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Quadriceps Femoris Muscle Angle

Aka: Quadriceps Femoris Muscle Angle, Q Angle of the Knee

Method
1. Position patient in slight knee flexion (15 degrees)
2. Measure angle between 2 lines
  1. Line 1: Anterior Superior Iliac to Patella center
  2. Line 2: Tibial Tubercle to Patella center
Normal Measurement
1. Men: 11 to 17 degrees
2. Women: 14 to 20 degrees (due to gynecoid Pelvis)
Causes of increased Q angle
1. Knock-Kneed (Genu Valgum)
2. Excessive Femoral Anteversion
3. Medial Tibial Torsion
4. Laterally positioned tibial tuberosity
5. Tight lateral Retinaculum
6. Weakness of vastus medialis oblique
7. High riding Patella (Patella alta)
Risks associated with increased Q angle
1. Patellar Subluxation
References
1. Agliettis (1983) Clin Ortho
2. Wheeless' Textbook of Orthopedics
  1. http://www.medmedia.com/oo1/234.htm

Q angle (C0231760)
Concepts	Finding (T033)
SnomedCT	15456004
English	Q angle (knee), Q angle of knee, Q angle of knee (physical finding), angles q, angle q, q angle, Q angle, Q angle (knee) (observable entity)
Spanish	ángulo Q (entidad observable), ángulo Q
Sources	Derived from the NIH UMLS (Unified Medical Language System)

Family Practice Notebook

Patients should address specific medical concerns with their physicians.

Although access to this page is not restricted, the information found here is intended for use by medical providers.

This page was written by Scott Moses, MD, last revised on 2/1/2012 and last published on 5/17/2012.

This is one of 5740 pages in the Family Practice Notebook