Background: Falls are common in elderly individuals and those with neurological conditions like Parkinson's disease. Parkinson's disease causes postural instability and mobility issues that lead to falls and reduced quality of life. The fear of falling (FoF), a natural response to unstable balance, can exacerbate postural control problems. However, evaluating FoF relies primarily on subjective self-reports due to a lack of objective assessment methods.

Objectives: This mixed-methods feasibility study aims to develop an objective method for assessing fear of falling during motion and walking using virtual reality. This protocol examines a range of FoF-related responses, including cognitive, neuromuscular, and postural stability factors.

Methods: Individuals without and with Parkinson's disease will complete questionnaires, movement tasks, and walking assessments in real and virtual environments where FoF can be elicited using virtual reality (VR) technology. Data from center-of-pressure measurements, electromyography, heart rate monitoring, motion capture, and usability metrics will evaluate the method's acceptability and safety. Semi-structured interviews will gather participants' and researchers' experiences of the protocol. Discussion: This method may allow accurate assessment of how FoF impacts movement by measuring cognitive, neuromuscular, and postural responses during gait and motion. Virtual environments reproduce real-life scenarios that trigger FoF. Rigorously assessing FoF with this approach could demonstrate its ability to quantify the effects of FoF on movement.

Conclusions: This protocol aims to improve FoF assessment by evaluating multiple responses during movement in virtual environments. It addresses current measures' limitations. A feasibility study will identify areas for improvement specific to Parkinson's disease. Successful validation could transform how FoF is evaluated and managed.