Patellar Grind Test

The Patellar Grind Test (also called Clarke’s Sign) is a physical examination maneuver used to evaluate the integrity of the patellofemoral joint—specifically for assessing patellofemoral pain syndrome (PFPS), chondromalacia patellae, or cartilage wear beneath the kneecap. This test is most appropriate in clients complaining of anterior knee pain, “grinding,” or discomfort with kneeling/squatting.

How the Test is Performed

• Client position: Supine (lying on their back), knee extended and quadriceps relaxed.

• The examiner places one hand above the patella (superior pole) and applies gentle downward pressure on the kneecap.

• The client is then instructed to contract the quadriceps (try to push the knee downward/straighten the leg) while the examiner maintains resistance on the patella.

• A positive test: Pain, grinding, crepitus (“crunching”), or the inability to complete the maneuver due to discomfort—suggesting patellofemoral joint pathology, chondromalacia, or cartilage degeneration.

Clinical Significance

• A positive Patellar Grind Test suggests cartilage damage under the kneecap (chondromalacia), PFPS, or patellofemoral arthritis.

• The test has limited sensitivity and specificity and can cause discomfort or “false positives,” so results must be interpreted in clinical context.

• Used primarily to support a clinical suspicion of PFPS or patellofemoral chondral changes—imaging (MRI) is necessary for confirmation.

• Crepitus alone, without pain, is not always pathological; persistent pain warrants further investigation.

Assessment

• Use this test for clients complaining of anterior knee pain, crepitus with movement, or pain aggravated by squatting, stairs, kneeling, or prolonged sitting (“theater sign”).

• Document pain intensity, presence of grinding, and whether symptoms match typical complaints.

• Always compare findings to the unaffected knee if possible for reference.

Treatment

• If positive:

  • Avoid deep manual techniques, aggressive patellar mobilization, or direct compression of the kneecap.

  • Focus on gentle soft tissue techniques for the quadriceps, IT band, and peri-patellar stabilizers, as well as pain modification.

  • Integrate education on patellofemoral joint protection: avoid repetitive squatting or kneeling, and prioritize quad/hip strengthening, taping, or bracing as indicated.

  • Encourage improved movement patterns to minimize joint stress (e.g., proper squat mechanics, gradual return to activity).

Safety and Referral

• Refer for medical/orthopedic evaluation and imaging if there is persistent, severe, or functionally limiting anterior knee pain, suspected structural changes, or no progress with conservative care.

• Avoid excessive repetition of provocation tests, as this can aggravate symptoms or create unnecessary discomfort