Knee Orthopaedic Test: Patellar Grind Test

The Patellar Grind Test, also known as the Clarke's Test or the Clarke's Sign, is a clinical test used to assess the integrity of the patellofemoral joint, which is the joint between the patella (kneecap) and the femur (thigh bone). It is commonly used in the evaluation of patellofemoral pain syndrome or other knee conditions that may cause pain or discomfort around the patella.

Technique involves:

• Patient should be positioned in a supine (lying on their back) position on an examination table.
• The knee being tested should be extended (straightened) with the quadriceps muscle relaxed.
• The examiner places one hand on the patient's distal thigh just above the knee to stabilize the femur (thigh bone), and the other hand on the patella.
• The examiner applies a downward pressure on the patella, while the patient is asked to contract their quadriceps muscle and attempt to straighten the knee against the examiner's resistance.
• The examiner then moves the patella in a medial (towards the midline) to lateral (away from the midline) direction, while maintaining the downward pressure.
• The examiner palpates and feels for any grinding or crepitus sensation (a crackling or grinding feeling) underneath the patella during the movement.
• The test is repeated for several repetitions, and the patient's response to the test is noted.

References:

1. Magee, D.J. (2013). Orthopedic Physical Assessment. St. Louis, MO: Elsevier Health Sciences.
2. Dutton, M. (2016). Dutton's Orthopedic Examination, Evaluation, and Intervention. New York, NY: McGraw-Hill Education.
3. Hoppenfeld, S. (2016). Physical Examination of the Spine and Extremities. New York, NY: Wolters Kluwer.
4. Kisner, C., & Colby, L.A. (2017). Therapeutic Exercise: Foundations and Techniques. Philadelphia, PA: F.A. Davis Company.
5. American Academy of Orthopaedic Surgeons (AAOS). (2018). AAOS Clinical Practice Guideline: Treatment of Osteoarthritis of the Knee: 2nd Edition.
6. Brukner, P., & Khan, K. (2017). Clinical Sports Medicine. Sydney, Australia: McGraw-Hill Education.
7. Brotzman, S.B., & Manske, R.C. (2016). Clinical Orthopaedic Rehabilitation: An Evidence-Based Approach. Philadelphia, PA: Elsevier.
8. Physical Therapy in Sport. (2017). Special Issue: Diagnosis and Management of Patellofemoral Pain: Clinical Practice Guidelines Linked to the International Classification of Functioning, Disability and Health from the Academy of Orthopaedic Physical Therapy of the American Physical Therapy Association. Physical Therapy in Sport, 25, 1-90.