Rule of Nine Test

Published July 2, 2026 Read time 1 min read Readers 1

What is the "Rule of Nine Test" used for?

The test involves constructing nine equal size circles (or squares) on the anterior aspect of the forearm at the elbow and noting those circles where tenderness is elicited.
Equal size circles are drawn from the elbow crease and based on the width of the patient’s fully extended elbow and fully supinated forearm; the distal extent of the circles is determined so that there are three rows and three columns of circles.
The posterior interosseous nerve travels through the lateral column and the medial nerve passes through the middle column.
No nerve passes through the medial column.

If one palpates along the medial pathway of the median nerve, reproduction of pain or paresthesia within 30 seconds of compression indicates a positive test for pronator syndrome. The test is then called the pronator compression test