60 patients with bilateral knee osteoarthritis were randomized to receive intraarticular Hylan G-F 20 injection (HA group) or saline injection (placebo group), to determine the effect of hyaluronan injections in knee osteoarthritis on the primary outcome of proprioception, as well as secondary outcomes of muscle force, pain and function. Proprioception was evaluated through the average absolute angular error (AAAE) during the passive-active reproduction method for knee flexion angles of 20, 40, and 60 degrees. While no significant between group differences were noted in the decrease in AAAE from baseline after the 1st and 2nd injections, the HA group demonstrated significant greater decreases in AAAE compared to the placebo group following the 3rd injection, and at one week follow-up after the 3rd injection.