Objective
To assess the effect of knee osteoarthritis (OA) and unilateral total knee arthroplasty (TKA) on balance. Method: Fifteen patients with bilateral knee OA and fifteen patients with unilateral TKA and fifteen healthy adults were assessed by computerized dynamic posturography. The posturography test was performed 3 times at 6 different simulated conditions. We evaluated anteroposterior sway of center of gravity and strategy score of OA group, TKA group and healthy adults group. We compared the equilibrium scores of each group with normal data reported previously. We also compared strategy scores of each group.Results: Patients with bilateral knee OA and unilateral TKA showed lower equilibrium scores than normal one at the condition 4, 5, 6. But patients with unilateral TKA did not show significant equilibrium score difference as compared with bilateral knee OA patients. Patients with bilateral knee OA and unilateral TKA showed significantly lower strategy scores than normal one at the condition 4, 5, 6 (p＜0.05). But patients with unilateral TKA did not show significant strategy score difference as compared with bilateral knee OA patients. Conclusion: Patients with bilateral knee OA showed deficit of dynamic postural control due to proprioceptive dysfunction. And TKA did not affect proprioceptive change in knee osteoarthritis. (J Korean Acad Rehab Med 2007; 31: 725-729)