Knee Pain
Causes, conditions, and how physical therapy helps
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The knee is the most common joint people see physical therapists about — and one of the most treatable. Most knee pain falls into a few patterns: pain around the kneecap from load and tracking issues, ligament and meniscus injuries from sport, tendon overuse, and arthritis-related stiffness.
A physical therapist can usually tell which pattern fits your symptoms in a single evaluation, without imaging. The guides below explain each condition: what it feels like, why it happens, and what treatment and recovery look like.
Guides
ACL Tears: Symptoms, Treatment & Whether You Need Surgery
An ACL tear is a rupture of the ligament that stabilizes your knee during cutting and pivoting. Surgery is common for athletes returning to pivoting sports, but research shows many people do well with structured rehabilitation alone — and even surgical cases need months of physical therapy to return safely. The decision is individual; the rehab is not optional either way.
2 min read
Inner Knee Pain: The 4 Most Common Causes
Inner knee pain usually comes from one of four things: an MCL sprain (after a blow or twist), pes anserine bursitis (tender spot below the joint line), a medial meniscus tear (joint-line pain with twisting), or knee arthritis (deep ache with stiffness after rest). Where it hurts and how it started usually narrow it down.
2 min read
IT Band Syndrome: Why Your Outer Knee Hurts When You Run
IT band syndrome is irritation where the iliotibial band crosses the outer knee, causing a sharp or burning ache that reliably appears at a certain distance into a run. It's a load and hip-strength problem — the fix is managing training volume and strengthening the hips, not stretching or foam-rolling the band into submission.
2 min read
Jumper's Knee (Patellar Tendinopathy): Symptoms & Treatment
Jumper's knee is an overload injury of the patellar tendon, felt as a pinpoint ache just below the kneecap that warms up during activity and complains afterward. Rest alone rarely fixes it — the evidence-based treatment is progressive tendon loading, which typically takes 8–16 weeks of consistent work.
2 min read
Knee Arthritis: Why Exercise Is the First-Line Treatment
Knee osteoarthritis is gradual wear of the joint's cartilage that causes stiffness, aching, and reduced activity. Every major clinical guideline names exercise therapy — not rest, not imaging, not early surgery — as the first-line treatment, because strengthening reliably reduces pain and can delay or avoid joint replacement.
2 min read
Knee Clicking and Popping: When It Matters (Usually It Doesn't)
Painless knee clicking and popping — crepitus — is common and benign: roughly a third of people with no knee pain at all have noisy knees, and noise by itself doesn't predict damage. It's worth attention only when clicks come with pain, swelling, or a catching or locking sensation.
2 min read
Knee Gives Out When Walking: What It Usually Means
A knee that buckles or gives way while walking is most often caused by quadriceps weakness — the thigh muscle briefly "switching off," especially after pain or swelling. Kneecap instability and ligament or meniscus injuries are the structural causes. Repeated buckling raises your fall risk, so it's worth an assessment.
2 min read
Knee Locking Up: True Locking vs. a Knee That Just Sticks
True locking — a knee physically stuck, unable to fully straighten until something shifts — usually means a mechanical block like a bucket-handle meniscus tear or a loose fragment, and needs prompt evaluation. Far more common is pseudo-locking: stiffness after sitting, a kneecap catch, or muscle guarding, which is not dangerous.
2 min read
Knee Pain on Stairs or Squats: What It Usually Means
Knee pain going down stairs or into a squat most often points to patellofemoral pain (runner's knee), because bent-knee positions load the kneecap joint several times body weight. Tendon pain below the kneecap and arthritis-related aching are the other common causes — the location and pattern of your pain usually tells them apart.
2 min read
Knee Pain When Kneeling: What It Usually Means
Knee pain when kneeling usually comes from the front of the knee taking direct pressure. A squishy swelling over the kneecap points to prepatellar bursitis ("housemaid's knee"); a deeper ache around the kneecap suggests patellofemoral pain; a pinpoint sore spot below it is jumper's knee; and stiff aching in older knees is often arthritis.
2 min read
Knee Pain When Running: What It Usually Means
Knee pain when running is usually one of three patterns: runner's knee (ache around the kneecap), IT band syndrome (sharp outer-knee pain that starts mid-run), or jumper's knee (a pinpoint spot below the kneecap). Almost all of them trace back to training load rising faster than the knee was ready for — which is fixable.
2 min read
Knee Stiffness After Sitting: What It Usually Means
Knee stiffness after sitting — the "movie-goer's sign" — most often points to patellofemoral pain in younger, active people or knee arthritis in people over 50. Brief stiffness that eases within minutes of moving is common and usually harmless; stiffness with swelling, worsening pain, or morning stiffness that lingers deserves a closer look.
2 min read
Knee Swelling With No Injury: What It Usually Means
A knee that swells without an injury usually means the joint is inflamed — most often from an arthritis flare, overuse irritation, or bursitis — and is producing extra fluid (an effusion). Most causes are manageable, but a hot, red, feverish knee or new calf swelling needs same-day medical care.
2 min read
MCL Sprains: Symptoms, Grades & Recovery Timeline
An MCL sprain is a stretch or tear of the ligament on the inner side of the knee, usually from a blow to the outer knee or a twist with the foot planted. Unlike the ACL, the MCL has a good blood supply and heals reliably: most tears — including most complete grade 3 tears — are managed with progressive rehab rather than surgery.
2 min read
Meniscus Tears: Symptoms, and Why Most Don't Need Surgery
A meniscus tear is damage to the C-shaped cartilage that cushions your knee. Sudden traumatic tears in young athletes sometimes need surgery, but for the far more common degenerative tears in adults over 35, high-quality trials show structured exercise therapy matches surgery's results — without the operating room.
2 min read
Pain Behind the Kneecap: What It Usually Means
Pain behind the kneecap is most often patellofemoral pain (runner's knee) — irritation of the joint where the kneecap glides on the thigh bone, flaring with stairs, squats, and long sitting. A pinpoint spot below the kneecap points to jumper's knee instead, and deep aching with stiffness in older knees suggests arthritis.
2 min read
Pes Anserine Bursitis: The Inner-Knee Pain Below the Joint
Pes anserine bursitis is irritation of a small cushioning sac (and the tendons over it) on the inner shin, two to three inches below the knee joint line. It's common in runners, people with knee arthritis, and middle-aged adults, and it almost always settles with activity changes, stretching, and strengthening — not surgery.
2 min read
Runner's Knee: Symptoms, Causes & How Physical Therapy Helps
Runner's knee (patellofemoral pain) is an irritation around the kneecap caused by how the knee is loaded — not structural damage. Physical therapy resolves most cases in 6–12 weeks with targeted strengthening and load management, without imaging, injections, or surgery.
2 min read
When to See a PT for Knee Pain (and When a Doctor First)
See a physical therapist for knee pain that has lasted more than two to three weeks, keeps returning, or is changing how you move. Go to a doctor or urgent care first for red flags: a hot swollen joint with fever, inability to bear weight after an injury, a locked knee, or rapid swelling within hours of trauma. Everything milder is reasonable to self-manage briefly — but briefly.
2 min read
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