Assessment of Kinect V2 for elbow range of motion estimation in people with haemophilia using an angle correction model

INTRODUCTION: The joint range of motion (ROM) is an important clinical parameter used to assess the loss of functionality resulting from joint bleedings in people with haemophilia. These episodes require a close follow-up and, to decrease patients' hospital dependence, telemedicine tools are needed. Therefore, this study is aimed to analyse the validity of the Microsoft Kinect V2 sensor with corrected angle measurement to be used in the monitoring of elbow ROM in people with haemophilia. METHODS: A convenience sample of 10 healthy controls (CG) and 10 patients with haemophilia with elbow arthropathy (HG) participated in this study. Full ROM of elbow joints was measured in the frontal view with a 10-degree sweep using: (a) a clinical goniometer; (b) the Kinect V2; (c) the Kinect V2 with angle correction; and (d) using a photograph. Bland-Altman graphs (mean and 95% Limits of Agreement [LOA]) and Wilcoxon test were used to determine differences between measurements and groups. RESULTS: The angle-corrected Kinect V2 measurement removed the skew in the original data, reducing the average errors from 7.9° (LoA = -10.3°; 26.0°; CG) and 9.5° (LoA = -7.9°; 26.9°; HG) to -0.1° (LoA = -8.1°; 7.9°; CG) and -0.7° (LoA = -10.7°; 9.3°; HG). CONCLUSIONS: These error levels allow the use of Kinect V2 in the clinical practice. Kinect V2 with angle correction can complement the classical goniometry allowing an efficient and touchless measurement of ROM.