Validity and reliability of a novel device to evaluate balance and postural control - Quadrotics Poise Q10

Assessment of balance using force platform-based methods are crucial for diagnosis and treatment in the fields of physiotherapy. This study evaluated the validity and reliability of the Quadrotics Poise Q10 in measuring postural sway and limits of stability, using simultaneous assessments with the Bertec force platform in 40 healthy participants. Postural sway was evaluated under four conditions. Limits of stability were analysed in the four directions. Pearson's correlation analysis was used to assess the concurrent and absolute validity of the Quadrotics Poise Q10. Intra and Inter-Rater reliability were examined using intraclass correlation coefficients (ICC), standard error of measurement, and Minimum Detectable Change. Additionally Limits of Agreement and Bland-Altman plots were conducted. A strong relationship was observed in anteroposterior and mediolateral sway on both hard and soft surfaces, with eyes open and closed (p < 0.05). Moderate to strong correlations were found for all directions excursions during the limits of stability test (p < 0.05). Intra-rater reliability analysis demonstrated high reliability for postural sway (ICC:0.60-0.87) and excellent reliability for LoS (ICC:0.91-0.95). Inter-rater reliability was found to be high across all test conditions, with ICC values ranging from 0.67 to 0.83 for postural sway and excellent reliability for LoS in the right and left directions (ICC = 0.93 and 0.91, respectively) and high in the forward and backward direcions (ICC = 0.67-0.71). The study's findings indicate that the newly developed device is valid and reliable for evaluating limits of stability and postural sway. However, Bland-Altman analysis variations highlighted in lower agreement under more challenging test conditions.