Abstract

Background: patellofemoral pain syndrome (PFPS) is often treated conservatively with voluntary exercise for the quadriceps femoris. Nevertheless, a substantial percentage of patients remain symptomatic. Although exercise seems a crucial element for treatment, it may serve to increase patellar irritation with the resulting dilemma that patients exercising the muscles may be simultaneously irritating the knee. Patients with patellofemoral pain syndrome have been using quadriceps strengthening exercises with varying results on muscle strength and pain. However, there are various problems associated with these forms of traditional quadriceps strengthening exercises. This study sought to explore the effects of progressive functional retraining of vastus medialis obliquus (VMO) in the context of patellofemoral pain syndrome.
Purpose: To compare the efficacy of strengthening of vastus medialis obliquus vs rectus femoris using open kinematic chain  (OKC) and closed kinematic chain (CKC)  exercises in patellofemoral pain syndrome.
Methods: This study was conducted at Yenepoya Medical College Hospital, Mangalore, India. Forty subjects with anterior knee pain fulfilling the inclusion criteria were randomly assigned to 2 groups with the mean age of 25.85 in group 1 and 27.65 in group 2. Group 1 received rectus femoris strengthening exercises. Group 2 received strengthening of vastus medialis obliqqus. Visual Analog Scale and anterior knee Pain Scale were noted before and after the interventions (i.e. either rectus femoris strengthening or  strengthening of VMO. Results: after 2weeks of intervention in Group 1 there was a significant increase anterior knee pain scale (AKPS) with mean diff of -4.95 and vastus medialis obliquus co-ordination test status. There was also a significant decrease in VAS and with mean difference of 0.5 , whereas in Group 2 has AKPS with mean difference of -23.8, VAS with the mean difference of 4.5 were all highly significant and there was a increase in VMO co-ordination test but statistically not significant.
Conclusion: Strengthening of vastus medialis obliquus clinically as well as statistically suggest that strengthening of vastus medialis obliquus is more effective than the traditional strengthening of rectus femoris in patients with patellofemoral pain syndrome.