Page 51 - PP8inst

Measuring the Q-Angle 47

Q-Angle Measurement

The Quadriceps Angle (Q-Angle) is formed
by a line drawn from the ASIS to the center of the
kneecap, and a line drawn from the center of the
knee cap to the Tibial tuberosity. The angle formed
by the intersection of these two lines should be less
than 20 degrees in men and 25 degrees in women.
The higher value for women is due to a wider pelvic
stance.

The Q-Angle best represents the proper align-
ment of the upper and lower leg. An abnormally high
Q-Angle can cause stress on the entire kinetic chain
of the lower extremity causing many conditions from
low back pain to foot pain. The following are some
problems that may cause an increased Q-Angle:

• Wide Hips (female runners)
• Knock Knees (•genu valgum)
• Pronation of the feet
• Subluxating Patella
• High riding patella (• patella alta)
• Weak Vastus Medialis

Of particular importance is the role excessive
pronation of the foot plays in an increased Q-Angle,
and how tracking of this angle can show the neces-
sity and show the results of a custom foot orthotic.

When the foot excessively pronates, the lower
leg rotates inward, this rotation brings the kneecap
along with it. This is what increases the Q-Angle.
Recent studies have show an immediate decrease
in the Q-Angle after insertion of a custom, full-length
foot orthotic. (Immediate changes in the quadriceps
femoris angle after insertion of an orthotic device.
D. Robert Kuhn, DC, Terry R. Yochum, DC, Anton R. Cherry,
Sean S.Rodgers http://www.mosby.com/scripts/om.dll/
serve?article=a127171)