This practice-led research investigates a design framework within an artistic context for the implementation of Whole Body Interactive (WBI) performance systems that employ real-time motion capture technology. Following an Interaction Design perspective I engage in exploring the requirements for composers, dancers, musicians and performers and their expectations, within a series of transdisciplinary collaborative artistic projects. Integral to this investigation is a comprehensive review and analysis of the progression of interactivity in fine art, music, dance and performance practices, presented in this thesis. As I am particularly concerned with the seamless transfer of the tacit skills and the implicit knowledge of non-digital artists and practitioners to a WBI performance setting, my practical explorations emerged in the contexts of music improvisation - Untitled#1, contemporary dance - Untitled#2, contemporary music composition - Hiroshima, and traditional dance - Duende. Adopting a Holistic Design approach, the experience and knowledge gained from my first practical explorations led to the design and implementation of a WBI prototyping software environment called EnActor, used in tandem with the Orient wireless inertial motion capture system, developed by the Research Consortium in Speckled Computing, at the University of Edinburgh. EnActor provides a simple and effective solution to the problem of linking physical actions to rich digital media responses and can serve as a blueprint for the development of other WBI design software, since it has operated successfully as a prototype, addressing a wide range of WBI design briefs in various contexts. In this thesis I introduce the role of the WBI designer as a specialist interaction designer able to conceptualise WBI scenarios and implement complete systems that operate within various levels of body sensing and control. I also propose the development of WBI systems that are autonomous and unsupervised, and I explore various compositional concepts and mappings that are implemented as automatic, semi-automatic or manual modules and ultimately arranged into layers and to series of blocks that represent complete compositions. Following the understanding of interactivity as a property between systems, I identify the design of three basic types of WBI performance systems that differ in how a user engages with them: methodical, empirical and dialectic. Overall this research aims to facilitate designers and artists interested in the use of real-time motion capture systems in dance, music, theatre and performance art applications.