Isokinetic Training With Blood Flow Restriction for Patellofemoral Pain Syndrome

This randomized controlled trial aims to investigate the effects of isokinetic training combined with blood flow restriction (BFR) in individuals with patellofemoral pain syndrome (PFPS).

Inclusion Criteria: * Participants aged 18 to 40 years. * Clinical diagnosis of patellofemoral pain syndrome (PFPS). * Presence of anterior or retropatellar knee pain for at least 3 months. * Pain provoked by at least two activities that increase patellofemoral joint load, including squatting, stair climbing, running, jumping, prolonged sitting, or kneeling. * Average knee pain intensity of ≥3 on a 10-point visual analog scale (VAS) during aggravating activities. * Ability to participate in exercise training and attend scheduled intervention sessions. * Willingness to provide written informed consent. Exclusion Criteria: * History of knee surgery or significant trauma to the lower extremity within the previous 12 months. * Clinical evidence of other knee disorders, including ligament injury, meniscal injury, patellar instability, osteoarthritis, or tendinopathy. * Presence of neurological, cardiovascular, or systemic musculoskeletal disorders that may affect lower limb function or exercise participation. * Current participation in other structured lower extremity rehabilitation or strength training programs. * Contraindications to blood flow restriction training, including uncontrolled hypertension, vascular disease, thromboembolic disorders, or clotting abnormalities. * Use of pain-relieving injections or surgical interventions for knee pain within the previous 6 months. * Pregnancy. * Inability to complete the assessment or intervention procedures.