FIGURE 4-9 Cardinal movements in the mechanism of labor with the fetus in vertex presentation (a) Engagement, descent, flexion, (b) Internal rotation, (c) Extension beginning (rotation complete), (d) Extension complete, (e) External rotation (restitution), (f) External rotation (shoulder rotation), (g) Expulsion. (Used with permission of Ross Products Division, Abbott Laboratories, Inc., Columbus, OH 43216, Clinical Education Aid No. 13.)
