Validity of a novel web application for measuring active range of motion and its reliability as a self-measurement method in telerehabilitation.

PURPOSE: As a result of the emergence of Artificial Intelligence (AI), new applications for measuring active range of motion (AROM) in telerehabilitation (TR) are being developed. The main objectives of the present study were to evaluate the validity of the TRAK® web application for measuring AROM, to assess its reliability as a self-measurement tool for subjects undergoing TR, and to examine the influence of the subjects' technological skills on the self-measurement process. METHODS: To this end, a cross-sectional observational study was conducted with healthy subjects. Sixty-five volunteer subjects were recruited and divided into two groups based on their technological skills (≤35 years and ≥ 55 years). Thirteen active joint movements were measured by TRAK® in two sessions, with each session being at least one week apart. Validity was assessed in the first session, during which the AROM data obtained by TRAK® were compared with the data obtained from a subsequent video analysis by Kinovea®. In this first session, the physiotherapist supervised the correct execution of the movement. In the second session, the participants repeated the AROM measurements independently and autonomously, following the instructions given by TRAK®, to analyse the reliability of the tool for TR self-measurement. RESULTS: Regarding validity, TRAK® showed good to excellent correlation (ŕs range = 0.739 to 0.987) and root mean square error (RMSE) < 4.74°for eleven out of thirteen movements in the younger group. In the older group, TRAK® obtained good to excellent correlation (ŕs range = 0.703 to 0.928) and RMSE < 4.95°for ten movements. Concerning reliability, however, TRAK® showed SEM percentages above 10% for multiple movements in both populations in its TR modality. CONCLUSION: TRAK® proved to be a valid tool for measuring multiple joint movements regardless of the subject's technological abilities, but was unreliable for assessing AROM in TR.