Which of the following describes the Compression step of the Cluster of Laslett?

• A. Patient seated with knees apart
• B. Patient supine with pressure on ASISs
• C. Patient side lying with downward pressure on pelvis
• D. Patient standing with feet together

Answer: (C)

The Compression step of the Cluster of Laslett is described accurately by the option indicating the patient is side lying with downward pressure on the pelvis. This particular positioning and technique are utilized to assess the sacroiliac joint and to provoke the specific symptoms associated with sacroiliac dysfunction.

By applying pressure on the pelvis while the patient is in a side-lying position, the examiner can create a shear force through the sacroiliac joint, which can elicit pain if there is an underlying dysfunction. This method allows the clinician to isolate the response of the sacroiliac joint to compression, providing valuable information regarding the source of the patient's discomfort.

The other options, while they may represent various positions used in physical assessments or different testing strategies, do not adequately capture the specific mechanics and purpose of the Compression step within the context of the Cluster of Laslett. The correct approach emphasizes the importance of stress on the joint while maintaining specific positioning to yield accurate diagnostic insights.