Construct validity and reliability of tests for sacroiliac dysfunction: standing flexion test (STFT) and sitting flexion test (SIFT).

Context: Sacroiliac dysfunction is characterized by a hypomobility of the range of motion of the joint, followed by a positional change regarding the relationship between the sacrum and the iliac. In general, the clinical tests that evaluate the sacroiliac joint (SIJ) and its dysfunctions lack validity and reliability values.

Objectives: This article aims to evaluate the construct validity and intra- and inter-rater reliability of the standing flexion test (STFT) and sitting flexion test (SIFT).