Daily Treadmill Walking Does NOT Cause Knee Osteoarthritis
No, daily walking on a treadmill for exercise does not cause osteoarthritis of the knees—in fact, walking is strongly recommended as a core treatment for knee OA and is not associated with structural joint damage in people at risk of or with mild knee OA. 1, 2
Evidence Against the "Wear and Tear" Myth
Strong Evidence: Walking Does Not Increase OA Risk
A systematic review examining occupational activities found strong evidence that sitting, standing, and walking activities do NOT increase the risk of hip OA in men, and moderate evidence for no increased risk of knee OA in both men and women. 1
A prospective study from the Multicenter Osteoarthritis Study (MOST) followed 1,179 participants over 2 years and found no association between daily walking (average 6,981 steps/day) and radiographic worsening or cartilage loss in people at risk of or with mild knee OA. 2
Even walking at moderate to vigorous intensity (>100 steps/min) was not associated with structural knee changes. 2
A case-control study of 4,316 people found little evidence that increased levels of regular physical activity throughout life lead to increased risk of knee OA later in life. 3
Walking is Actually Strongly Recommended Treatment
Guideline Recommendations
The 2019 American College of Rheumatology/Arthritis Foundation guidelines STRONGLY recommend exercise for all patients with knee OA, with walking being the most commonly studied and evaluated form of aerobic exercise. 1
Walking (either on treadmill or as supervised community-based indoor fitness walking) is explicitly listed as an appropriate exercise option with no hierarchy suggesting one form is superior to another. 1
The American College of Rheumatology states that while OA pain typically worsens with activity, regular structured exercise programs (including walking) significantly reduce pain and improve function. 4
Clinical Benefits of Walking for Knee OA
A 12-week low-load treadmill walking program significantly improved knee pain, joint function, and ability to perform activities of daily living in patients with mild to moderate knee OA. 5
Exercise training (including walking) can prevent cartilage degeneration, inhibit inflammation, and prevent loss of subchondral bone in knee OA. 6
Walking improves pain, stiffness, joint dysfunction, and muscle weakness in patients with knee OA. 6
What Actually DOES Cause Knee OA
Occupational Risk Factors (Not Exercise)
Strong evidence shows that kneeling, squatting, and bending activities in occupational settings increase the risk of knee OA. 1
Heavy physical demands and lifting in occupational contexts (not recreational exercise) show strong evidence for increased knee OA risk. 1
The key distinction is between repetitive occupational loading versus controlled exercise—the former involves prolonged, repetitive joint stress without adequate recovery, while exercise involves structured activity with appropriate rest. 1
Previous Knee Injury is the Strongest Risk Factor
Previous knee injury is associated with a greatly increased risk of knee OA (odds ratio 8.0,95% CI 2.0-32.0), and most injuries occur through participation in physical activities. 3
When choosing activities, consider the likelihood of joint injury, as some activities carry higher injury risk than others. 3
Common Pitfalls and Misconceptions
The "Wear and Tear" Fallacy
The perception that physical activity damages joints through "wear and tear" is a major barrier to exercise engagement, but this perception is incorrect and contradicted by evidence. 7
Conflicting research findings and ambiguity have generated uncertainty, but a nuanced understanding shows that appropriate physical activity does not accelerate joint degeneration. 7
Quadriceps muscle weakness is actually a risk factor for knee OA, often as a consequence of inactivity—not activity. 1
Physical Inactivity is the Real Problem
Physical inactivity is recognized as a risk factor for many diseases and may contribute to the morbidity associated with knee OA. 1
Inactivity compounds age-related changes and increases risk for coronary artery disease, diabetes mellitus, obesity, and depression—all of which can worsen OA outcomes. 1
Practical Implementation for Daily Treadmill Walking
Exercise Prescription
Patients should be encouraged to walk regularly as part of their OA management, focusing on patient preferences and access rather than avoiding activity. 1
Exercise programs are more effective when supervised by physical therapists, often in a class setting, rather than performed alone at home. 1
There is no uniformly accepted level of pain at which a patient should or should not exercise—use shared decision-making between clinician and patient. 1
When to Modify Activity
Clinical trials of exercise for OA include patients with pain and functional limitations, and improvements have been demonstrated, so results are generalizable to most patients with OA-related pain. 1
Patients should be reassured that pain during exercise does not necessarily indicate joint damage, though acute inflammatory flares may require temporary rest. 4, 8