Inclinometer Reliability for Shoulder Ranges of Motion in Individuals With Subacromial Impingement Syndrome

Objective This study aimed to determine the intra- and interrater reliability of active and passive range of motion in the shoulders of individuals with subacromial impingement syndrome using a digital inclinometer. Methods The raters evaluated active and passive range of motion in the shoulder of 50 individuals with unilateral subacromial impingement syndrome in movements including flexion, abduction, extension, external rotation in a neutral position, external rotation with the arm at 90° of abduction, and internal rotation with the arm at 90° of abduction. The tests were performed by 2 examiners on the same day, with a 10-minute interval, and were repeated by 1 examiner after a 2- to 4-day interval. Reliability was analyzed using the intraclass correlation coefficient (ICC 2,3 ). Results There was moderate to excellent interrater (ICC 2,3 = 0.50-0.95) and intrarater (ICC 2,3 = 0.74-0.94) reliability. In the interrater analysis, the standard error of measurement (SEM) ranged from 4.1° to 10°, the percentage SEM (%SEM) ranged from 2% to 17%, and the minimum detectable change ranged from 9.5° to 23.4°. In the intrarater analysis, the SEM ranged from 4° to 9.2°, %SEM ranged from 3% to 14%, and the minimum detectable change ranged from 9.3° to 21.4°. Conclusion The digital inclinometer showed moderate to excellent reliability for measuring active and passive range of motion in shoulders with unilateral subacromial impingement syndrome.