Muscle strength analysis of hip and knee stabilizers in individuals with Patellofemoral Pain Syndrome

Abstract

The Patellofemoral Pain Syndrome is one of the most common disorders of the knee, characterized by pain in the frontal part of the knee, which is worsened by activities that increase compressive forces on the joint. Alterations in the muscle strength of the quadriceps and hip stabilizer muscles can change patellar biomechanics, increasing joint stress and exacerbating pain symptoms. The aim of the study was to compare the strength of the hip and knee stabilizing muscles of women without and with Patellofemoral Pain Syndrome. The study included 45 women, 20 volunteers without the syndrome and 25 with Patellofemoral Pain Syndrome. Using an isometric dynamometer, the strength of the knee flexors and extensors, hip abductors and adductors, hip external rotators, medial rotators, hip flexors and hip extensors was evaluated. Women with Patellofemoral Pain Syndrome had 22% less strength of the internal rotators and 23% less strength of the knee extensors compared to healthy ones. As for the other muscle groups assessed, no differences were found. Therefore, the present study emphasizes that the quadriceps muscles are still the most affected muscle in individuals with the Patellofemoral Pain Syndrome.