The Movements at the Sacro‐Iliac Joints and their Importance to Changes in the Pelvic Dimensions During Parturition

Pelvimetry in Breech and Cephalic Presentation

“…By excluding cases with a small pelvis clinically, the selection of the normal group may be biased, tending to give larger values than the true mean. However, the difference is probably small, and the results are well within the range given in other reports (BORELL & FERNSTROM 1960, BORELL & RADBERG 1964, DIEHL & FERNSTROM 1966. It is quite evident that no great difference exists between the measurements of the present two groups.…”

“…It is known that moulding of the pelvis occurs during parturition (BORELL & FERNSTROM 1957), so that both the sagittal inlet and the outlet diameters increase by up to 10 mm when the head passes. Much smaller changes of the transverse diameters have been reported.…”

The aging process in the sacroiliac joint: helical computed tomography analysis

“…It moves synergically with the operating muscle of the spine or hip joint. 1,7,10,16,18,20,22 The long axis of the sacroiliac joint is tilted forward at a 50° angle, and outward at a 20° angle from the vertical line, opening outward at a 16° angle on the horizontal plane. Because the sacroiliac joint has a structure in which the direction of the load relative to the articular surface is irrational, as the joint surface is not perpendicular to the trunk load axis, it is likely to incur more degenerative changes than other weight-bearing joints.…”

Randomised trial comparing the upright and supine positions for the second stage of labour

“…Considerable interest has recently been expressed in different positions during the second stage of labour 1 . Physiological advantages have been claimed for non‐recumbent labour, including an increase in pelvic dimensions 2–4 , smaller risk of aorto‐caval compression 5 , better ‘alignment’ of the fetus during passage through the pelvis 6 , more efficient uterine contractions 7,8 , and enlisting the force of gravity.…”