Comparing Isometric, Isotonic, and Eccentric VMO Strengthening Exercises for Knee Pain and Function in Adults with Patellofemoral Pain Syndrome An 8-Week Randomized Controlled Trial

What this Trial Is About

Patellofemoral pain syndrome PFPS is a common condition causing pain at the front of the knee, especially during activities like climbing stairs, squatting, running, and sitting for long periods. This study investigates how three different types of exercises targeting the vastus medialis oblique VMO musclenamely isometric, isotonic, and eccentric contractionsaffect pain, function, and muscle structure in adults with PFPS. The trial is designed as a randomized controlled study to compare these exercise types over an 8-week period. Participants will be randomly assigned to one of three groups, each receiving a standardized physiotherapy program that includes heat therapy, transcutaneous electrical nerve stimulation TENS, and therapeutic ultrasound. After this, each group will perform their specific VMO strengthening exercises within the terminal knee extension range 0-30 degrees three times per week for 8 weeks. Exercise details vary by group isometric exercises involve 3 sets of 10 repetitions with 10-second contractions isotonic and eccentric exercises involve 3 sets of 10-15 repetitions with external resistance. During the study, assessments will be done before and after the intervention to measure pain levels using the Visual Analog Scale, functional performance with tests like WOMAC, a 30-second sit-to-stand, and stair tests, as well as ultrasound imaging to evaluate muscle architecture of the VMO and selected hip muscles. Participants will be monitored by a blinded assessor, and the study aims to identify which exercise type offers the best rehabilitation outcomes for PFPS.

Effects of Isometric, Isotonic, and Eccentric VMO Exercises in Patellofemoral Pain Syndrome