Wrist & Hand Instability Evidence: uncertain

CMC Grind Test Special Test

Orthopedic Physical Examination & Clinical Assessment Guide

CMC Grind Test Orthopedic Special Test

What is it used for?

  • Diagnosing Osteoarthritis of the Thumb Carpometacarpal (CMC) Joint.

How to Perform

  • Position: Examiner grips the patient's thumb metacarpal bone.
  • Action: Apply an axial compressive force while rotating the thumb (grinding motion) against the trapezium.

Interpretation of Results

  • Positive Test: Sudden sharp pain at the CMC joint, often accompanied by crepitus (grinding sound/feeling).
  • Why: This grinds the worn cartilage surfaces together, reproducing arthritis pain.

Diagnostic Accuracy

  • Sensitivity: 42%
  • Specificity: 80%

References