What is Q Angle
The term “quadriceps angle” refers to the Q – angle also known as the patello – femoral angle.
The Q angle is an anatomical measurement used to assess the alignment of the quadriceps muscles and the patella (kneecap) with the femur (thigh bone).
To determine this you need to measure two specific lines:
- The line connecting the anterior superior iliac spine (ASIS) to the center of the Knee Cap / patella.
- The line connecting the tibial tubercle (bump on the shinbone below the knee) to the center of the patella.
The Q angle will be calculate by measuring the angle formed by these two lines.
Normally the Q angle is greater in females compared to males due to differences in hip width and pelvic structure.
Q Angle Significance
A larger Q angle will be associated with certain knee conditions like patellofemoral pain syndrome or patellar instability.
However it is important to note that the Q angle is just one factor to consider in the assessment of knee problems.
And a thorough evaluation by a healthcare professional Like orthopedician and Physiotherapist is necessary for an accurate diagnosis.
How to measure quadriceps angle
To measure the quadriceps angle also known as the Q angle or patellofemoral angle follow these steps:
- Position the patient : Have the person lie down on their back with their legs extended and relaxed.
- Locate anatomical landmarks:
- Anterior Superior Iliac Spine (ASIS): Find the bony prominence at the front of the hip on both sides.
- Patella: Identify the center of the patella / kneecap.
- Tibial Tubercle: Locate the bony bump on the shinbone, just below the kneecap.
- Mark the landmarks:
- Using a marker or a small sticker, mark the ASIS on both hips.
- Mark the center of the patella.
- Mark the tibial tubercle.
- Measure the lines:
- Using a measuring tape or ruler, measure the distance between the ASIS marker and the patella marker. This line represents the distance from the hip to the patella.
- Measure the distance between the tibial tubercle marker and the patella marker. This line represents the distance from the tibial tubercle to the patella.
- Calculate the quadriceps angle:
- Draw a line to connect the ASIS marker and the patella marker.
- Draw a line to connect the tibial tubercle marker and the patella marker.
- Measure the angle formed between these two lines using a protractor.
Key Points
Remember, this measurement provides information about the alignment of the quadriceps muscles and the patella with the femur.
If you have concerns about your quadriceps angle or knee health it is advisable to consult with a healthcare professional such as a doctor or physical therapist for an accurate evaluation.