What is the correct LOD for palpating sacral nutation?

The correct line of drive (LOD) for palpating sacral nutation is posterior-anterior (P-A) and inferior-superior (I-S). Sacral nutation refers to the movement of the sacrum in relation to the pelvis, where the sacral base moves anteriorly and inferiorly as the ilia move closer during certain movements like flexion of the trunk or hips.

To efficiently palpate this movement, applying a P-A vector targets the sacral base while the I-S vector focuses on the sacral apex. This combination facilitates understanding the nutation pattern since the sacrum tilts forward when nutation occurs. By palpating in the direction of sacral nutation using the specified vectors, one can feel the normal motion of the sacrum as it engages more with the ilia, which is crucial in assessing the pelvis and diagnosing dysfunctions associated with it.

Thus, utilizing the P-A and I-S line of drive captures the essence of the biomechanical movements involved in sacral nutation, providing clinicians with vital information about the patient's sacral positioning and movement capabilities.