Seated flexion test

The tests for pelvic dysfunctions have fair specificity and variable sensitivity. The presence of a sacral dysfunction can obscure or exaggerate the findings for pelvic dysfunction. The standing flexion test can be falsely positive if there is an overwhelmingly positive seated flexion test and sacroiliac dysfunction. The depth of the sacral sulcus is not specific to pelvic dysfunction because a deep sulcus can also indicate a forward sacral torsion with the axis opposite to the deep sulcus, a unilateral sacral shear, as well as a posteriorly rotated ilium on the same side. A shallow sulcus can also indicate sacral dysfunction in addition to an anterior rotated ilium on that side. 

Unilateral sacral shears, also known as unilateral sacral flexions, have complicated axes that are still undergoing debate. However, the findings of deep sulcus and posterior ILA on the same side are quite typical (Fig. 60-12]. The seated flexion test also occurs to the same side and the sacroiliac dysfunction is ipsilateral. 

The femoral unit clamping block or jig was produced which it can flex at certain angle. The jig produced has the same lateral profile as the femoral unit. The femoral s jig has 5 holes which is to lock the femoral s jig at 5 flexion angle of knee flexion. At the back of the femoral unit, there are 2 pins which allows the femoral s jig to clamp the femoral unit. The femoral s jig is clamped by compression test machine (Universal Testing Machine, model LS-28101-UTM) [1]. The patellar s jig with a diameter central holes 14.45mm and depth of 5.5mm was clamp to the UTM machine. Then the articulate patellar seated into the patellar s jighole underneath the femoral unit and allowed to move freely in the hole to centralise the unit about the femoral surface. The two sheets of FUJI Prescale low stress film... 

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