Physical theory as a basis for successful rotation of fetal malpositions and conversion of fetal malpresentations.

Maternal posturing, in which a pregnant or laboring woman assumes specific postures with the intention of altering the position and/or presentation of the fetus within the uterus, is a safe alternative to operative procedures recommended in cases of fetal malpositions and malpresentations. Clinicians and researchers are more likely to help pregnant women understand and perform posturing correctly if they comprehend the theoretical underpinnings of the technique. In maternal posturing, the forces of gravity and buoyancy combine to form a couple that overcomes frictional forces and/or obstructions to allow the fetus to rotate within the uterus to an optimal position or presentation. Integrating an understanding of these physical processes into clinical practice and research according to the recommendations provided here should lead to greater success in correcting malpositions and converting malpresentations.