This study was a randomized, double-blind, placebo-controlled study evaluating the efficacy of an oral liquid HA supplement (A+HA) in symptoms relief and improvement of quality of life in knee osteoarthritis patients with mild knee pain.

Subjects were initially screened at the Randomization/Baseline Visit (Week 0). Eligible subjects were randomized at the same visit into the treatment period and received the assigned treatment in a double-blind fashion for 8 weeks. During the 8 weeks treatment period, there were three follow-up visits requested (Week 2, Week 4 and Week 8). Efficacy was measured by using Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Short Form-36 (SF-36).

Inclusion Criteria:

• Male or female age >= 40 years old
• Diagnosed with knee OA which met the definition of Ahlbӓck classification12 and had knee joint symptoms within 30 days prior to enrollment

Exclusion Criteria:

• Had administered glucosamine one month prior to enrollment
• Had known allergy to oral HA
• BMI ≧40 kg/m2
• Knee OA was caused by occupational hazard or sports injury
• Patients with known other causes of arthritis (infectious rheumatoid or psoriatic arthritis), bony or soft tissue malignancy or peripheral neuropathy involving the lower extremities, cardiopulmonary disease which limited walking more than knee pain, knee instability defined as a report of knee buckling or locking within the past month of the study knee, major neurological deficit that affected gait, psychiatric illness that limited informed consent or Parkinsonism
• Women in pregnancy
• Wheel chair users