Virtual patient assessment will inevitably require smartphone technology to remotely measure knee range of motion. We conducted an experiment to analyze the impact of observer position relative to the flexed knee on the perceived angle measured using an electronic application (Dr. Goniometer) for iPhone. Two observers measured the apparent knee flexion angle from 7 different positions at 3 different heights relative to the center of the knee joint. Intraclass correlations were calculated to evaluate the intraobserver and interobserver variability using two-way mixed-effects models.
Virtual patient assessment will inevitably require smartphone technology to remotely measure knee range of motion. We conducted an experiment to analyze the impact of observer position relative to the flexed knee on the perceived angle measured using an electronic application (Dr. Goniometer) for iPhone. Two observers measured the apparent knee flexion angle from 7 different positions at 3 different heights relative to the center of the knee joint. Intraclass correlations were calculated to evaluate the intraobserver and interobserver variability using two-way mixed-effects models.