Assessment of the Validity and Reliability of Reaction Speed Measurements Using the Rezzil Player Application in Virtual Reality

Virtual reality (VR) is widely used across various areas of human life. One field where its application is rapidly growing is sport and physical activity (PA). Training applications are being developed that support various sports disciplines, motor skill acquisition, and the development of motor abilities. Immersive technologies are increasingly being used to assess motor and cognitive capabilities. As such, validation studies of these diagnostic tools are essential. The aim of this study was to estimate the validity and reliability of reaction speed (RS) measurements using the Rezzil Player application (“Reaction” module) in immersive VR compared to results obtained with the SMARTFit device in a real environment (RE). The study involved 43 university students (17 women and 26 men). Both tests required participants to strike light targets on a panel with their hands. Two indicators of response were analyzed in both tests: the number of hits on illuminated targets within a specified time frame and the average RS in response to visual stimuli. Statistically significant and relatively strong correlations were observed between the two measurement methods: number of hits (rS = 0.610; p < 0.001) and average RS (rS = 0.535; p < 0.001). High intraclass correlation coefficients (ICCs) were also found for both test environments: number of hits in VR (ICC = 0.851), average RS in VR (0.844), number of hits in RE (ICC = 0.881), and average RS in RE (0.878). The findings indicate that the Rezzil Player application can be considered a valid and reliable tool for measuring reaction speed in VR. The correlation with conventional methods and the high ICC values attest to the psychometric quality of the tool.