Q-angle in patellofemoral pain: relationship with dynamic knee valgus, hip abductor torque, pain and function

Gabriel Peixoto Leão Almeida, Fábio Jorge Renovato França, Maurício Oliveira Magalhães, Thomaz Nogueira Burke, Amélia Pasqual Marques

To investigate the relationship between the q-angle and anterior knee pain severity, functional capacity, dynamic knee valgus and hip abductor torque in women with patellofemoral pain syndrome (PFPS). This study included 22 women with PFPS. The q-angle was assessed using goniometry: the participants were positioned in dorsal decubitus with the knee and hip extended, and the hip and foot in neutral rotation. Anterior knee pain severity was assessed using a visual analog scale, and functional capacity was assessed using the anterior knee pain scale. Dynamic valgus was evaluated using the frontal plane projection angle (FPPA) of the knee, which was recorded using a digital camera during step down, and hip abductor peak torque was recorded using a handheld dynamometer. The q-angle did not present any significant correlation with severity of knee pain (r = -0.29; p = 0.19), functional capacity (r = -0.08; p = 0.72), FPPA (r = -0.28; p = 0.19) or isometric peak torque of the abductor muscles (r = -0.21; p = 0.35). The q-angle did not present any relationship with pain intensity, functional capacity, FPPA, or hip abductor peak torque in the patients with PFPS.