Knee Pain When Walking: What Could Be Causing It and When to See Someone

What does the location of knee pain tell you?

Location is one of the most useful clues before you ever see a clinician.

• Front of the knee (around or below the kneecap): Often points to the patellofemoral joint or the patellar tendon — common in active people, especially when pain is worse on stairs or after sitting a long time.
• Inner (medial) or outer (lateral) edge: More likely involves the meniscus (the cartilage cushions inside the joint), the collateral ligaments, or on the outer side, the iliotibial (IT) band.
• Deep inside the joint or with swelling: May suggest osteoarthritis or a larger meniscus tear.
• Behind the knee: Can be a Baker's cyst (a fluid-filled pouch) or a hamstring tendon issue.
• Stiffness that improves after a few minutes of walking: A classic early-morning arthritis pattern.

None of these locations makes a diagnosis on their own — a physical examination is needed to narrow things down — but they help you describe what is happening and point a clinician in the right direction.

What are the most common causes of walking-related knee pain?

Osteoarthritis (OA) is the leading cause of knee pain in adults. A global meta-analysis of 88 population-based studies found that about 22.9% of adults aged 40 and older have knee OA 1Ref 1Cui A, Li H, Wang D, Zhong J, Chen Y, Lu H (2020).Global, regional prevalence, incidence and risk factors of knee osteoarthritis in population-based studies.22.9% pooled global prevalence of knee OA in adults aged 40 and older; women approximately 1.7 times more affected than men, and the condition becomes increasingly common with age. Cartilage gradually wears down, causing pain, stiffness, and sometimes swelling. Morning stiffness that eases within 30 minutes and pain that worsens after prolonged activity are the hallmark pattern.

Patellofemoral pain syndrome (PFPS) — sometimes called runner's knee — causes aching at the front of the knee, classically worse going up or down stairs, squatting, or sitting for extended periods (the "movie sign"). It is very common in active younger adults and adolescents. Exercise-based physical therapy, particularly hip and quadriceps strengthening, is the mainstay of management 2Ref 2Winters M, Holden S, Lura CB, Welton NJ, Caldwell DM, Vicenzino BT, Rathleff MS (2018).Effectiveness of conservative treatment for patellofemoral pain syndrome: A systematic review and meta-analysis.Exercise-based therapy, particularly hip and quadriceps strengthening, is the mainstay of management for patellofemoral pain syndrome.

Meniscus tears can occur acutely after a twisting injury in younger people, or gradually with wear in older adults. Pain along the inner or outer joint line, a catching or locking sensation, and difficulty fully bending or straightening the knee are typical features. MRI is the best imaging tool when a soft tissue diagnosis is needed and clinical examination has not resolved the picture.

IT band syndrome is the main cause of lateral knee pain in walkers, runners, and cyclists. Pain is characteristically sharp, felt on the outer knee, and tends to come on at a consistent point during activity rather than from the start 3Ref 3Hadeed A, Tapscott DC (2023).Iliotibial Band Syndrome.ITBS is the main cause of lateral knee pain in runners; incidence 1.6%–12% in runners and repetitive motion athletes; pain is sharp, on the outer knee, typically coming on at a consistent point during activity. It often worsens on hills or when descending stairs.

Bursitis is an inflammation of the small fluid-filled sacs around the knee. It causes localized tenderness and swelling, often from direct pressure or repetitive kneeling.

Ligament sprains — most commonly the medial collateral ligament (MCL) on the inner side — usually follow a twisting injury. They cause point tenderness and sometimes swelling on one side of the knee.

Inflammatory arthritis (gout, rheumatoid arthritis): Less common as a first presentation, but important to recognize. Gout can cause acute, intensely painful swelling, redness, and warmth in the knee. Rheumatoid arthritis often affects multiple joints and is associated with morning stiffness lasting more than an hour.

How does body weight affect knee pain?

The knee bears a load that is several times body weight with each step. A clinical trial of 142 overweight and obese older adults with knee OA found that each pound of weight lost produced roughly a fourfold reduction in the load exerted on the knee per step 4Ref 4Messier SP, Gutekunst DJ, Davis C, DeVita P (2005).Weight loss reduces knee-joint loads in overweight and obese older adults with knee osteoarthritis.Each pound of weight lost produces a fourfold reduction in the load exerted on the knee per step during daily activities. Over thousands of steps a day, that accumulates quickly.

The IDEA randomized clinical trial (454 adults, 18 months) found that combining intensive diet and exercise improved pain and function more than either intervention alone in people with knee OA 5Ref 5Messier SP, Mihalko SL, Legault C, et al. (2013).Effects of intensive diet and exercise on knee joint loads, inflammation, and clinical outcomes among overweight and obese adults with knee osteoarthritis: the IDEA randomized clinical trial.Combined diet and exercise improved pain and function more than either intervention alone in overweight/obese adults with knee OA over 18 months. Even modest weight reduction is clinically meaningful for anyone who carries extra weight and has knee pain.

Prior knee injuries also change the long-term picture significantly. A meta-analysis of 53 studies found that the odds of developing knee OA are approximately four to six times higher after a major knee injury — such as ACL tear or meniscus damage — compared with an uninjured knee 6Ref 6Poulsen E, Goncalves GH, Bricca A, Roos EM, Thorlund JB, Juhl CB (2019).Knee osteoarthritis risk is increased 4-6 fold after knee injury - a systematic review and meta-analysis.Odds of developing knee OA are approximately 4 times higher after ACL injury and 6 times higher after combined ACL and meniscus injury compared with an uninjured knee.

What can you do on your own in the short term?

For mild to moderate pain without significant swelling, instability, or an acute injury mechanism, the following measures are reasonable while you are assessing what is going on:

• Rest the knee from the activities that aggravate it. This does not mean complete immobility — gentle range-of-motion movement is generally helpful.
• Ice, wrapped in a cloth, applied for 15–20 minutes at a time, can reduce discomfort and mild swelling.
• Over-the-counter pain relievers (oral NSAIDs or acetaminophen) are among the best-supported options for knee OA pain 7Ref 7Brophy RH, Fillingham YA (2022).AAOS Clinical Practice Guideline Summary: Management of Osteoarthritis of the Knee (Nonarthroplasty), Third Edition.AAOS 2021 guideline recommends supervised exercise and oral NSAIDs (when not contraindicated) for knee OA; contains 29 recommendations for nonarthroplasty management; ask a pharmacist or clinician whether they are appropriate for your health history.
• Supportive footwear. Worn-out shoes alter knee mechanics. This is a simple and underappreciated factor.
• Avoid running on hard surfaces, hills, or descending stairs if IT band-type symptoms are present.
• Stop any exercise that reproduces sharp or worsening pain.

Gentle strengthening — especially of the hip and quadriceps — is strongly supported by evidence for both OA and patellofemoral pain. A 2024 Cochrane systematic review of 139 trials found that exercise improves pain, physical function, and quality of life in knee OA in the short term 8Ref 8Lawford BJ, Hall M, Hinman RS, Van der Esch M, Harmer AR, Spiers L, Kimp A, Dell'Isola A, Bennell KL (2024).Exercise for osteoarthritis of the knee.139-trial Cochrane review: exercise probably improves pain, physical function, and quality of life in knee OA in the short term (low-to-moderate certainty evidence).

When should you see a clinician?

If the pain came on gradually, is mild, and you can walk without severe difficulty, monitoring for a few days with rest and ice is reasonable. See a clinician promptly if:

• Pain has not improved after one to two weeks of conservative care
• Pain is significantly interfering with daily life or getting progressively worse
• You are uncertain what caused it
• The knee has swelled noticeably
• There is any locking, catching, or giving-way

A primary-care clinician can examine the knee, order imaging if needed, and refer you to physical therapy or orthopedics. Physical therapy evaluation is often one of the most effective first steps regardless of the underlying cause — the AAOS 2021 guideline for knee OA lists supervised exercise as a recommended treatment 7Ref 7Brophy RH, Fillingham YA (2022).AAOS Clinical Practice Guideline Summary: Management of Osteoarthritis of the Knee (Nonarthroplasty), Third Edition.AAOS 2021 guideline recommends supervised exercise and oral NSAIDs (when not contraindicated) for knee OA; contains 29 recommendations for nonarthroplasty management.

For some presentations, a clinical examination alone will suggest the diagnosis confidently; X-ray is the typical first-line imaging for bony changes (osteoarthritis, fracture); MRI is reserved for soft-tissue questions (meniscus, ligaments, cartilage) that remain unresolved after clinical assessment.

What will a clinician likely ask and check?

Questions a clinician will likely ask: - When did the pain start, and was there a specific injury or trigger? - Where exactly is the pain — front, back, inside, outside, or deep in the joint? - Is it constant, or does it come on with activity? - Does the knee ever lock, catch, give way, or feel unstable? - Is there any swelling, redness, or warmth? - What makes it better or worse — rest, stairs, hills, prolonged sitting? - Have you changed your activity level recently? - Any previous knee injuries or surgeries?

What to bring: - A description of exactly where the pain is and what it feels like - When it started and whether it followed an injury - What activities provoke it and what helps - Whether there has been swelling and when it appears - Any previous imaging of this knee (X-rays or MRI)

Possible tests: - Physical examination (range of motion, joint-line tenderness, stability tests, provocation maneuvers) - X-ray — good first-line imaging for osteoarthritis and bony changes - MRI — best for meniscus, ligaments, and cartilage when X-ray is not sufficient - Blood tests (uric acid, inflammatory markers) if inflammatory arthritis is suspected - Joint aspiration — if significant unexplained fluid is present, testing the fluid can confirm or rule out infection, gout, or other inflammatory causes