A modified digital functional reach test device using an ultrasonic sensor for balance assessment: A test of validity and reliability

Abstract Study aim: Evaluation of dynamic balance is inferred to be compulsory for fall prevention in the elderly. Therefore, this study aimed to develop a modified digital functional reach test device using an ultrasonic sensor for balance assessment and to test validity and reliability of the newly developed tool to qualify psychometric properties. Material and methods: This study was a cross-sectional study of a convenient sample including 50 participants both males and females. Mean age of the participants was 51.20 ± 19.30 years. Reliability of the newly developed device was analysed using the intraclass correlation coefficient (ICC) and standard error of measurement (SEM). The criterion validity was also investigated using a yardstick mounted on the wall at a level of shoulder together with the MaxTraq® 2D motion analysis software. The modified digital functional reach test device using an ultrasonic sensor was correlated with the conventional FRT and the MaxTraq® 2D motion analysis. Results: The results presented that test-retest reliability of the modified digital functional reach test device was good reliability (ICC = 0.76) and low standard error of measurement (1.41) was found for test-retest reliability. The degree of agreement between the modified device, the conventional FRT, and the MaxTraq® 2D motion analysis was high (r = 0.71 and 0.77 respectively). Conclusions: The findings suggested that the modified digital functional reach test device using an ultrasonic sensor was a valid and reliable instrument for fall risk screening towards functional reach distance.