Thumb CMC grind test
For: Thumb CMC osteoarthritis
Osteoarthritis of the joint at the base of the thumb, where the thumb's long bone (metacarpal) meets a wrist bone (trapezium): cartilage loss with bone changes. Causes aching at the base of the thumb with pinching and gripping.
Rule-in strength not calculable (no false positives seen)What the numbers mean
- Positive result: no false positives were seen in the study, so no likelihood ratio can be calculated. How far to trust that depends on how many people without the condition were studied.
- Negative result: a small shift: a negative result nudges the diagnosis down, but does not exclude it.
Source
Sela Y, Seftchick J, Wang WL, Baratz ME. The diagnostic clinical value of thumb metacarpal grind, pressure-shear, flexion, and extension tests for carpometacarpal osteoarthritis. J Hand Ther. 2019;32(1):35–40. PubMed · single study
Figures as they will appear in Rule It In, Rule It Out (Trokos, forthcoming). If a newer or better study changes them, this page changes with the book. Figures last updated from the book on 2 October 2026.
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