Q-ANGLE

TEST

​• Test positioning

The client lies supine with the hips and knees extended.

​• Action

Identify the anterior superior iliac spines, the midpoint of the patella, and the tibial tubercle.

Strike a line from the anterior superior iliac spines to the midpoint of the patella, and from the tibial tubercle to the midpoint of the patella.

Place a goniometer on the knee such that the axis is over the midpoint of the patella, the proximal arm is over the line to the anterior superior iliac spines, and the distal arm is over the line to the tibial tubercle.

The resultant angle is the Q-angle.

​• Positive finding

Q-angle norms with the knee in extension are 13-degrees for males and 18-degrees for females.

Angles either greater than or less than these norms may be indicative of, but alone are not always accurate in predicting, patellofemoral pathology.

​• Special considerations & comments

Dynamic Q-angle measurements, where the client is standing and the quadriceps muscle is in a contracted state, may be more indicative of patellofemoral function and underlying lower extremity pathomechanics than static Q-angle measurements.

The accuracy of the Q-angle measurement has come into question.

The proximal attachment of the rectus femoris muscle is the anterior inferior iliac spines and not the anterior superior iliac spines.

This may provide for an invalid measurement as the anterior inferior iliac spines do not appear to fall in line between the anterior superior iliac spines and the mid-patella.