Reliability and Validity of a Smartphone Device and Clinical Tools for Thoracic Spine Mobility Assessments

Quantifying thoracic spine mobility with reliable and valid tools is a challenge for clinicians in practice. The aim of this study is to determine the reliability and validity of a smartphone device, bubble inclinometer and universal goniometer to quantify the static kyphotic curve and active range of motion of the thoracic spine. A total of 17 participants (mean age = 23.7 ± 2.3 years) underwent repeated measurements with three raters, on three separate days performing the lumbar-locked trunk rotation, standing full extension, standing full flexion, standing relaxed curve and seated trunk rotation assessments. Mostly "Good" to "Excellent" intra-rater (ICC ranging from 0.624 to 0.981) and inter-reliability (ICC ranging from 0.671 to 0.968) was achieved with the smartphone and clinical tools. "Excellent" validity (ICC ranging from 0.903 to 0.947) with the smartphone was achieved during lumbar-locked trunk rotation and standing relaxed curve assessment. "Good" validity (ICC ranging from 0.836 to 0.867) of the smartphone was achieved during the seated trunk rotation. The Samsung s9+ smartphone with the iSetSquare mobile application is a reliable and valid tool to use for clinical assessments assessing thoracic spine mobility.