Determining the reliability and validity of a new method for measuring upper extremity joint range of motion in patients with burn injury using a tracking system

DesignA cross-sectional study.SettingPatients with burn injuries often present with joint contracture caused by hypertrophic scars. To assess the patient's degree of disability or outcome to rehabilitation treatment, various objective assessment tools are used, such as a standard goniometer, which is often used for measuring joint range of motion; however, measurements using a handheld goniometer may have a large margin of error depending on the therapist's experience. Herein, the reliability and validity of a novel marker-based system were investigated for evaluating joint range of motion in patients with burn injuries.ParticipantsIn total, 48 participants with joint contractures in the shoulder, elbow, and wrist owing to hypertrophic scars after thermal injury were enrolled.InterventionUpper extremity joint range of motion was measured using a goniometer and optical motion capture system (Session 1), followed by remeasurement 2 days later (Session 2).Main measuresTwenty-two reflective markers were attached to the upper limbs, and motion analysis was measured using eight infrared cameras.ResultsNo statistical differences were detected between the range of motion values measured using the two methods. The measurements based on the optical motion capture system showed excellent intra-rater reliability.ConclusionsThe findings of this study highlight the value of the motion capture system as a tool to objectively evaluate the joint range of motion in patients with contractures caused by burns.This study was registered at ClinicalTrials.gov (Identifier: NCT05881876).