Execution
- 1First rule out dominant lumbar disc behavior when clinically relevant, especially centralization with repeated movements.
- 2Perform the SIJ provocation tests: distraction, thigh thrust, compression, sacral thrust, and Gaenslen’s test.
- 3Count a test positive only when it reproduces the patient’s familiar posterior pelvic or SIJ pain.
- 4Interpret the cluster as positive when 3 or more of the 5 provocation tests are positive.
- 5Use the 2 of 4 version when Gaenslen’s test is excluded, using distraction, thigh thrust, compression, and sacral thrust.
Positive outcome
The cluster is positive when multiple provocation tests reproduce familiar SIJ region pain, commonly 3 or more of 5. Laslett’s work supports the cluster more strongly than any single SIJ provocation test. Specificity improves when symptoms do not centralize during lumbar repeated-movement assessment.
Studies
| Study | Reliability | Sn | Sp | LR+ | LR− |
|---|---|---|---|---|---|
| Laslett et al. (2005) — cluster validity study | NA | 94 | 78 | 4.27 | 0.08 |
| Laslett (2008) — evidence-based review | NA | 91 | 78 | 4.14 | 0.12 |
CommentThis is the evidence-supported way to use SIJ provocation tests clinically. The cluster is still not a replacement for controlled diagnostic block when definitive source diagnosis is required, but it is far stronger than motion palpation or isolated provocation signs. The value is high because it is a validated cluster, even though LR+ is moderate rather than extreme.
High Clinical Value