moderate to severe osteoarthritis of the knee .

Inclusion Criteria:

• Subject is 50 years of age or older and has osteoarthritis of the knee.
• Subject is able to communicate meaningfully in English and comply with all study procedures.
• Subject is willing to voluntarily sign and date an informed consent form, approved by an Institutional Review Board (IRB)/Independent Ethics Committee (IEC), prior to the conduct of any study-specific procedures.
• Subject has experienced a minimum duration of pain of at least 6 months.
• For each of the last 15 days, pain level has remained at least a 3 on a Pain Intensity Numerical Rating (P-NRS) scale from 0 to 10; 0 means "no pain" and 10 means "worst pain imaginable".
• Subject is ambulatory.
• Subject has a primary diagnosis of osteoarthritis of the knee by medical history.
• Subject must be willing to abstain from any pain medicine for 12 hours prior to the study.

Exclusion Criteria:

• • Subject is pregnant and/or breast-feeding.

  • Subject has a medical condition, other than OA, that is not well-controlled with treatment; or the subject has any clinically significant condition that would, in the opinion of the investigator, preclude study participation or interfere with the assessment of pain and other symptoms of OA.
  • Subject is not able to hold a stylus or pen.
  • Subject is not able to read a computer screen.
  • Subject has any chronic pain syndrome (e.g., fibromyalgia) that, in the investigator's opinion, would interfere with the assessment of pain and/or other symptoms of OA.
  • In the judgment of the investigator, the subject has a psychiatric or psychological disorder that would interfere with the completion of the study, confound the study results or pose patient risk.