Intrinsic Plus Hand Clinical Presentation

Updated: May 31, 2023
  • Author: Bradon J Wilhelmi, MD; Chief Editor: Harris Gellman, MD  more...
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Physical Examination

The test most commonly used to test for intrinsic contracture is the intrinsic tightness (Bunnell) test. The examiner holds the metacarpophalangeal (MCP) joints in extension while passively flexing the interphalangeal (IP) joints. The IP joints are then passively flexed with the MCP joints held in flexion.

If IP joint flexion is blocked or lessened when the MCP joint is extended in comparison with when it is flexed, the result is positive and there is tightness of the intrinsic muscles. In contrast, if extensor contracture is present at the proximal IP (PIP) joint, then PIP joint flexion is greater with MCP joint extension.

In some circumstances, the intrinsic tightness test may not be reliable in diagnosing intrinsic contracture. IP joint stiffness and capsular or intra-articular adhesions can mask underlying intrinsic muscle tightness. In these situations, IP joint flexion may be decreased regardless of the position of the MCP joint.