IRCT2014090719073N1 IRCT 2016-03-18 Vice chancellor for research, Iran University of Medical Sciences comparison of two methods of exercise therapy in patellofemoral pain syndrome The comparison of effectiveness of open and closed kinetic chain exercise in reducing knee pain and improving the normal function of the patients with patellofemoral pain syndrome 2014-09-23 anticipated 64 Complete https://irct.ir/trial/17148 interventional Randomization: Randomized, Blinding: Not blinded, Placebo: Not used, Assignment: Parallel, Purpose: Treatment. N/A Chondromalacia patella. Intervention 1: The patients in open chain exercises group will do static quadriceps contraction and the Straight leg raising exercises for two months.In the first week, they will do the exercises two times a day with ten repetitions, the hold time of static contraction will be ten seconds.The exercise therapy program will be progressed to three times a day in the second week and three times a day with 15 repetitions in the third week. At the fourth week, the exercise therapy program will be progressed to three times a day and the hold time of static contraction will be 15 seconds. The progression of exercise therapy will continue in the same way until the end of the 8th week. Intervention 2: The patients in the closed chain exercises group will do semi-squat, wall slide and step ups for two months. The progression method of exercise therapy in closed chain exercises group will be as same as the open chain exercises group.