Trokos

Test library › Shoulder & upper arm

Surprise / anterior release test

For: Anterior instability

The ball of the shoulder slips forwards out of its socket, fully (dislocation) or partly (subluxation), usually after an earlier injury. The patient feels the shoulder is about to come out.

Best used to rule in
Sensitivity63.9%
Specificity98.9%
LR+ (positive)58.6
LR− (negative)0.37

What the numbers mean

  • Positive result: a strong rule-in: a positive result makes the diagnosis much more likely.
  • Negative result: a small shift: a negative result nudges the diagnosis down, but does not exclude it.

Source

Lo IKY, Nonweiler B, Woolfrey M, Litchfield R, Kirkley A. An evaluation of the apprehension, relocation and surprise tests for anterior shoulder instability. Am J Sports Med. 2004;32(2):301–307. 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.

Get the book for the shoulder questions that matter: neck or shoulder, a painful cuff or a torn one, and an unstable joint or the labrum

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.

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