Q-Angle test. How is it measured? What does the test mean?

Last updated 15/01/2015 by The pain clinics - Interdisciplinary Health

Q-Angle measurement. How is it measured? What does it mean?

Q angle is often measured during knee examinations. Especially if the therapist wants to evaluate any malfunction in the kneecaps.

Three anatomical landmarks are needed to measure the Q angle:

Anterior Superior iliac Spine (ASIS)
ASIS is the front of the pelvis, which can be felt in front of the hip - at the level of your waist.

Patella - The kneecap
The center of the kneecap is precisely located by locating the top, bottom, and each side of the kneecap, and then drawing intersecting lines to find the middle.

Tibial tuberosity
The tibial tuberosity is the 'bone ball' about five centimeters below the patella, located on the front of the tibia.

Q Angle - Illustration: Terje Haugaa

The Q angle is measured by drawing a line (with tape measure) from the ASIS to the center of the patella. Then a new measurement is made from the middle of the patella to the tuberositas tibiae. To find the Q-angle, measure the angle between these two measurements - and then subtract 180 degrees.

A normal Q angle in men is 14 degrees and in women it is 17 degrees. An increase in the Q angle may indicate a higher risk of knee and knee problems. Including higher risk of patellar subluxation and patellar distortion.

Also read:

- Sore knee?

Source:

Conley S, «The Female Knee: Anatomic Variations»J. Am. Acad. Ortho. Surg., September 2007; 15: S31 - S36.