Infra-Pubic Angle

Wide and narrow IPA types can both show limited hip extension, but the article says they require different treatment. A wide IPA presentation is associated with hypermobility and greater degrees of freedom. The orientation of the innominate governs the width of the infra-pubic angle. Movement limitations can make the infra-sternal angle and infra-pubic angle match rather than oppose each other. A narrow infrapubic angle biases the femurs toward extension, adduction, and external rotation under the article's normal mechanics model. A wide infrapubic angle normally biases the femurs toward flexion, adduction, and internal rotation. A wide infra-pubic angle is associated with posterior innominate rotation and sacral nutation. The femoral position associated with a narrow infrapubic angle is described as the close-packed position of the hip. A narrow infra-pubic angle is associated with anterior innominate rotation. With a wide infrapubic angle, the femur may compensate by migrating into external rotation to widen the base of support and improve hip congruence. A narrow IPA presentation rests in anterior innominate rotation and sacral counternutation. Normal mechanics involve the infr…