Abstract: Objective To explore the characteristics of muscular power changes of knee joint and static balance in the elderly patients with knee osteoarthritis(KOA).Methods Isokinetic test and computerized static posturography were performed in 59 patients with KOA(KOA group) and 50 age-matched controlled subjects(conrtol group). The parameters were recorded.Results Peak torque, total work, average power and torque acceleration energy significantly decreased in KOA group compared with the control group at the low velocity of concentric pattern(P<0.05), while hamstring/quadriceps value increased statistically(P<0.05);The values of covered area, length of path, length/area statistically increased in KOA group compared with the control group only when eyes closed (P<0.01), and so did it in KOA group when eyes closed compared with eyes opened(P<0.05); There was significant relationship between length/area and hamstring/quadriceps value.Conclusion The ability of balance declined as knee muscular power decreased in the patients with KOA, especially the non-spontaneous decrease of extensor and flexor power of the knee joint.

Key words: knee joint, osteoarthritis, isokinetic test, posturography