During an examination of a 3-month-old, the NP places the in…

During an examination of a 3-month-old, the NP places the infant in the supine position with the hips flexed 90 degrees and abducted while holding the legs by the thigh and gently adducting the leg while applying downward, lateral pressure. What is the name of the supplementary exam commonly performed in conjunction with the exam described?