ABSTRACT
This chapter categorizes the voluntary movements of infancy, and describes the development of head control during infancy. The first signs of voluntary movement are slight: movements of only the head, neck, and eyes. Nevertheless, after these first cortically controlled movements appear, the voluntary movements become increasingly prevalent and instrumental in enabling children to move in their environment. The voluntary movements of infancy are sometimes called rudimentary movements because they are the "rudiments" of future, more advanced movement forms. Like all the voluntary movements of infancy, locomotion develops in a somewhat predictable progression. However, although the progression generally is similar for all children, the rate at which these movement skills are acquired may vary considerably. The rate of acquisition for all voluntary movements during infancy may vary, but the differences among children for attaining prone locomotor movements are especially great.
