Sacroiliac Distraction Test

Description and Purpose

The SIJ (Sacroiliac joint) Distraction (Colloquially know as Gapping) test is used to add evidence, positive or negative, to the hypotheses of an SIJ sprain or dysfunction when used in the Laslett SIJ Cluster testing. This test stresses the anterior sacroiliac ligaments.[1][2][3][4][5] This test has also been described as the Transverse Anterior Stress Test or the Sacroiliac Joint Stress Test.


SI Distraction Test - Vertically oriented pressure is applied to the anterior superior iliac spinous processes directed posteriorly, distracting the sacroiliac joint.

1. The patient lies supine and the examiner applies a vertically orientated, posteriorly directed force to both the anterior superior iliac spines (ASIS)[1] [3][4][5]

Note: Cook and Hegedus (2013) suggest applying a sustained force for 30 seconds before applying a repeated vigorous force in an attempt to reproduced the patient’s symptoms. However, Laslett (2008) does not suggest any timings or changes in force.

Because of the lack of standardization in the technique it is quite feasible different therapists will practise this test different ways, giving rise to variability in response and lowering the inter-tester reliability.[4][6] No evidence to suggest either method is preferable[6], therefore, more evidence needed.

2. The presumed effect is a DISTRACTION of the anterior aspect of the sacroiliac joint.[4][5]

3. A test is positive if it reproduces the patient's symptoms. This indicates SIJ dysfunction or a sprain of the anterior sacroiliac ligaments[1][2][3][4][5]

However, this test should be used in concordance within a SIJ testing cluster to ensure maximum reliability and validity when confirming hypotheses[7][8][3][5][9][10] See Laslett SIJ testing cluster for further information



The Diagnostic Accuracy of the Distraction test for SIJ dysfunction is described below (Original data from Cook and Hegedus (2013).

Author Reliability Sensitivity Specificity LR+ LR- QUADAS Score (0-14) Cook and Hegedus 2013 QUADAS Score (0-14) Gunning 2013 CEBM (0-5) With qualitative J Study Conclusion
Albert et al 2000 84% 4-14 (Average = 9) 100 NA NA 7 7 Score = 4
Patient Spectrum
535 women fulfilling broad inclusion criteria with daily pain at gestation week 33.
Reference Standard
Reference standard performed on all participants
Independent blind comparisons with Gold standard
No gold standard used but 2 examinations performed by individual and blinded assessors
Test characteristics
Presented as expected but without likelihood ratios
Method and all analyses detailed clearly. All reproducible
Test has reasonable specificity and inter-rater reliability and should be used as an assessment tool in pregnant women
Blower and Griffin 1984 63% Not tested 89 NA NA 5

6 - Reference standard used but minimal description. 2 studies reported in 1. Very messy study.

Score = 2

Patient Spectrum Consecutive admissions of AS patients with varying stages of progression.

Reference Standard

Performed on all participants

Independent Blind comparisons with Gold Standard

No gold standard used/ Blind testing of index test but not reference standard

Test Characteristics Specificity produced but not sensitivty


Test has reasonable reliability and sensitivity and can be used to aid assessment of AS with LBP
Kokmeyer et al 2002 46% Not tested Not tested NA NA NA Abstract only

Score = 2 (Abstract only)
Patient Spectrum
78 subjects with varying degress of LBP
Reference Standard
Unclear from abstract
Independent blind comparisons with Gold standard
Unclear from abstract
Test characteristics
Unclear from abstract
Well described and detailed method

Test is best when used within a multitest cluster of 5 SIJ tests.
Laslett et al 2005 Not tested 60 81 3.2 0.5 12 12 - Full usage of normally available clinical data not allowed. Unclear if intermediate results reported. Score = 5
Patient Spectrum
48 subjects with broad spectrum. Accepting range of buttock pain with/without Lumbar or lower limb symptoms. Excluded if midline pain above L5
Reference Standard
Every subject received reference standard diagnosis via Fluroscopy contrast guidance of a diagnostic spinal injection.
Independent blind comparisons with Gold standard
Therapist and Radiologist blinded to opposite assessment. Gold standard diagnostic spinal injection used.
Test characteristics
Presented as expected
Concisely and clearly detailed method and results analysis
Test best used when used within a multitest cluster (Laslett et al 2005)

Laslett and Williams 1994

(Cited Cook and Hegedus 2008)

69% Not tested Not tested NA NA NA Unable to obtain paper Unable to obtain paper NA
McCombe et al 1989 36% Not tested Not tested NA NA NA Abstract only Score = 0 (Abstract only)
Patient Spectrum
83 subjects but unclear in abstract how met or inclusion criteria. Unclear as to extent and type of LBP
Reference Standard
Unclear from abstract. Study tests inter-rater reliability of multiple tests but still unclear
Independent blind comparisons with Gold standard
Unclear from abstract
Test characteristics
Unclear from abstract
Some description of methods and analysis in abstract but not reproducible.
Ozgocmen et al 2008 Not tested 23 81 1.24 0.94 10 10 – unclear if MRI interpreted with physio findings. Withdrawls not explained. No intermediate results. Score = 4
Patient Spectrum
Unclear as to how subjects were recruited from clinic and unclear as to extent of dysfunction, except present for 3 months +
Reference Standard
MRI used on all tests subjects
Independent blind comparisons with Gold standard
Physiotherapists were blinded of MRI results while assessing subject.
Test characteristics
Presented as expected
Very detailed method and analysis
Test has acceptable reliability when used in early stage sacroilitis. However, reliability, sensitivity and specificity improved when in a multi-test cluster.
Potter and Rothstein 1985 94% Not tested Not tested NA NA NA 5 – No reference measure used. Study investigate inter-rate reliability. Score = 3
Patient Spectrum
17 subjects with wide range of symptoms. Unilateral buttock pain, 1 year + with/without lumbar or lower limb pain or paraesthesia. Accepted pts who would normally be tested for SIJ dysfunction.
Reference Standard
Reference standard identical to index test but carried out on every subject by independent and blind assessor
Independent blind comparisons with Gold standard
No gold standard used but assessors independent and blind of each other.
Test characteristics
Only reliability and assessor agreement assessed
Very detailed and specific description of method and analyses
Reliability of test is poor
Robinson et al 2007 82% Not tested Not tested NA NA NA 10 – Reference standard not independent of index test + clinicians deprived of pain localisation on examination Score = 3
Patient Spectrum
61 subjects with either AS, post partum pelvic pain or no pain.
Reference Standard
Tests performed on every subject twice but 2 random, separate, independent and blind assessors in a random order.
Independent blind comparions with Gold standard
Reference standard same as index test and not gold standard. Assessors were independent and blinded.
Test characteristics
Only reliability and assessor agreement reported.
Well detailed methodology and analyses
Reliability of the test is moderate to good. However, test is better when performed in a multi-test cluster.
Russell et al 1981 Not tested 11 90 1.1 0.98 5 PUBmed indexed but no abstract available therefore, not obtained Unable to obtain Test not valid (van der Wruff cited Russell et al 1981)
Average (Mean) 65.4% 25.75 88.2 1.85 0.81 7.8 7.8 2.57 Test is acceptable used on its own, but it is best used within a cluster

Sensitivity – The possibility of a positive test resulting in someone with the pathology
Specificity – The probability of a negative test resulting in someone without the pathology
Positive Likelihood Ratio (LR+) –The ratio of a positive test result in people with the pathology to a positive test result in people without the pathology.
Negative Likelihood Ratio (LR-) – The ratio of a negative test result in people with the pathology to a negative test result in people without the pathology.
Reliability – Likelihood of results from test to be reproduced again (Expressed as percentage or as decimal)


  • Ham 1996[12] used the distraction test as a measure for pelvic fracture so it was not included from Cook 2013[1]
  • Ozgocmen 2008[9] assessed patients with acute sacroilitis
  • QUADAS score replicated from Cook 2013. Originally produced by Whitling 2003[13]. Cook and Hegedus (2013) cited Whitling 2005[14]. It is a quality tool to assess Diagnostic Accuracy Studies[13]
  1. Score of 7-14 “yesses” has typically been seen to indicate a high-quality diagnostic accuracy study while a score below 7 indicates a poor quality diagnostic accuracy study[15][16][17]
  2. However, Cook and Hegedus (2013) suggest a score of 10 “yesses” should be associated with a high-quality study and a score below 10 should be associated with poor designed studies[18][19]
  • A systematic review by van der Wurff et al (2000b)[20] found that ¾ of studies included which looked at distraction found that it was not a valid test and 2/3 in van der Wurff et al (2000a)[21] found it unreliable.
  • Stuber 2007[22] found only one study in a systematic review investigating Distraction Test.[23] Stuber 2007 reported 60% sensitivity. The search excluded any papers which didn’t compare to a gold standard. This explains why only one study in Stuber 2007 was included as most of the studies from Cook and Hegedus (2013) did not utilize a gold standard comparative.
  • New evidence has come out since then suggesting the test is sufficiently and reasonably reliable and valid when used independently but is best when used in a cluster[3][4][5][9][10][22]
  • Gold standard/Reference standard for SIJ dysfunction is a sacroiliac joint injection confirmed under fluoroscopy or CT-guidance using a local anesthetic solution.
  1. The injection is performed twice on 2 separate visits with the diagnosis being confirmed when the patient reports a significant change in relief from pain.
  2. Maigne et al 1998, Maigne et al (1996)[24] and Schwarzer et al (1995)[25] have used at least a 75 percent change in relief of pain before a response to injection is considered positive and the SIJ deemed the source of pain.
  3. However, there is some debate that injection into ligament posterior to joint rather than an intra-articular injection is actually more effective[26][27]
  • A brief search on PubMed and Medline with the search term (sacroiliac joint AND (distraction test OR gapping test OR Transverse Anterior Stress Test OR Sacroiliac Joint Stress Test OR pain provocation)) returned 27 results on PubMed showing no other studies other than the ones published in Cook and Hegedus (2013)


Although this test does have moderate to good reliability[10] and is reasonably accurate in diagnosing SIJ dysfunction/sprain[4],the evidence shows that it is best used when used within a cluster (SIJ cluster testing / Test Item Clusters for Sacroiliac Dysfunction)[7][8][3][4][5][9][10]

See Laslett Cluster Testing for further information (SIJ cluster testing)

See Also


  1. 1.0 1.1 1.2 1.3 Cook, C, Hegedus, E. (2013). Orthopedic Physical Examination Test: An Evidence Based Approach. New Jersey: Prentice Hall.
  2. 2.0 2.1 Cook, C., Cleland, J., Huijbregts, P. (2007). Creation and Critique of Studies of Diagnostic Accuracy: Use of theS methodological Quality Assessment Tool. J Manipulative Physiol Ther, 15(2), 93-102.
  3. 3.0 3.1 3.2 3.3 3.4 3.5 Laslett M, (2008). Evidence-Based Diagnosis and Treatment of the Painful Sacroiliac Joint. J Man Manip Ther. 2008; 16(3): 142–152.
  4. 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 Laslett M, Aprill C, McDonald B, Young S (2005). Diagnosis of sacroiliac joint pain: validity of individual provocation tests and composites of test. Man Ther. 2005;10:207-218.
  5. 5.0 5.1 5.2 5.3 5.4 5.5 5.6 Laslett M, Young SB, Aprill CN, McDonald B, (2003). Diagnosing painful sacroiliac joints: A validity study of a McKenzie evaluation and sacroiliac joint provocation tests. Aust J Physiother 2003;49:89–97.
  6. 6.0 6.1 Levin U, Nilsson-Wikmar L, Stenström CH (2005). Variability within and between evaluations of sacroiliac pain with the use of distraction testing. J Manipulative Physiol Ther. 2005 Nov-Dec;28(9):688-95.
  7. 7.0 7.1 Albert H, Godskesen M, Westergaard J (2000). Evaluation of clinical test used in classification procedures in pregnancy-related pelvic joint pain. Eur Spine J. 2000; 9(2):161-166
  8. 8.0 8.1 Kokmeyer DJ, Van der Wurdd P, Aufdemkampe G, Fikenscher TC (2002). The reliability of multitest regimens with sacroiliac pain provocation tests. J Manipulative Physiol Therapy. 2002;25(1):42-48
  9. 9.0 9.1 9.2 9.3 Ozgocmen S, Bozgeyik Z, Kalcik M, Yildrim A (2008). The value of sacroiliac pain provocation tests in early active sacroilitis. Clin Rheumatol. 2008;27:1275-1282
  10. 10.0 10.1 10.2 10.3 Robinson HS. Brox JI. Robinson R. Bjelland E. Solem S. Telje T (2007). The reliability of selected motion- and pain provocation tests for the sacroiliacjoint. Manual Therapy. 12(1):72-9, 2007 Feb.
  11. Physiotutors. Distraction Test | Sacroiliac Joint Provocation. Available from:
  12. Ham SJ, van Walsum DP, Vierhout PAM (1996). Predictive value of the hip flexion test for fractures of the pelvis. Injury, 1996, 27:543-544
  13. 13.0 13.1 Whiting P, Rutjes AWS, Reitsma JB, Bossuyt, Kleijnen J (2003). The development of QUADAS: a tool for the quality assessment of studies of diagnostic accuracy included in systematic reviews. BMC Medical Research Methodology 2003, 3:25
  14. Whitling P, Harbord R, Kleijnen J (2005). No role for quality scores in systematic reviews of diagnostic accuracy studies. BMC Med Res Methodol. 2005;5:19
  15. De Graaf I, Prak A, Bierma-Zeinstra S, Thomas S, Peul W, Koes B (2006). Diagnosis of lumbar spinal stenosis: a systematic review of the accuracy of diagnostic tests. Spine. 2006;31:1168-1176
  16. Sehgal N, Shah RV, McKenzie-Brown AM, Everett CR (2005). Diagostic utility of facet (Zygapophysial) joint injections in chronic spinal pain: a systematic review of evidence. Pain Physician. 2005;8:211-224
  17. Shah RV, Everett CR, McKenzie-Brown AM, Sehgal A (2005). Discography as a diagnostic test for spinal pain: a systematic and narrative review. Pain Physician. 2005;8:187-209
  18. Hardaker WT, Jr., Garrett WE, Jr., Bassett FH 3rd (1990). Evaluation of acute traumatic hemarthrosis of the knee joint. South Med J. 1990;83:640-644
  19. Hegedus EJ, Cook C, Hasselblad V, Goode A, McCrory DC (2007). Physical examination tests for assessing a torn meniscus in the knee: a systematic review with meta-analysis. J Orthop Sports Phys Ther. 2007;37:541-550
  20. van der Wurff P, Meyne W, Hagmeijer RHM (2000b). Clinical tests of the sacroiliac joint: A systematic methodological review. Part 2: Validity. Manual Therapy Volume 5, Issue 2, May 2000, Pages 89–96
  21. van der Wurff P, Meyne W, Hagmeijer RHM (2000a). Clinical tests of the sacroiliac joint: A systematic methodological review. Part 1: Reliability. Manual Therapy Volume 5, Issue 2, May 2000, Pages 89–96
  22. 22.0 22.1 Stuber KJ (2007). Specificity, sensitivity, and predictive values of clinical tests of the sacroiliac joint: a systematic review of the literature. J Can Chiropr Assoc. 2007 March; 51(1): 30–41.
  23. Laslett M, Aprill C, McDonald B, Young S (2005). Diagnosis of sacroiliac joint pain: validity of individual provocation tests and composites of test. Man Ther. 2005;10:207-218.
  24. Maigne JY, Aivaliklis A, Pfefer F (1996). Results of sacroiliac joint double block and value of sacroiliac pain provocation tests in 54 patients with low back pain. Spine 1996;21:1889-1892
  25. Schwarzer AC, April CN, Bogduk N (1995). The sacroiliac joint in chronic low back pain. Spine 1995;20:31-37
  26. Borowsky CD, Fagen G.(2008) Sources of sacroiliac region pain: insights gained from a study comparing standard intra-articular injection with a technique combining intra- and peri-articular injection. Arch Phys Med Rehabil. Nov;89(11):2048-56
  27. Murakami E, Tanaka Y, Aizwa T (2007). Effect of peri-articular and intra-articular lidocaine injections for sacroiliac joint pain: prospective comparative study. J Ortoped Science. 2007;12:274-280.