Five components can be differentiated in the development of flexible flatfeet. In children, a slight form of flatfeet is physiological; however, the more pronounced form requires correction. The criteria for the use of insoles are discussed, and the decisive factor in making this decision is to examine the child in normal standing or walking position. The principles of correction and various types of insoles are presented, and the advantages and disadvantages an discussed. Attention is paid in particular to the role of the shoe when the foot is in the standing position or in motion. In addition, questions arising from the use of insoles are dealt with and foot exercises presented.