The investigators plan to investigate the effectiveness of acupuncture at highly sensitive points, compared with lowly/non-sensitive points or no acupuncture (waiting-list), in improving pain, joint function and quality of life, among patients with KOA. The safety of acupuncture will also be assessed during the study period.

Participants in the high sensitization group receive acupuncture treatment at the five highly sensitive points; Participants in the low/non-sensitization group receive acupuncture treatment at the five low/non-sensitive points and all other treatment settings will be the same as in the high sensitization group. Patients in the waiting-list group will receive standard acupuncture treatment after the study is completed.

Inclusion Criteria:

• Participants aged 40 years or older and diagnosed with mild or moderate knee osteoarthritis(KOA) are eligible to participate in the study

• The following criteria are used for diagnosis of KOA:

  • refractory knee pain for most days in the last month;
  • joint space narrowing, sclerosis or cystic change in subchondral bone (as demonstrated in X-ray);
  • laboratory examinations of arthritis: clear and viscous synovial fluid (≥2 times) and white blood cell count < 2000/mm3;
  • morning stiffness continues less than 30 minutes;
  • bone sound exists when joints was taking flexion and/or extension. If a patient meets criteria 1 and 2, or criteria 1, 3, 4, and 5, a diagnosis of KOA is confirmed.

Exclusion Criteria:

Patients will be excluded if they meet any of the following:

• diagnosed with conditions leading to skeletal disorders, such as tuberculosis, tumors or rheumatism of the knee joint and rheumatoid arthritis;
• present sprain or trauma in the lower limb;
• unable to walk properly due to foot deformity or pain;
• present with mental disorders;
• present with comorbidities including severe cardiovascular disease, liver or kidney impairment, immunodeficiency, diabetes mellitus, blood disorder or skin disease;
• females who are pregnant or lactating;
• using physiotherapy treatments for osteoarthritis knee pain;
• have used intra-articular injection of glucocorticoid or viscosupplementation in the past six months;
• received knee-replacement surgery;
• diagnosed with severe (stage 4, according to Kellgren and Lawrence radiographic classification) or late clinical stage of KOA;
• have a swollen knee or positive result of floating patella test; or'
• are participating or have participated in the other clinical trials.