Test library › Elbow & forearm
Biceps crease interval (BCI)
For: Distal biceps rupture
The biceps tendon tears away from its attachment on the forearm just below the elbow, usually when a bent elbow is suddenly forced straight against a heavy load.
Best used to rule inWhat the numbers mean
- Positive result: a moderate rule-in: a positive result makes the diagnosis clearly more likely.
- Negative result: a small shift: a negative result nudges the diagnosis down, but does not exclude it.
Source
Zwerus EL, van Deurzen DFP, van den Bekerom MPJ, The B, Eygendaal D. Distal Biceps Tendon Ruptures: Diagnostic Strategy Through Physical Examination. Am J Sports Med. 2022;50(14):3956–3962. Journal article (DOI) · 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.
Get the book for deciding which elbows need an X-ray after a fall, and whether the distal biceps is torn
This page gives the published figures. Rule It In, Rule It Out adds how to do this test, what counts as positive, how to read the result, and, where studied, whether combining it with other tests helps.
Coming in late 2026 as a PDF and a paperback. Join the list to hear when it's out
One study, one test, once a month
Rule It In is a free evidence letter for musculoskeletal clinicians: one recent study explained, one examination test with its real numbers. From Trokos, publisher of Rule It In, Rule It Out.