Clinical Subgroups in Patellofemoral Pain Syndrome

(1) Muscle trunk endurance test; (2) Hip isometric strength (abductor, lateral rotation, extension); (3) Knee extensor isometric strength; (4) unilateral squat; (5) navicular drop test; (6) muscle architecture at rest of gluteus medius, gluteus maximus,vastus lateralis, vastus medialis and rectus femoris; (7) muscle activation during unilateral squat (gluteus and quadriceps muscles); (8) pennation angle of obliques vastus medialis; (9) medial patellofemoral ligament length; (10) knee pain.