Musical steps: a piano-based augmented reality exergame exploring play modes for lower-limb exercise

The growing demand for lower-limb rehabilitation and the increasing focus on health maintenance have highlighted the challenge of effectively engaging users in exercise through interactive technologies. This study presents Musical Steps, an innovative augmented reality (AR) exergame that integrates music with standing knee raise exercises, using an interactive piano-playing theme to enhance both physical activity and user engagement. In contrast to many existing lower-limb exergames, we conducted a controlled within-subject study in which 36 healthy adult participants performed standing knee-raise exercises under three conditions: No Game (no AR feedback), Free Play, and Guided Play. Physical activity was measured using raise count and average knee-raise height, while subjective experiences were assessed using the Game Experience Questionnaire (GEQ) and brief interviews. Results indicate that Musical Steps was associated with higher physical activity measures and more positive user experience ratings compared to the no-game condition, with each mode demonstrating unique strengths. The Guided Play mode yielded a better user experience and a higher raise height. The inclusion of “guiding objects” in this mode provided clear game objectives, which effectively stimulated exercise motivation and enhanced persistence, especially in scenarios requiring structured guidance. In contrast, Free Play supported greater autonomy, resulting in higher raise count. This novel integration of music and AR gameplay not only improved movement amplitude and engagement in healthy adults but also provided valuable insights for future interactive exergame design.