A reliability and validity study on upper limb range of motion measurement using mobile sensor compared with goniometers

Abstract

Introduction: The use of tele-rehabilitation devices to aid physiotherapy has gained popularity in recent years. In particular, measuring limb range of motion with a wearable mobile sensor can facilitate rehabilitation therapies by providing more efficient progress monitoring and reducing clinicians’ workload. This study aimed to examine the test-retest reliability and validity of using a wearable mobile sensor to measure upper limb range of motion (ROM). Materials and methods: Participants were recruited by convenient sampling. They were instructed to perform four kinds of upper limb movements including shoulder flexion, abduction, external rotation and elbow flexion, from which the ROM was measured by Mobile sensors REBEE (XCLR8 Technologies) and a standard goniometer (Model 12-1000) in each movement. Each kind of movements and the two ROM measurements were performed twice for the evaluation of test-retest reliability using Intraclass Correlation Coefficients (ICC). Pearson's correlations were computed between the ROM measured by the mobile sensors and the goniometer in each movement to assess construct validities of the mobile sensors. The agreement (95% mean difference) between the two sets of measurement was illustrated by Bland-Altman plots. Results: Thirty-four asymptomatic young Asian adults (15 males) participated in this study (Mage ± SD, 24.2 ± 3.82 years). The ICC for the ROM measured by the sensors were between 0.94 and 0.99, p <0.01 and for the goniometer measurements were between 0.95 and 0.98, p <0.01 in the four movements, indicating excellent reliability in both measurement methods. The Pearson's correlation between the sensor’s and goniometric ROM measurements in four kinds of movements ranged from r =0.96 to 0.99, p <0.01, indicating a very strong construct validity for using the mobile sensors to measure upper limb ROM. The mean difference between the two measurements ranged from 0.13 degrees to 7.6 degrees. Conclusions: The results demonstrated that measuring upper limb ROM using the mobile sensors by non-healthcare trained students were as reliable and valid as using the standard universal goniometers by healthcare trained students. The findings implied that the wearable mobile sensors possibly allow non-healthcare trained carers to measure clinically useful, reliable and valid upper limb ROM from patients, which may facilitate symptom monitoring and improve the efficiency of the rehabilitation process.