Evaluation of the Ability of Physical Therapists to Palpate Intrapelvic Motion With the Stork Test on the Support Side

Abstract

Clinical indicators of pelvic girdle dysfunction are limited. However, research has shown that the pattern of intrapelvic motion is altered during single-leg support in subjects with pelvic girdle pain (PGP). Functionally, no relative motion should occur within the pelvis during load transfer, whereas anterior rotation of the innominate bone relative to the sacrum occurs during weight bearing in the presence of PGP. The aim of this study was to investigate whether the pattern of intrapelvic motion could be detected reliably during a new clinical assessment test for functional load transfer: the Stork Test on the support side. Three physical therapists were randomly assigned to palpate the motion of the innominate bones and sacrum in 33 subjects during the Stork Test on the support side. The direction of bone motion was indicated on 2-point and 3-point scales. When a 2-point scale was used, intertherapist agreement on the pattern of intrapelvic motion occurring during load transfer showed good reliability (left kappa=.67, right kappa=.77), and the percentage of agreement was high (left=91.9%, right=89.9%). A 3-point scale resulted in moderate reliability for both the left and the right sides (left kappa=.59, right kappa=.59), and the percentage of agreement decreased to 82.8% (left) and 79.8% (right). The ability of the physical therapists to reliably palpate and recognize an altered pattern of intrapelvic motion during the Stork Test on the support side was substantiated. The ability to distinguish between no relative movement and anterior rotation of the innominate bone during a load-bearing task was good. Further research is needed to determine the validity of this test for detecting pelvic girdle dysfunction.