Reliability and validity of the ratings of perceived stability scale as a measure of balance exercise intensity in persons with multiple sclerosis

Purpose: The study aimed to determine the test-retest reliability and concurrent validity of the Ratings of Perceived Stability (RPS) scale as a measure of balance exercise intensity in persons with multiple sclerosis (MS). Methods: Twenty participants with MS (mean age: 58.1 +/- 15.29; 60% female) performed 14 balance tasks on two separate occasions wearing body-worn inertial sensors and rated their perceived stability for each task. Sensor data included sway velocity and angle, gait speed, turn velocity, and lean angle. Intraclass correlation coefficients (ICC) and Spearman rank correlations (rs) were employed to assess reliability and validity, respectively. Results: The RPS showed good to excellent test-retest reliability (ICC> 0.75) on 12 out of the 14 tasks. The stability ratings revealed moderate relationships with postural sway outcomes in static balance tasks (rs: 0.49 to 0.77) and weak to moderate associations with gait speed (rs: -0.69 to -0.14). Ratings of stability were also strongly related to turn velocity (rs= -0.77) and moderately related to lean angle (rs= 0.58). Conclusions: The RPS scale offers a promising clinical tool to measure balance exercise intensity for persons with MS. This standardized scale allows for tailored balance training with a novel means for exercise monitoring and progression in this population.