Knees often hurt during squats because of a mix of technique issues, overloaded tissues around the kneecap, or existing knee conditions like patellofemoral pain or tendonitis. The pain is usually a sign that something about your form, strength balance, or joint health needs attention rather than that squats are “bad” by themselves.

Common reasons your knees hurt

  • Squatting form problems
    • Knees caving inward (valgus), drifting far over the toes, heels lifting, or leaning far forward all increase stress on the front of the knee.
* Letting the knees collapse inward especially loads the kneecap and surrounding structures, which can trigger sharp or achy pain when you go down or stand back up.
  • Patellofemoral “runner’s knee” type pain
    • Pain around or behind the kneecap when you squat, plus clicking or grinding, often points to patellofemoral pain syndrome (runner’s knee).
* It’s linked to kneecap tracking and load: deep squats, stairs, or sitting long with bent knees usually make it worse.
  • Patellar tendonitis (“jumper’s knee”)
    • If the pain is just below the kneecap at the front of the shin, especially with jumping or heavy squats, the patellar tendon may be irritated.
* This often comes from repetitive heavy loading, rapid training increases, or always training through soreness without enough recovery.
  • Weak or tight muscles around the knee
    • Weak glutes and hip muscles let your knees cave in, shifting load away from the hips and into the knee joint.
* Tight or imbalanced quads can pull unevenly on the kneecap, causing front‑of‑knee pain and a “grinding” or “locking” sensation when you squat.
  • Hip/ankle mobility limits
    • Stiff ankles or hips force your body to “borrow” motion from the knees, which can overload them even if the squat looks okay from the outside.
* People with poor ankle dorsiflexion often tip forward, lift their heels, or let knees shoot forward, all of which change how force hits the knee.
  • Underlying joint issues (arthritis, bursitis, etc.)
    • Osteoarthritis can make squatting painful because bent‑knee positions compress worn cartilage and increase friction between joint surfaces.
* Bursitis or other inflammatory conditions can cause very local, sharp pain on the inner, front, or back of the knee when you bend.

How to adjust your squat right now

  • Tweak stance and depth
    • Try a slightly wider stance, toes turned out a bit, and keep weight spread over mid‑foot and heel rather than on your toes.
* Reduce depth to a pain‑free or low‑pain range and build strength there before going deeper again.
  • Improve knee and hip position
    • Think “sit back and down” with a light hip hinge, letting hips share the load with knees.
* Actively push knees out in line with your toes to avoid caving in; using a light band above the knees can help you feel this.
  • Warm‑up and support the joint
    • Do a short warm‑up: light cycling, bodyweight squats, and leg swings before heavy sets so tissues are ready for load.
* If pain is mild and recent, ice after training and temporary load reduction (lighter weight, fewer sets) can calm irritation.

Helpful exercises (outside your main squats)

  • Strengthen glutes and hips
    • Glute bridges, single‑leg bridges, and side planks with leg lifts help your hips control knee position during squats.
* Hip abduction work (side steps with a band, clamshells) makes it easier to keep knees from collapsing inward.
  • Build quad and tendon capacity
    • Split squats, step‑ups, and leg extensions with controlled tempo strengthen the quads and patellar tendon in a more targeted way.
* Slow, pain‑tolerable squats through a partial range (tempo squats, Spanish squats) are often used in patellar tendon rehab.
  • Work on mobility
    • Ankle mobility drills (knee‑over‑toe lunges against a wall, calf stretches) reduce the need for your knees to compensate.
* Hip mobility (90/90 stretches, hip flexor stretches) can make the bottom of the squat feel more stable and less compressed at the knee.

When to worry and see a pro

  • Red flags to get checked soon
    • Sudden sharp pain, a pop, swelling, or a feeling that the knee is “giving way” after squats.
* Locking, large visible swelling, or pain that does not improve at all after several days of rest and lighter activity.
  • Why an in‑person exam matters
    • A doctor or physical therapist can test ligaments, meniscus, and patellofemoral tracking and watch your squat from different angles.
* That matters because treatment differs: tendonitis, runner’s knee, arthritis, and meniscus problems each have different best‑practice rehab plans.

Quick forum‑style take

“If your knees hurt when you squat, don’t just quit squats—change how you’re squatting, how much you’re doing, and what supporting work you do around them.”

  • Dial back weight and volume for a few weeks while you fix form and add strength/mobility work.
  • If pain is more than mild, keeps getting worse, or interferes with daily life (stairs, sitting, walking), get evaluated in person before pushing heavy squats again.

Bottom note: Information gathered from public forums or data available on the internet and portrayed here.