Execution
- 1Seat the patient and begins with the unaffected arm.
- 2Fully extend the elbow and draws a transverse line across the antecubital flexion crease.
- 3Lightly stroke the distal biceps contour along a central longitudinal line to identify where the distal biceps turns most sharply toward the antecubital fossa.
- 4Mark a second transverse line at the distal cusp of the biceps.
- 5Measure the distance between the two lines and compare the biceps crease interval and side-to-side ratio.
Positive outcome
A biceps crease interval greater than 6.0 cm or a biceps crease ratio greater than 1.2 is positive for distal biceps tendon rupture. Magee gives a normal BCI of approximately 4.8 cm plus or minus 0.6 cm.
Studies
| Study | Reliability | Sn | Sp | LR+ | LR− |
|---|---|---|---|---|---|
| ElMaraghy et al. (2008) | NA | 96 | NA | NA | NA |
| Devereaux & ElMaraghy (2013) | NA | 88 | 55 | 1.76 | 0.24 |
CommentMagee’s eAppendix reports weaker specificity for BCI than the original threshold paper might suggest, so the test is better as an adjunct than a stand-alone rule-in. It is most useful when swelling or pain limits palpation of the tendon. The 6 cm threshold and 1.2 ratio are the key actionable cutoffs.
Moderate Clinical Value