Investigation of the validity and reliability of the wrist and hand range of motion measurements with internet-based goniometer

The purpose of this study was to investigate the validity and reliability of Internet-based goniometer in the range of motion measurement of wrist and hand. Twenty-six healthy individuals aged 19-57 years participated in the study. Measurements were taken on 49 hands. The validity of the method was evaluated by examining the agreement between the internet-based goniometric measurement and the universal goniometer measurement results, which is accepted as the gold standard. There was a strong agreement between the internet based goniometer and the universal goniometer (ICC=0,686-982) and a positive middle to very high correlation (r=0,522-964; p<0,001). There was a significant difference in forearm supination; thumb MCP extension; 4th Finger MCP flexion/extension, PIP flexion and DIP flexion; 5th Finger DIP flexion between the Internet-based goniometer and the universal goniometer. Bland-Altman plots further showed the agreement between two measurement methods. The intra-rater reliability (ICC=0,797 - 0,997) and inter-rater reliability (ICC=0,764-0,989) was found strong. The standard error of measurements were low (1,445 and 4,158). Minimal detectable chance ranged between 4,005 and 11,524. The internet-based goniometer has been found to be a valid and reliable method for measuring wrist and hand range of motion. The standardized digital measurement method could provide additional benefits to physiotherapist in telemonitoring. Keywords: telerehabilitation; telemonitoring; hand rehabilitation; protractor; measurement; screenshots; photography;