Uterus not in tetanus nor contracted down over the child.
The fœtus must be movable.
The head should not be engaged.
The Walcher position is produced by bringing the patient down to the end of the table so that the sacrum rests upon the edge. The thighs and legs are allowed to hang down of their own weight and the patient is restrained from falling off by traction upwards on the axillæ.
In the Walcher position the diameter of the pelvic inlet is increased from ⅓ to ½ inch (1 cm.) and thereby the delivery of heads that otherwise could not pass becomes possible.
In addition to the Walcher position other measures may be required to help the head through. Thus, traction from below may be carried to the limit of safety and in spite of the Walcher position the head may not pass the inlet.
Then pressure from above is added. This maneuver will have to be executed in many cases by the nurse.
The fingers palpate the head above the pubes. Then one or both fists are placed upon the abdomen over the head and force is exerted to crowd the head down into the pelvis. This is known as the Wiegand compression.
For the operations destructive to the child, craniotomy or decapitation, the same arrangements are made.
