Thumb MCP joint lateral stability test

Test Procedure: Stabilize the thumb metacarpal with one hand, and with the other hand grasp the thumb proximal phalanx. With the MP joint in 0° extension, gently push the proximal phalanx in an ulnar direction and then a radial direction. Repeat the test with the MP joint in 30° flexion. Positive results: Passive lateral deviation greater than 35 degrees Passive lateral deviation 15 degrees more than the uninjured side Also, pain with this test and point tenderness at the collateral ligament indicates at least mild sprain Negative Results: No excessive deviation Implications of positive test result: Collateral ligament rupture (partial or complete)