Q angle | definition of Q angle by Medical dictionary
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Related to Q angle: genu valgum
the angle formed by lines representing the pull of the quadriceps muscle and the axis of the patellar tendon.
the angle of incidence of the quadriceps muscle relative to the patella. The Q angle determines the tracking of the patella through the trochlea of the femur. As the angle increases, the chance of patellar compression problems increases.
Q angle Quadriceps angle Orthopedics The angle of alignment of the quadriceps; a Q angle of ≥ 20º is considered abnormal and creates a lateral stress on the patella, predisposing it to pathologic changes; contrarily, a normal Q angle does not preclude regional problems–eg, it may underestimate the lateral force on the knee where there is an imbalance between the vastus medialis and lateralis muscles
Q angle angle subtended by a line drawn to the vertical bisection of femur and a line drawn from the lateral margin of pelvis to the sagittal plane of the knee joint (Figure 1); normally 15° in men (>15° in women due to wider female pelvis); excessive pronators show an increased Q angle
Figure 1: Q angle. See text entry for description of Q angle.