Patellofemoral Grind Test

Orthopedic Exam / Special Tests for Physical Therapy: KNEE

Clarke’s Patellofemoral Grind Test/ Clarke’s Sign/ Patellar Grind Test:

Patellofemoral Pain Syndrome, aka Runner’s Knee, occurs due to imbalances of the pulling forces imposed upon the patella during extension and flexion knee motions. As the layman’s name implies, this injury is typically associated with overuse types of trauma related to running or jumping sports. However, overuse trauma associated with PFPS is not limited to just running or jumping, but more generally may include any other compressive and repetitive activities that include walking, running, cycling, or any types of activities that may perpetuate stress on misaligned structures within the knee complex. The misalignment may occur because of a tight lateral quadriceps muscle or attached retinaculum, which can lead to an abnormal pulling of the patella, and therefore result in shearing forces which lead to cartilage breakdown within the patellofemoral joint.

Clarke’s Patellofemoral Grind Test/ Clarke’s Sign/ Patellar Grind Test:


  • To test for the presence of patellofemoral Pain Syndrome (patellofemoral joint disorder chondromalacia patellae, patellofemoral DJD); presence of Runner’s Knee

Video Demo Instructions, Procedure, Positive Test:

Special Test: Clarke’s Patellofemoral Grind Test Video Demo (Procedure below):

Special Test:Clarke’s Patellal Grind Test: PROCEDURE:

• Patient is supine with their knees extended
• Therapist compresses the patella posteriorly onto the femoral condyles and then, moderately move the patella distally
• Therapist instructs patient to contract the quadriceps muscles ( to pull patella proximally)

Special Test:Clarke’s Patellal Grind Test: POSITIVE TEST:

  • Pain, crepitus, apprehension of the patient as the irritated surfaces of the patella rub over the femur.