A protocol for assessing virtual and mixed reality environments with real-time electromyographic (EMG) biofeedback during upper limb physical exercises

Abstract

This paper describes a protocol for a controlled laboratory study designed to evaluate how immersive real-time electromyographic (EMG) biofeedback affects standardized shoulder exercise performance and user experience in healthy adults. Participants aged 20–30 years will be randomly allocated to virtual reality (VR), mixed reality (MR), or a non-immersive control condition. Within the immersive arms, each participant will experience three EMG visualization formats (an anatomically mapped avatar, a dynamic bar display, and a live waveform graph) in randomized order. During five standardized shoulder exercises, bilateral deltoid activity will be recorded using six wireless EMG sensors, while three-dimensional kinematics will be captured with an optical motion-capture system. Outcomes will include joint-angle accuracy, normalized muscle activation, compensatory motion, range of motion, movement speed, task completion time, together with perceived exertion, simulator sickness, and system usability. By integrating synchronized EMG and motion-capture data with immersive feedback delivery, this protocol provides a reproducible framework for comparing VR and MR biofeedback environments and evaluating how visualization format may influence exercise execution and user experience.• Compares VR, MR, and non-immersive shoulder exercise conditions.• Evaluates avatar, bar, and waveform EMG visualization formats.• Combines EMG, motion capture, and subjective assessments.