heavy weights
6. Maintain the fixes — continue accessory work even when pain resolves

The Bottom Line

Knee pain during squats is usually fixable. The squat is a natural human movement, and your body is capable of doing it well. Most issues come down to mobility restrictions, muscle imbalances, or technique errors—all of which respond to targeted work.

Be patient, be consistent, and give your body time to adapt. Pain-free squats are within reach.