Smartphone applications for the evaluation of pathologic shoulder range of motion and shoulder scores—a comparative study

Hypothesis and background: Accurate measurement of range of motion (ROM) is important in evaluating a pathologic shoulder and calculating shoulder scores. The aim of this study was to establish the reliability and validity of different smartphone applications (apps) in assessing pathologic shoulder ROM and to determine whether differences in recorded ROM measurements affect calculated shoulder scores. The authors hypothesized that there is no difference between shoulder ROM assessment methods and calculated shoulder scores. Methods: In this nonrandomized controlled clinical trial, ROM of 75 participants with a history of shoulder disease (21 women, 54 men) was assessed using a smartphone inclinometer and virtual goniometer, a standard goniometer, and clinicians’ visual estimation. Shoulder strength was assessed, and Constant-Murley (CM) and University of California–Los Angeles (UCLA) shoulder scores were calculated. Results: Independent of diagnosis or operation, all cases (except for passive glenohumeral abduction of unstable shoulders) showed excellent intraclass correlation coefficients (>0.84). Interobserver reliability was excellent for all ROM measures (intraclass correlation coefficient > 0.97). All modalities had excellent agreement to values attained with the universal goniometer. There were no differences for the calculated CM or UCLA scores between the modalities employed to measure ROM. Conclusions: A smartphone inclinometer or virtual goniometer is comparable to other clinical methods of measuring pathologic shoulder ROM. Clinicians can employ smartphone applications with confidence to measure shoulder ROM and to calculate UCLA and CM scores. The apps are also available to patients and may be a useful adjunct to physiotherapy, especially in cases of limited access to health care services.