Clarke's Sign (Patellar Grind Test): How to Check for PFPS

Clarke's Sign, commonly known as the Patellar Grind Test, is an orthopedic maneuver used to detect patellofemoral dysfunction, such as chondromalacia patellae or Patellofemoral Pain Syndrome (PFPS).

[Image of Clarke's Sign test knee]

1. Purpose

The primary purpose of Clarke's Sign (also known as the Patellar Grind Test) is to **test for** Patellofemoral Pain Syndrome (PFPS) or Chondromalacia Patellae. It assesses the integrity of the cartilage behind the kneecap.

2. How to Perform

1. The patient is positioned in supine (lying on their back) with the knee extended and relaxed.
2. The examiner places the web space of their hand on the superior border (top) of the patella.
3. The examiner applies a downward and inferior pressure, pushing the patella down towards the foot.
4. The examiner instructs the patient to gently contract their quadriceps muscle.

3. Positive & Negative Sign

Positive Sign (Test is POSITIVE):
A positive test (indicating patellofemoral issues) is:

• Reproduction of pain in the patellofemoral joint.
• The patient is unable to hold the contraction due to pain.

Negative Sign (Test is NEGATIVE):
A negative test is when the patient can contract the quadriceps without significant pain.