Execution
- 1Support the patient’s forearm and wrist with one hand.
- 2Grasp the head of the first metacarpal with the other hand.
- 3Apply traction to the first metacarpal.
- 4Extend the thumb while applying dorsal pressure to the base of the first metacarpal.
- 5Record pain, crepitus, or reproduction of basal thumb symptoms.
Positive outcome
Crepitus and pain during traction, extension, and relocation pressure are positive. Magee describes this as an indication of arthritis. It is the same direction as the thumb joint-play traction movement but used provocatively.
Studies
| Study | Reliability | Sn | Sp | LR+ | LR− |
|---|---|---|---|---|---|
| Choa et al. (2014) | NA | 66.7 | 100 | infinity | 0.33 |
CommentChoa found traction-shift more sensitive and more specific than grind in a 30-patient, 30-control case-control study. The 100% specificity creates an infinite LR+ and should be treated as a small-sample point estimate rather than a precise multiplier. A positive test is strong support for painful CMC OA in the right context.
High Clinical Value