What is the Midcarpal Instability Test?
Midcarpal instability (MCI) refers to a range of wrist joint dysfunctions involving excessive or abnormal movement in the proximal carpal row and distal carpal rows. Common symptoms include ulnar-sided wrist pain, a sense of weakness or instability, and sometimes a distinctive “clunk” as the wrist moves into ulnar deviation. MCI often results from repetitive stress or trauma, leading to conditions like palmar midcarpal instability (PMCI), dorsal midcarpal instability, or extrinsic midcarpal instability.
The midcarpal shift test, also known as the Lichtman test, is commonly used to evaluate MCI. Named after David Lichtman, this test places a palmarly directed force on the distal carpal row as the wrist moves into radial deviation and ulnar deviation. This maneuver stresses the arcuate ligament and other supporting structures, potentially revealing instability when a clunk or abnormal shift occurs.
MCI falls under Carpal Instability Nondissociative (CIND), a broad category that also includes conditions like volar intercalated segmental instability (VISI). In VISI, the carpal bones on the palm side shift downward, creating a specific pattern of instability. Midcarpal instability can also involve weakened ligaments, such as the dorsal radiocarpal ligament, leading to inconsistent control over the carpal bones and resulting in a distinct wrist joint dysfunction.










