Providing a bodily injury-free experience might be a promising opportunity for the adoption of VR and force feedback-based equipment in a gym context. Nevertheless, it is still uncertain how these systems could compromise the users’ physical state and how they should react a posteriori.

This Graduation project begins with the exploration of the bodily injury risks associated with the Ethereal Engine, an ultimate VR-based equipment that seeks a revolution in the fitness industry. Resulting in four different clusters -collision, posture, balance loss and long-term exposure-related risks-, a study on the current market-ready technologies that could minimize these risks is performed together with an assessment on how safety can be boosted while keeping the experience’s engagement.

Thanks to the research, posture evaluation is selected as the challenge with a differential potential over the rest to bring Ethereal Engine to the next level, providing an experience in which bodily injury risks could be reduced, motivating users to adopt better postural habits when working out. Right after, a design vision is formulated, emphasizing the need for inspiring users to self-correct their posture instead of imposing rules in order to avoid possible immersion breakages.

In this context, three concepts are proposed, which present different feedback alternatives that vary in terms of explicitness, immediacy, and strictness. However, a priori there is no clear answer on which of these alternatives could most positively affect the experience. To overcome the knowledge gap an experiment that not only assesses the performance of the 16 participants but also their perception of the understandability, usefulness, performance, posture correction, general engagement, confusion and criticism of the feedback is conducted. During three different experiments where different feedback alternatives are assessed -immediate visual clues, statistics after certain repetitions, and immediate pop-up messages- participants are asked to perform 10 squats while lifting a water jug and receiving different scores depending on its displacement.

In order to do so, a partial prototype that allows for the first time to experience certain functionalities of the Ethereal Engine is developed. These functions are: a) a hybrid MoCap system that merges a Oculus Quest headset with a multi-camera-based skeletal tracking system -named MoCapForAll-. ; b) a calibration process that adjusts the range of motion according to the participant’s height; and, c) a demo game that enables a more intense workout while keeping track of your posture while squatting.

After discussing the results, including a calibration process that enables fair competitiveness and feedback at three different levels to communicate diverse information are spotted as desired features to include in the Ethereal Engine. Through these recommendations a virtual trainer that inspires users to self-correct their posture will be possible, and, subsequently, enabling a bodily injury-free experience.