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Special Test

Standing Flexion Test

What is Standing Flexion Test?

Standing flexion test (also called Piedallu test) is used to assess sacroiliac joint function.

See Also: Three-Phase Hyperextension Test

How do you do the Standing Flexion Test?

  • Standing flexion test is done with the patient stands with his or her back to the examiner.
  • The examiner’s thumbs simultaneously palpate both posterior superior iliac spines.
  • The patient is asked to slowly bend over while keeping both feet in contact with the floor and the knees extended.
  • The examiner observes the position and/or motion of both iliac spines as the patient’s torso bends forward.
Standing Flexion Test procedure

What does a positive Standing Flexion Test mean?

  • The sacrum rotates relative to the ilia around a horizontal axis in the sacroiliac joints, this motion is referred to as “nutation.”
  • In normal patients with mobile sacroiliac joints, the two posterior superior iliac spines will be level with each other throughout the range of motion when the patient bends over.
  • If nutation does not occur in the sacroiliac joint on one side, the posterior superior iliac spine on that side will come to rest farther superior with respect to the sacrum than the spine on the contralateral side.
  • Where nutation fails to occur or this relative superior advancement is observed, this is usually a sign of a blockade in the ipsilateral sacroiliac joint.
  • Bilateral superior advancement can be simulated by bilateral shortening of the hamstrings.

Standing Flexion Test Accuracy

The sensitivity and specificity of the standing flexion were poor. 1

Seated Flexion Test

Seated Flexion Test is purported by osteopaths to help distinguish between a SI lesion and an iliosacral lesion when compared with the results of the standing flexion test.

The patient sits on a hard surface with the legs over the end of the table and feet supported. In this position, innominate motion is severely abbreviated, because sitting places the innominates near the end of their extension range. The test is performed as follows. Each PSIS (posterior superior iliac spine) is palpated with the thumb placed under it inferiorly (caudally). The patient then bends forward at the waist.

Provided there is no impairment in the SIJ or the lower lumbar spine, as the patient bends forward, both thumbs should move superiorly (cranially). If the joint is blocked, it moves superiorly further in relation to the other side.

A similar test, referred to as the sitting bend over test or sitting forward flexion test, is performed in the same manner except the patient is seated on a soft surface

This examination has been shown to lack reliability, have poor sensitivity, and have low specificity as a result a low false positive rate.

A study by Levangie determined the sensitivity to be 9%, the specificity to be 93%.

Seated Flexion Test
Seated Flexion Test


  • When evaluating this superior advancement phenomenon, the examiner must consider or exclude possible asymmetry of the pelvis and hips.
  • Pelvic obliquity due to a difference in leg length should be compensated for by placing shims under the shorter leg.


  1. Nejati P, Sartaj E, Imani F, Moeineddin R, Nejati L, Safavi M. Accuracy of the Diagnostic Tests of Sacroiliac Joint Dysfunction. J Chiropr Med. 2020 Mar;19(1):28-37. doi: 10.1016/j.jcm.2019.12.002. Epub 2020 Sep 12. PMID: 33192189; PMCID: PMC7646135.
  2. Levangie PK. Four clinical tests of sacroiliac joint dysfunction: the association of test results with innominate torsion among patients with and without low back pain. Phys Ther. 1999 Nov;79(11):1043-57. PMID: 10534797.
  3. Clinical Tests for the Musculoskeletal System 3rd Edition.
  4. Dutton’s Orthopaedic Examination, Evaluation, And Intervention 3rd Edition.
Last Reviewed
October 6, 2021
Contributed by

Orthofixar does not endorse any treatments, procedures, products, or physicians referenced herein. This information is provided as an educational service and is not intended to serve as medical advice.

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