 The purpose of this single-center study is to evaluate the potential analgesic effects of a single oral dose of JNJ-39439335 50 mg, an investigational drug being developed for the treatment of pain, in patients with chronic osteoarthritis pain of the knee. The study will also evaluate the pain treatment response assessments and methods being used in this study. Naproxen 500 mg will be used as the active control. The hypothesis of the study is that a single 50 mg oral dose of JNJ-39439335 will be superior to placebo in relieving pain in patients with osteoarthritis knee pain following exercise. Patients will receive JNJ-39439335 , placebo an inactive substance, like a sugar pill, or naproxen 500 mg in the clinic on Days 1, 15, and 29, based on the randomly assigned like flipping a coin treatment sequence. Patients will stay in the clinic for pain assessments up to 4 hours post-dose. At 6 hours post-dose, patients will be discharged from the clinic. Patients will then take naproxen 500 mg or matching placebo at 12 hours post-dose and continue taking naproxen 500 mg or matching placebo every 12 hours for the following 6 days. During the study, starting from the first screening visit, patients will be required to discontinue all pain medication and will be encouraged not to take any rescue medication quick-relief or fast-acting medications that work immediately to relieve pain, especially during the dosing periods, for up to 6 days after each in-clinic study drug dosing on Day 1, Day 15, and Day 29, respectively. When needed, patients may take paracetamol 500 mg per dose for up to a maximum of 2 grams per day as rescue medication; however, patients are required not to take any rescue medication starting from 12 hours before through 6 hours after the in-clinic dosing on Day 1, Day 15, and Day 29, respectively. Patients pain will be evaluated for each of the 3 treatments. Safety assessments, including vital signs, physical exams, electrocardiograms and clinical lab tests will be performed at timepoints throughout the patients study participation. Patients will receive JNJ-39439335 50 mg, placebo, or naproxen 500 mg oral tablets on Days 1, 15, and 29, based on the assigned treatment sequence. At 12 hours postdose, patients in the naproxen treatment arm will start self-administering naproxen 500 mg twice daily for 6 days while patients in the placebo or the JNJ-39439335 treatment arm will take placebo twice daily for 6 days. 