Validation Of A Smartphone Application For Measuring Shoulder Internal Rotation And External Rotation Range Of Motion With Intra-Rater Reliability

Abstract

Assessing range of motion of the shoulder girdle is a critical skill needed by athletic trainers due to the complexity of the motions allowed at the joint. The process can be subjective with the majority of accepted techniques utilizing the clinician’s ability to determine bony landmarks of the patient. In recent years, tools have been created to make determining range of motion of the body valid and consistent. One of the most common tools used in the clinic setting to measure shoulder range of motion is the inclinometer. With the current technical age, there have been many smartphone applications created to mimic and serve as an inclinometer. Within the clinical setting, it is common practice for one clinician to measure a patient’s range of motion multiple times throughout a course of treatment. Therefore, the purpose of this study was to determine the validity of the smartphone application, “Clinometer” for measuring shoulder internal and external rotation range of motion using intra-rater reliability. An experienced Certified Athletic Trainer measured bilateral shoulder internal rotation and external rotation with a hand held goniometer and with the “Clinometer” smartphone application in 25 male participants, ages 18-23. Validation of the application and intra-rater reliability were assessed by using Pearson correlation coefficients. Smartphone validation was statistically significant for shoulder internal and external range of motion with values of 0.959 and 0.940 respectively. Intrarater reliability was statistically significant for external rotation with the goniometer and internal and external rotations with the application (0.804, 0.800, and 0.838). The results of this study indicate that there is no difference in the hand held goniometer and the “Clinometer” smartphone application for measuring shoulder internal and external range of motion. There is also good reliability in an experienced clinician for finding and measuring end points of shoulder internal and external rotation with the application as well as external rotation with the goniometer.