Inclusion Criteria:  Patients with primary knee OA diagnosed based on the American college of rheumatology (ACR) guidelines for early diagnosis of knee osteoarthritis 2016. Patients who had knee pain for at least 6 months and had VAS score greater than 4 out of 10 points Patients with knee OA who have Kellgren And Lawrence (KL) classification stages 2-4.  Exclusion Criteria:  Patients who have secondary knee OA caused by other pathologies Patients who have a history of corticosteroid or hyaluronate injecting into the knee joint within the past 6 months Patients who were treated by physical therapy equipment within 1 month before the study History of stroke, bleeding disorders, cancer, deep vein thrombosis, cognitive impairment, or mental disorders Contraindicate to laser therapy