This paper explores the design of an expressive visual instrument that embraces the unique movement style of a dancer living with physical disability. Through a collaboration between the dancer and an interaction designer/visual artist, the creative qualities of wearable devices for motion tracking are investigated, with emphasis on integrating the dancer's specific movement capabilities with their creative goals. The affordances of this technology for imagining new forms of creative expression play a critical role in the design process. These themes are drawn together through an experiential performance which augments an improvised dance with an ephemeral real-time visualisation of the performer's movements. Through practice-based research, the design, development and presentation of this performance work is examined as a 'testbed' for new ideas, allowing for the exploration of HCI concepts within a creative context. This paper outlines the creative process behind the development of the work, the insights derived from the practice-based research enquiry, and the role of movement technology in encouraging new ways of moving through creative expression.