Obstructed Labour from Dorsal Displacement of the Arm

case of arm displacement, which did not, however, strictly belong to the same category, seeing that the forearm had fallen down below the head, although the arm occupied an unusual position, and was placed in relation to the posterior instead of the anterior part of the head. Reference to these, or some of these cases, form the staple of what systematic writers give when treating of this subject; and in Crede's7 exposition of the disturbances of labour from displacement of the arms along with the presenting head, he describes the dorsal displacement in this single sentence : " In very rare cases the upper arm places itself as far as the elbow straight