Abstract: The main purpose of this work was to study the alteration of muscle function and mobility after Russian current stimulation in children with knee hemarthrosis, after 8 weeks rehabilitation period. Forty volunteer hemophilic male children participated in this study. They were randomly allocated into two equal groups: control group (A): Received a designed physical therapy program (strengthening, stretching and gait training) and study group (B): Received 20 min of Russian stimulation, in addition to the program given to the control group, day after day for 8 weeks. Concentric peak torque and power of quadriceps and hamstrings at angular velocity 60° sec-1 and 120° sec-1 and functional walking were measured for each patient of the two groups before and after eight successive weeks of intervention. Mixed design MANOVA showed significant increases in isokinetic variables after the two months period compared with "before" in both groups. Moreover, mixed ANOVA was conducted to compare mean values of 6 MWT showed no significant difference between both groups. These results show the benefits of Russian current in improving muscle strength and mobility in knee hemarthrosis.