Adding Pieces to the Puzzle: A Commentary

In Jensen’s theme paper she did an excellent job of outlining and explaining ways in which motor developmentalists can use the tools of biomechanics and engineering to address research questions. We extend her thorough efforts in two ways. First, we highlight the communication value provided by the precision of biomechanics terminology, and second, we reinforce the need to embed motion (the kinematics and kinetics) in context and function in order to understand the complexity of behaviour. We illustrate how one biomechanical tool, mechanical models, can facilitate this and provide insight to the development of control. Copyright # 2005 John Wiley & Sons, Ltd.