Why Your Knees Hurt During Squats (And How to Fix It)

Squatting is one of the most effective movements for building lower-body strength, but it is also one of the most common sources of gym frustration. If you feel a dull ache or sharp pressure in your kneecaps when you drop into a squat, you aren't alone—and you likely don't need to stop squatting altogether.

Knee discomfort during a squat is rarely an issue with the exercise itself. Instead, it is usually a warning sign that your mechanics, ankle mobility, or hip tracking are slightly off.

Fixing these common errors can immediately alleviate stress on your joints and redirect the workload back into your muscles.

1. The Error: Knee Caving (Valgus Collapse)

When you descend or push up from the bottom of a squat, your knees should track directly in line with your toes. A common mechanical error is "knee caving," where the knees inward toward each other. This shifts the structural load away from your muscles and places intense, twisting pressure directly onto the connective tissues of the knee joint.

• The Cause: This is usually driven by underactive glute muscles (specifically the gluteus medius) that aren't firing enough to keep your thighs pushed outward.

• The Quick Fix: Before you start your set, imagine trying to "screw your feet into the floor." Push your big toe down and actively drive your knees outward so they point in the exact same direction as your shoelaces throughout the entire movement.

2. The Error: Poor Ankle Mobility

To squat deeply with an upright torso, your shins must be able to tilt forward over your feet. If your ankle joints are stiff, your heels will either lift off the ground, or your body will force you to lean excessively forward at the waist to compensate. This shifting geometry drastically increases the sheer force loaded onto your kneecaps.

• The Cause: Tight calves and stiff ankle tissues, often exacerbated by sitting at a desk all day.

• The Quick Fix: Elevate your heels slightly. Placing a small weight plate under each heel (or wearing dedicated weightlifting shoes) artificially alters the ankle angle. This allows you to squat deeply with a straight spine and takes the mechanical pressure off your knees instantly.

3. The Error: Initiating with the Knees

Many beginners start a squat by bending their knees first, pushing them straight forward over their toes before their hips move. This turns the squat into a highly quad-dominant movement that overloads the patellar tendon before the powerful muscles of your glutes and hamstrings can even assist.

• The Cause: A lack of familiarity with the "hip hinge" movement pattern.

• The Quick Fix: Sit back, not just down. Initiate the squat by unhinging your hips slightly backward, as if you are reaching for a chair positioned just behind you. Once your hips move back, then bend your knees to lower yourself down. This distributes the weight evenly across your entire lower body.

Joint-Friendly Alternatives to Keep Training

If you are working on correcting your form but still experience discomfort during standard squats, temporarily swap them out for these joint-friendly variations to keep building strength safely:

The Box Squat

Place a sturdy bench or box behind you that stops right at or slightly above parallel. Squat back until your glutes gently touch the box, pause for one second without relaxing your core, and stand back up. The box naturally forces you to sit back into your hips, taking the brunt of the weight off your knees.

The Goblet Squat

Hold a single dumbbell or kettlebell vertically against your chest, right beneath your chin. Holding the weight in front of your body acts as a natural counterweight. This makes it significantly easier to keep your torso upright, prevents your lower back from rounding, and naturally guides your hips into a cleaner, knee-friendly tracking path.