the effect of mobilization on improvement of physical function

background: knee osteoarthritis is one of the most common disabilities, which may lead to some limitations in physical activity. this study aimed to evaluation of grade one mobilization in improvement of physical function. methods: in this single blind clinical trial with a randomized sampling method, 30 patients of grade two or three, knee osteoarthritis were assigned into three groups: group one mobilization + exercise therapy, group two exercise therapy and group three mobilization. ultrasound with the intensity below 0.2 w/cm 2 in three minutes was used for all groups as placebo. the duration of treatment was 10 sessions for three weeks. outcome was measured by womac questionnaire form (likert type) before and one week after treatment. results: physical function showed no significant difference between before and after treatment and between before treatment and follow up among the groups (p>0.05). the difference of physical function after treatment compared to before treatment was significant in all groups (p<0.05).  only group one showed a significant difference of physical function at the follow up period compare to before treatment (p<0.05). conclusion: this study confirmed that grade one mobilization of patellofemoral joint may improve physical function of the grade two or three knee in osteoarthritis patients. exercise therapy combined with mobilization, would prolong treatment effect up to one week.