What is the purpose of palpating the PSIS during a back view examination of the pelvis?

Palpating the Posterior Superior Iliac Spine (PSIS) during a back view examination of the pelvis is primarily intended to compare pelvic level. The PSIS is a bony landmark on the pelvis that helps determine if there is any asymmetry or tilt. By palpating both sides of the PSIS, an examiner can identify whether one side is higher or lower than the other, which could indicate issues such as pelvic misalignment or uneven weight distribution.

This assessment is crucial for understanding the overall alignment of the pelvis, which can have a significant impact on posture and alignment throughout the body, influencing areas like the spine and lower limbs. Identifying any asymmetries can guide further assessment and intervention, making this palpation a key component of a thorough postural analysis.