1 Introduction -- 2 Basics of handedness -- 3 Determining handedness -- 4 Possible causes of changing hand use -- 5 The development of the handedness profile -- 6 The current handedness profile -- 7 Proposal of a differentiation system "handedness type with variants" for the analysis of changing hand use -- 8 Ideas for intervention with handicapped children -- 9 Case studies from the field -- 10 A panorama: implication for practice, theory, and research.